1 00:00:02,880 --> 00:00:05,280 We're a nation of biscuit lovers. 2 00:00:05,280 --> 00:00:08,360 This year, we'll work our way through enough of them 3 00:00:08,360 --> 00:00:10,520 to fill over 30,000 lorries! 4 00:00:12,440 --> 00:00:16,920 That means we Brits are tucking into 90 million biscuits a day, 5 00:00:16,920 --> 00:00:19,160 more than any other country in Europe. 6 00:00:21,000 --> 00:00:25,280 Whether you prefer them smothered in chocolate or plain and simple, 7 00:00:25,280 --> 00:00:27,040 everyone's got their favourite. 8 00:00:28,320 --> 00:00:32,200 And where's the best place to find out how they're made? 9 00:00:32,200 --> 00:00:35,600 How about the largest biscuit factory in Europe? 10 00:00:41,160 --> 00:00:43,320 I'm Gregg Wallace, and tonight, 11 00:00:43,320 --> 00:00:46,080 I'll join the race to keep up with demand. 12 00:00:46,080 --> 00:00:49,960 Do you know how many biscuits are passing our nose every minute? 13 00:00:49,960 --> 00:00:51,200 Over 3,000. 14 00:00:52,720 --> 00:00:54,280 I'm Cherry Healey, 15 00:00:54,280 --> 00:00:58,600 and I'm going to be making a very expensive biscuit-cutter 16 00:00:58,600 --> 00:01:01,520 out of thousands of pounds' worth of bronze. 17 00:01:01,520 --> 00:01:04,560 And answering the ultimate question. 18 00:01:04,560 --> 00:01:07,520 Are you a dunker or not a dunker? 19 00:01:07,520 --> 00:01:12,280 I get scientific proof that dunking makes your biscuit taste better. 20 00:01:12,280 --> 00:01:15,080 This is not a comfortable biscuit-eating experience. 21 00:01:16,360 --> 00:01:19,240 And historian Ruth Goodman's going back in time 22 00:01:19,240 --> 00:01:21,560 to when biscuits could cure the sick. 23 00:01:22,840 --> 00:01:25,680 "Being full of wind and out of order, 24 00:01:25,680 --> 00:01:27,400 "and there called for a biscuit." 25 00:01:29,800 --> 00:01:34,760 80 million biscuits are baked in this factory every single day. 26 00:01:34,760 --> 00:01:38,000 And we're going to reveal what a mammoth task that is. 27 00:01:38,000 --> 00:01:40,400 Welcome to Inside The Factory. 28 00:02:01,160 --> 00:02:04,640 This is the McVitie's factory in Harlesden, North London, 29 00:02:04,640 --> 00:02:12,040 where 580 workers churn out 2,500 tonnes of biscuits every week! 30 00:02:13,080 --> 00:02:17,640 That's over a quarter of all the biscuits we consume in the UK. 31 00:02:17,640 --> 00:02:20,760 They make 22 different varieties here. 32 00:02:20,760 --> 00:02:24,880 From hobnobs and rich teas to savoury snacks and mini-cheddars. 33 00:02:27,280 --> 00:02:30,920 Tonight we'll learn how they make the nation's favourite, 34 00:02:30,920 --> 00:02:32,600 the chocolate digestive. 35 00:02:32,600 --> 00:02:35,680 Which is nice, because that's my favourite too. 36 00:02:40,400 --> 00:02:45,160 This 50,000-square-metre factory opened back in 1902. 37 00:02:45,160 --> 00:02:48,880 It's been making chocolate digestives since 1925. 38 00:02:50,240 --> 00:02:53,000 The process begins with the delivery of flour, 39 00:02:53,000 --> 00:02:55,800 just as it has for the past 92 years. 40 00:02:58,120 --> 00:03:00,520 Head of intake is Mike Kiley. 41 00:03:02,200 --> 00:03:04,480 Chocolate biscuits start here, do they? 42 00:03:04,480 --> 00:03:06,840 Yes, they do. How much flour in there? 43 00:03:06,840 --> 00:03:08,880 28 tonne. 28 tonnes? 44 00:03:10,000 --> 00:03:12,120 And how often does a truck of flour turn up? 45 00:03:12,120 --> 00:03:16,080 Seven to eight times a day. A day? Yep. Not a week? No, a day. 46 00:03:16,080 --> 00:03:19,120 Shall we get this thing unloaded? Yeah. All right, buddy. 47 00:03:21,280 --> 00:03:23,480 What's that, mate? This is a control switch for... 48 00:03:23,480 --> 00:03:25,840 Are you going to let me do it? You can have a go. 49 00:03:25,840 --> 00:03:27,840 You need to press the green button, 50 00:03:27,840 --> 00:03:31,400 take your finger off that and press the yellow button for up. 51 00:03:31,400 --> 00:03:35,680 So, green button... Green button and now the yellow button, below it. 52 00:03:35,680 --> 00:03:38,680 Wahey! Wahey! You've got lift-off. 53 00:03:38,680 --> 00:03:41,600 'That gives me a great sense of power. 54 00:03:41,600 --> 00:03:45,600 'Hydraulics jack the front of the tanker eight metres into the air.' 55 00:03:45,600 --> 00:03:48,120 That's a beast of a machine, innit? Yeah, yeah. 56 00:03:49,200 --> 00:03:51,640 So, I'm now moving 28 tonnes of flour? 57 00:03:51,640 --> 00:03:54,720 Yeah. That might be the biggest thing I've ever moved. 58 00:03:56,640 --> 00:03:58,600 'Gravity does all the hard work 59 00:03:58,600 --> 00:04:01,920 'and the flour falls down towards the back. 60 00:04:01,920 --> 00:04:05,560 'A quick pat of the tank confirms there's no trapped air.' 61 00:04:05,560 --> 00:04:07,360 Yeah, you can stop now. 62 00:04:07,360 --> 00:04:10,040 There's plenty of flour at the back of the tank now. 63 00:04:10,040 --> 00:04:13,960 'Which means we can now blow it through into the factory.' 64 00:04:13,960 --> 00:04:17,400 Push your lever down. That'll allow the flour to travel. 65 00:04:17,400 --> 00:04:19,320 Go for it. With all your might. 66 00:04:20,880 --> 00:04:23,760 'Our biscuit production line begins.' 67 00:04:23,760 --> 00:04:24,960 Yes! 68 00:04:24,960 --> 00:04:27,960 'A pneumatic pump pushes the flour out of the tanker 69 00:04:27,960 --> 00:04:31,720 'and into a 40-tonne silo in ingredients intake.' 70 00:04:31,720 --> 00:04:34,240 How long is that going to take to unload? 71 00:04:34,240 --> 00:04:36,520 That's going to take about an hour and 15 minutes. 72 00:04:36,520 --> 00:04:38,680 All right, we'll leave you to it. Thank you very much. 73 00:04:38,680 --> 00:04:41,320 Shall we go to the office? Can I see the next stage? Yeah. 74 00:04:41,320 --> 00:04:43,000 Cheers, mate. Thank you very much. 75 00:04:44,080 --> 00:04:47,520 I'm heading upstairs to the nerve centre of the factory. 76 00:04:51,200 --> 00:04:54,760 Wow! Looks a little bit like the NASA command centre. 77 00:04:57,560 --> 00:05:01,960 These computers monitor the colossal stocks of ingredients. 78 00:05:03,920 --> 00:05:07,920 Is each one of these an actual silo? 79 00:05:07,920 --> 00:05:10,320 Yes. The biggest one is the flour, right? 80 00:05:10,320 --> 00:05:12,440 Yeah, which is 390 tonnes. 81 00:05:12,440 --> 00:05:14,480 Right. And that will last you how long? 82 00:05:14,480 --> 00:05:18,040 Two days. That's only two days' worth of biscuits? Yeah. 83 00:05:20,520 --> 00:05:22,440 Every 24 hours, 84 00:05:22,440 --> 00:05:27,000 20 trucks arrive with ingredients from right across the country. 85 00:05:27,000 --> 00:05:30,440 For my digestives, I'm going to need oil, sugar, 86 00:05:30,440 --> 00:05:33,600 glucose, salt and syrups. 87 00:05:33,600 --> 00:05:37,720 How do you know how much you have to order for the next day? 88 00:05:37,720 --> 00:05:39,360 We don't order. 89 00:05:39,360 --> 00:05:43,160 What happens, then? Each one of our suppliers has access 90 00:05:43,160 --> 00:05:47,680 to see what's inside the tanks, and when they've got an empty tank, 91 00:05:47,680 --> 00:05:50,880 they're sending a delivery. I think that's a brilliant system. 92 00:05:50,880 --> 00:05:53,800 It's like having a little camera inside your cupboard saying, 93 00:05:53,800 --> 00:05:55,960 "We've run out of biscuits..." Get some more! 94 00:05:55,960 --> 00:05:58,080 And the supermarket sends the biscuits along! 95 00:05:58,080 --> 00:05:59,680 Yeah. Is that right? Very true. 96 00:06:02,080 --> 00:06:05,480 An hour and a quarter after it arrived, my flour is unloaded. 97 00:06:06,440 --> 00:06:08,280 The computer screens confirm 98 00:06:08,280 --> 00:06:10,840 that everything else is ready and waiting. 99 00:06:12,720 --> 00:06:16,040 I've now got nearly all of my ingredients for my biscuit. 100 00:06:16,040 --> 00:06:19,200 However, Cherry, where's my chocolate? 101 00:06:22,640 --> 00:06:27,400 It's being prepared 200 miles away at this refinery in Manchester. 102 00:06:31,480 --> 00:06:34,880 I'm going to make a batch of chocolate for Gregg's biscuits 103 00:06:34,880 --> 00:06:36,760 with factory manager, Dee Smith. 104 00:06:37,880 --> 00:06:39,880 Hi, Dee! Hi, Cherry. 105 00:06:39,880 --> 00:06:42,920 Lovely to meet you! Welcome to Manchester. Thank you so much! 106 00:06:43,920 --> 00:06:46,640 So, this is where you cook the chocolate? 107 00:06:46,640 --> 00:06:49,240 Well, this is where we make the chocolate. 108 00:06:49,240 --> 00:06:50,720 There's no cooking involved. 109 00:06:50,720 --> 00:06:53,640 So, it's a process of mixing, refining, 110 00:06:53,640 --> 00:06:56,080 and a very special process called conching. 111 00:06:56,080 --> 00:06:58,440 But this is no ordinary chocolate. 112 00:06:58,440 --> 00:07:01,920 No, it's a really special chocolate for coating biscuits, 113 00:07:01,920 --> 00:07:04,160 so that when you put it in your mouth, it melts. 114 00:07:07,920 --> 00:07:11,600 So, we've got 1,500 kilos of mix in here. 115 00:07:11,600 --> 00:07:13,920 And it's just about ready to discharge. 116 00:07:13,920 --> 00:07:16,560 Oh, here we go! Are we ready? Something's happening! 117 00:07:16,560 --> 00:07:17,760 Oh! 118 00:07:17,760 --> 00:07:19,800 Right, let's have a peek. Whoa! 119 00:07:19,800 --> 00:07:22,040 SHE YELPS Wow! 120 00:07:22,040 --> 00:07:25,240 It's so... Look at that! SHE LAUGHS 121 00:07:26,640 --> 00:07:29,640 'This is a rough mix of cocoa, sugar, 122 00:07:29,640 --> 00:07:32,280 'milk powder, oil and vanilla.' 123 00:07:32,280 --> 00:07:33,440 It doesn't feel like 124 00:07:33,440 --> 00:07:36,080 it's sticking your hands into chocolate, that's for sure. 125 00:07:36,080 --> 00:07:38,880 It does remind me of something else, I'll be honest! 126 00:07:38,880 --> 00:07:42,360 It's very granulated at this stage. It's quite rough. 127 00:07:43,760 --> 00:07:47,720 Dee, that is one of the most beautiful smells on Planet Earth, 128 00:07:47,720 --> 00:07:50,000 but I've got to say... Smells better than it looks! 129 00:07:50,000 --> 00:07:52,000 ..it smells better than it looks! 130 00:07:52,000 --> 00:07:54,000 Can I taste it? Yes, you can. 131 00:07:58,120 --> 00:08:00,680 It tastes like chocolate sand. 132 00:08:00,680 --> 00:08:03,080 That's a really good description, actually. 133 00:08:03,080 --> 00:08:05,160 And that's why we need to get the particle size 134 00:08:05,160 --> 00:08:06,760 much, much, much smaller. 135 00:08:08,640 --> 00:08:12,680 The sugar crystals are currently the size of the granulated sugar 136 00:08:12,680 --> 00:08:14,440 you buy in the shops. 137 00:08:14,440 --> 00:08:16,840 To make the mix smoother, 138 00:08:16,840 --> 00:08:20,920 it's dropped down 16 feet, into machines called refiners. 139 00:08:22,600 --> 00:08:26,560 This is the first stage of the refining process. 140 00:08:26,560 --> 00:08:30,360 Here, the grainy mix is crushed by a series of giant rollers 141 00:08:30,360 --> 00:08:32,000 into tiny flakes. 142 00:08:32,000 --> 00:08:35,400 And it reduces the particle size down from 1.5mm 143 00:08:35,400 --> 00:08:40,600 that we saw upstairs, down to 0.05 of a millimetre. 144 00:08:40,600 --> 00:08:44,040 That actually increases the surface area and therefore, 145 00:08:44,040 --> 00:08:47,760 it goes from becoming like a slurry and into a powder. 146 00:08:47,760 --> 00:08:50,640 The next process, called conching, 147 00:08:50,640 --> 00:08:54,800 will transform the dry powder into molten chocolate. 148 00:08:57,360 --> 00:09:00,120 OK, Cherry, this is conching. 149 00:09:00,120 --> 00:09:03,600 It is Willy Wonka! Yes! 150 00:09:03,600 --> 00:09:07,040 In here, there's six tonnes of chocolate 151 00:09:07,040 --> 00:09:09,720 and it gets mixed for six hours. 152 00:09:09,720 --> 00:09:14,120 With huge blades, almost like a Mississippi riverboat! 153 00:09:14,120 --> 00:09:17,320 Absolutely, but it's much more aggressive than that. 154 00:09:19,720 --> 00:09:23,280 Liquid cocoa butter has been added to help the chocolate 155 00:09:23,280 --> 00:09:25,640 spread evenly on top of our biscuits. 156 00:09:27,120 --> 00:09:29,640 Astonishingly, the chemistry of this process 157 00:09:29,640 --> 00:09:31,600 is still not fully understood. 158 00:09:33,120 --> 00:09:35,200 But it makes a big difference. 159 00:09:35,200 --> 00:09:38,520 The endless churning releases flavour compounds, 160 00:09:38,520 --> 00:09:41,600 making the chocolate taste rich and velvety. 161 00:09:43,760 --> 00:09:46,760 # Oh, yeah! # 162 00:09:46,760 --> 00:09:50,480 But if you beat it for too long, you get a flavour that's different. 163 00:09:50,480 --> 00:09:53,520 And that's one of the signatures of our chocolate, 164 00:09:53,520 --> 00:09:56,920 is mixing it just right to get that correct flavour 165 00:09:56,920 --> 00:09:59,440 and the correct thickness of the chocolate. 166 00:10:00,600 --> 00:10:02,120 # Beautiful! # 167 00:10:04,120 --> 00:10:08,360 After six hours, my chocolate is shiny and smooth. 168 00:10:09,920 --> 00:10:11,600 But it's not going anywhere 169 00:10:11,600 --> 00:10:16,000 until it's been thoroughly tested by refinery veterans Carla and Eva. 170 00:10:17,560 --> 00:10:20,800 Using a technique called laser diffraction, 171 00:10:20,800 --> 00:10:24,040 they fire laser beams at the particles in the chocolate 172 00:10:24,040 --> 00:10:25,760 to check they're the right size. 173 00:10:26,920 --> 00:10:29,400 But the machine doesn't get final approval. 174 00:10:29,400 --> 00:10:33,160 Carla and Eva have to conduct a chocolate taste test 175 00:10:33,160 --> 00:10:34,760 to check its consistency. 176 00:10:35,840 --> 00:10:38,360 So, what are you looking for when you test chocolate? 177 00:10:38,360 --> 00:10:40,040 Yes, we have to test the viscosity, 178 00:10:40,040 --> 00:10:43,680 so that you know that it's going to coat the biscuit correctly. 179 00:10:43,680 --> 00:10:46,560 And hold the shape of the design on the top. 180 00:10:46,560 --> 00:10:48,400 There we go. 181 00:10:48,400 --> 00:10:50,840 Oh, fresh out the conch. 182 00:10:50,840 --> 00:10:54,200 Just dip it in and try and put it in the middle of your tongue. 183 00:10:54,200 --> 00:10:56,960 OK. And leave it there. SHE CHUCKLES 184 00:11:02,000 --> 00:11:07,720 That is just the most gorgeously sweet and rich and smooth chocolate. 185 00:11:07,720 --> 00:11:11,040 So, all that sugar has been refined. 186 00:11:11,040 --> 00:11:12,840 Are you not sick of chocolate? 187 00:11:12,840 --> 00:11:15,200 I'm not sick of chocolate, but I can never go to a party 188 00:11:15,200 --> 00:11:16,920 because if I see a chocolate fountain, 189 00:11:16,920 --> 00:11:18,440 it just reminds me of work. 190 00:11:19,720 --> 00:11:23,880 So, no fondue and no chocolate fountains, thank you very much. 191 00:11:28,920 --> 00:11:33,600 Now, my chocolate's ready for its 200-mile journey to London. 192 00:11:33,600 --> 00:11:36,200 To make sure it doesn't solidify in transit, 193 00:11:36,200 --> 00:11:38,960 it's pumped into a specially heated tanker. 194 00:11:40,040 --> 00:11:43,120 The lorry is specifically designed to ensure 195 00:11:43,120 --> 00:11:45,960 that the temperature's kept at 50 degrees centigrade 196 00:11:45,960 --> 00:11:47,440 for the entire journey. 197 00:11:47,440 --> 00:11:51,120 So, is the lorry like a huge hot thermos of chocolate? 198 00:11:52,560 --> 00:11:55,760 How much is the chocolate in this lorry worth? 199 00:11:55,760 --> 00:11:59,520 About £50,000 worth of chocolate in a tanker like this. 200 00:11:59,520 --> 00:12:02,040 Liquid gold. Yeah, absolutely. 201 00:12:03,120 --> 00:12:08,160 26 tonnes of liquid chocolate heads out on its way to the factory. 202 00:12:08,160 --> 00:12:12,960 Just one of 14 trucks making this four-hour journey every week. 203 00:12:16,800 --> 00:12:18,680 And after a trouble-free trip, 204 00:12:18,680 --> 00:12:22,200 it's ready and waiting for me in the wet ingredients area. 205 00:12:24,080 --> 00:12:27,480 Factory manager Nina Sparks is showing me round. 206 00:12:27,480 --> 00:12:30,800 Nina, this is big. 207 00:12:30,800 --> 00:12:33,400 This is, and this is where the chocolate 208 00:12:33,400 --> 00:12:36,400 comes into the liquids block. 209 00:12:36,400 --> 00:12:38,040 So, it's a big pump here, 210 00:12:38,040 --> 00:12:40,040 chocolate's connected up on the outside 211 00:12:40,040 --> 00:12:43,040 and it's pumped into one of these six tanks. 212 00:12:43,040 --> 00:12:47,000 How much chocolate? Each tank's probably got about 26 tonnes in. 213 00:12:47,000 --> 00:12:50,920 We can hold about 160 tonnes at any one time. 214 00:12:51,960 --> 00:12:55,560 Chocolate is the most expensive ingredient needed for my biscuits. 215 00:12:55,560 --> 00:12:58,600 It costs around £2,000 a tonne, 216 00:12:58,600 --> 00:13:01,800 so Nina and I are currently surrounded 217 00:13:01,800 --> 00:13:06,000 by about £320,000 worth of the stuff. 218 00:13:06,000 --> 00:13:08,040 I can show you the top of one, if you want to. 219 00:13:08,040 --> 00:13:09,800 I can look into a tank of chocolate? 220 00:13:09,800 --> 00:13:12,000 You can come and see 26 tonne of chocolate, Come on. 221 00:13:12,000 --> 00:13:13,960 Has anyone ever sort of paddled in it? No! 222 00:13:13,960 --> 00:13:15,640 Can I dunk in it, just up to my knee? 223 00:13:15,640 --> 00:13:17,200 No, you can't. No? Are you sure? 224 00:13:18,880 --> 00:13:21,600 Each silo is 12 metres tall 225 00:13:21,600 --> 00:13:25,800 and kept at a constant temperature of 55 degrees Celsius 226 00:13:25,800 --> 00:13:28,560 to ensure the chocolate stays liquid. 227 00:13:28,560 --> 00:13:30,320 You can't just heat it back up again? 228 00:13:30,320 --> 00:13:31,880 It would take a really long time. 229 00:13:31,880 --> 00:13:34,200 Once chocolate goes hard, it takes a lot of energy, 230 00:13:34,200 --> 00:13:36,560 a lot of heat, to get it back to being liquid again. 231 00:13:36,560 --> 00:13:37,960 Do you want to have a look in? 232 00:13:42,800 --> 00:13:44,120 Wow! 233 00:13:45,680 --> 00:13:48,720 Yep! That's where I want to go. 234 00:13:48,720 --> 00:13:52,760 Can't I just get a ladle of it out? No. Why? Why can't I? 235 00:13:52,760 --> 00:13:53,920 I'm not coming out! 236 00:13:54,920 --> 00:13:56,400 I like it in here. 237 00:13:58,040 --> 00:13:59,880 In the next 24 hours, 238 00:13:59,880 --> 00:14:03,800 they'll get through over two silos' worth of liquid chocolate. 239 00:14:05,160 --> 00:14:08,800 Right, got the dry ingredients, now I've got my chocolate. 240 00:14:08,800 --> 00:14:11,600 Can I go and make some biscuits? Let's go. Come on! 241 00:14:12,920 --> 00:14:15,880 I'm going to be one of the best biscuit-makers you've ever seen. 242 00:14:15,880 --> 00:14:16,960 You are! 243 00:14:18,000 --> 00:14:20,000 Next door is the mixing hall. 244 00:14:21,960 --> 00:14:24,400 Here, I'm going to make my batch of dough. 245 00:14:25,800 --> 00:14:30,240 It's a two-stage process, and the first is called creaming up. 246 00:14:31,320 --> 00:14:32,800 We've got 11 mixers up here 247 00:14:32,800 --> 00:14:34,920 and this mixer here is the one we're going to make 248 00:14:34,920 --> 00:14:37,440 your batch of biscuits on. Are they waiting for this now? 249 00:14:37,440 --> 00:14:40,200 They are waiting for us. We've got to get on. Seriously? 250 00:14:40,200 --> 00:14:41,880 We need to go and start the mixer. 251 00:14:41,880 --> 00:14:43,920 I need you to press that green button now. 252 00:14:43,920 --> 00:14:46,920 Is that all? Just the green button. And that's going to make it start? 253 00:14:46,920 --> 00:14:49,000 Don't mess it up, Gregg, just the green button. 254 00:14:49,000 --> 00:14:50,760 You want to start this, don't you? I do. 255 00:14:52,680 --> 00:14:55,040 It's just started its process and it will be dropping 256 00:14:55,040 --> 00:14:58,280 all the different ingredients it needs into the bowl right now. 257 00:15:00,400 --> 00:15:04,360 The wet ingredients - fat, water and sugars - 258 00:15:04,360 --> 00:15:08,440 are dropped into the hopper and mixed together for 90 seconds. 259 00:15:15,680 --> 00:15:19,240 That is just like a great big mixing bowl, isn't it? 260 00:15:19,240 --> 00:15:21,240 Same as the bowl at home. Exactly. 261 00:15:21,240 --> 00:15:23,760 Do you know how many biscuits that will make? 262 00:15:23,760 --> 00:15:27,520 60,000. 60,000 in each batch? That's right, yeah. 263 00:15:27,520 --> 00:15:30,160 That's fantastic. Right, now what happens to it? 264 00:15:30,160 --> 00:15:32,640 Right, so, now we're ready to do our dough-up. 265 00:15:32,640 --> 00:15:35,040 You honestly call it a dough-up? We do. 266 00:15:35,040 --> 00:15:37,960 This is where we add our flours, so we've got white flour, 267 00:15:37,960 --> 00:15:39,760 wholemeal flour and a touch of salt. 268 00:15:40,800 --> 00:15:42,640 Cream-up, dough-up? Correct. 269 00:15:42,640 --> 00:15:44,760 Do you get a biscuit-up, eventually? 270 00:15:44,760 --> 00:15:46,320 Well, we hope so, yeah. 271 00:15:49,960 --> 00:15:53,920 'My flour, along with the other dry ingredients, drops down from above. 272 00:15:55,800 --> 00:15:59,720 'Another 17 minutes of mixing and my dough is done.' 273 00:15:59,720 --> 00:16:01,480 Whay! Yay! 274 00:16:01,480 --> 00:16:04,280 Now, that looks like a biscuit batch. That's right. 275 00:16:04,280 --> 00:16:06,240 So, we've got to do some checks on it first, 276 00:16:06,240 --> 00:16:08,200 so if you open the door for me. 277 00:16:08,200 --> 00:16:09,640 Right. 278 00:16:09,640 --> 00:16:11,960 Can you put the thermometer in it, please, Gregg? 279 00:16:11,960 --> 00:16:14,480 Why? Because if it's too cold, 280 00:16:14,480 --> 00:16:16,200 then the dough will be too crumbly 281 00:16:16,200 --> 00:16:18,000 and we won't be able to form a biscuit. 282 00:16:18,000 --> 00:16:19,360 And if it's too hot, 283 00:16:19,360 --> 00:16:22,720 it'll be too sticky and it will not run through our equipment. 284 00:16:22,720 --> 00:16:26,320 What temperature do you want? I want it to be between 24 and 28. 285 00:16:26,320 --> 00:16:28,200 What is it? 26. 286 00:16:28,200 --> 00:16:29,400 Perfect, right. 287 00:16:32,040 --> 00:16:35,680 I've now got 850 kilos of dough 288 00:16:35,680 --> 00:16:38,320 ready to turn into digestive biscuits. 289 00:16:40,080 --> 00:16:43,880 Digestive - that's quite an odd name for a biscuit, isn't it? 290 00:16:43,880 --> 00:16:46,160 Ruth has been checking out its origin. 291 00:16:50,120 --> 00:16:53,680 We all know these instantly as digestive biscuits, 292 00:16:53,680 --> 00:16:55,440 but I'm not sure that my doctor 293 00:16:55,440 --> 00:16:58,680 is going to be prescribing them any time soon. 294 00:16:58,680 --> 00:17:03,560 So, where did this association with digestion come from? 295 00:17:05,480 --> 00:17:08,960 'Medical historian Professor Louise Hill Curth...' 296 00:17:08,960 --> 00:17:10,720 Ruth! Good to see you! 297 00:17:10,720 --> 00:17:12,520 '..tells me that 500 years ago, 298 00:17:12,520 --> 00:17:14,560 'biscuits were thought of as medicine 299 00:17:14,560 --> 00:17:16,760 'and given to people who were ill.' 300 00:17:16,760 --> 00:17:20,760 So, today, you might be given something really bland 301 00:17:20,760 --> 00:17:22,720 and easy to digest. 302 00:17:22,720 --> 00:17:26,720 Well, in the Tudor period, you might be given biscuits. 303 00:17:26,720 --> 00:17:29,120 Because they were very easy to digest. 304 00:17:29,120 --> 00:17:32,680 They were very light, there wasn't much in them, 305 00:17:32,680 --> 00:17:36,160 and you could have those as part of your recuperation. 306 00:17:36,160 --> 00:17:38,760 So, have we got any sort of references 307 00:17:38,760 --> 00:17:41,400 to people eating biscuits for their health? 308 00:17:41,400 --> 00:17:43,200 Lots. Lots and lots. 309 00:17:44,320 --> 00:17:47,640 'One of them is from the mid-17th-century diarist 310 00:17:47,640 --> 00:17:52,400 'Samuel Pepys, in his entry for September 1665.' 311 00:17:53,480 --> 00:17:56,360 "Being full of wind and out of order, 312 00:17:56,360 --> 00:17:58,120 "and there called for a biscuit." 313 00:17:59,640 --> 00:18:01,640 "My digestion's all up the Swanee and..." 314 00:18:01,640 --> 00:18:03,840 Well, wouldn't you? "I need biscuits!" 315 00:18:03,840 --> 00:18:05,440 Yeah! "Bring me a biscuit!" 316 00:18:05,440 --> 00:18:10,840 And a play from 1662 promoted the medicinal properties 317 00:18:10,840 --> 00:18:14,080 of something called a Naples biscuit. 318 00:18:14,080 --> 00:18:16,960 And in the afternoon, about four or five o'clock, 319 00:18:16,960 --> 00:18:20,440 you must take "Naples biscuit dipped in Hippocras..." 320 00:18:20,440 --> 00:18:24,160 Which is wine. "..which helps digestion much." 321 00:18:25,160 --> 00:18:29,240 That's right, so, you dip it in wine and that helps your digestion. 322 00:18:29,240 --> 00:18:31,960 'These Naples biscuits were quite different 323 00:18:31,960 --> 00:18:34,680 'from the digestives we know today.' 324 00:18:34,680 --> 00:18:38,000 We've got a 17th-century recipe here. Absolutely. 325 00:18:38,000 --> 00:18:41,440 'The ingredients were exotic and expensive.' 326 00:18:41,440 --> 00:18:44,280 Take almonds, beaten very fine. 327 00:18:44,280 --> 00:18:47,560 Was that important, then, the fineness of the almond? 328 00:18:47,560 --> 00:18:50,560 Absolutely. Because you want it really easy to digest, 329 00:18:50,560 --> 00:18:52,880 so you don't want big pieces of something. 330 00:18:55,120 --> 00:18:57,880 We're now going to add wine, OK? 331 00:18:57,880 --> 00:19:01,000 As much as we need to. Medicinal. Absolutely. 332 00:19:01,000 --> 00:19:03,960 You feel much better, don't you? I'm feeling better already. 333 00:19:03,960 --> 00:19:05,480 I knew you would. 334 00:19:05,480 --> 00:19:08,160 'Next, we add fine flour and rose water, 335 00:19:08,160 --> 00:19:10,840 'which was meant to be good for the heart.' 336 00:19:10,840 --> 00:19:15,160 The next thing we're going to put in is an entire pound of sugar. 337 00:19:15,160 --> 00:19:17,080 I mean, this is a health recipe! 338 00:19:17,080 --> 00:19:20,080 It's packed full of alcohol and sugar! Well, yes. 339 00:19:21,200 --> 00:19:23,600 'The final ingredient is whipped-up egg white, 340 00:19:23,600 --> 00:19:25,280 'which helps to aerate the mix.' 341 00:19:26,280 --> 00:19:27,920 According to the original recipes, 342 00:19:27,920 --> 00:19:31,200 we need to now put them into tin coffins. 343 00:19:31,200 --> 00:19:34,400 I love that word. It's the word for any pastry case at that period. 344 00:19:34,400 --> 00:19:37,200 That's right. Have you got any tin coffins? 345 00:19:37,200 --> 00:19:41,280 We don't have any, unfortunately, but we do have the next best thing. 346 00:19:45,000 --> 00:19:48,400 'After baking, it's time to give the Naples biscuits a try.' 347 00:19:51,320 --> 00:19:53,560 Mmm. SHE LAUGHS 348 00:19:53,560 --> 00:19:55,760 They are quite unique. Certainly very different 349 00:19:55,760 --> 00:19:58,520 from the sort of biscuit we would call a digestive these days. 350 00:19:58,520 --> 00:20:00,720 They're very light, aren't they? They are. Yeah. 351 00:20:00,720 --> 00:20:02,120 Do you feel healthier? 352 00:20:04,520 --> 00:20:08,160 It was another 200 years before the modern digestive appeared. 353 00:20:09,600 --> 00:20:12,800 This 1829 advert in the Manchester Courier 354 00:20:12,800 --> 00:20:14,920 is one of the earliest known references 355 00:20:14,920 --> 00:20:16,560 to a biscuit with that name. 356 00:20:16,560 --> 00:20:18,560 And it says, "J Hutchinson, 357 00:20:18,560 --> 00:20:22,960 "the original introducer and sole proprietor of Abernethy's 358 00:20:22,960 --> 00:20:25,560 "celebrated digestive biscuits..." 359 00:20:25,560 --> 00:20:28,520 'Made to a similar recipe to the version we know today, 360 00:20:28,520 --> 00:20:31,720 'they were still being marketed as a health product.' 361 00:20:31,720 --> 00:20:35,640 The number of things this claims to cure is quite remarkable! 362 00:20:35,640 --> 00:20:38,800 Imagine being able to cure typhoid or scarlet fever 363 00:20:38,800 --> 00:20:40,600 by eating a biscuit! 364 00:20:40,600 --> 00:20:42,520 I mean, this is ridiculous, isn't it? 365 00:20:42,520 --> 00:20:44,560 Er, by modern standards, yeah, 366 00:20:44,560 --> 00:20:47,280 but it is very typical of the 19th century. 367 00:20:48,560 --> 00:20:51,920 When McVitie's introduced their version in 1892, 368 00:20:51,920 --> 00:20:54,680 the focus was more on the taste of the biscuit, 369 00:20:54,680 --> 00:20:57,440 rather than its perceived health benefits. 370 00:20:57,440 --> 00:21:00,680 But the name - digestive - remained. 371 00:21:06,480 --> 00:21:07,920 GREGG: An hour and a half in, 372 00:21:07,920 --> 00:21:12,640 I'm gearing up to make a super-sized batch of 60,000 biscuits. 373 00:21:13,640 --> 00:21:15,560 My dough has made it to the oven hall, 374 00:21:15,560 --> 00:21:17,840 where I'm meeting Lawrence Gathari. 375 00:21:17,840 --> 00:21:20,440 He's worked here for 38 years... 376 00:21:20,440 --> 00:21:22,960 Hello, Gregg! Hello, mate. 377 00:21:22,960 --> 00:21:25,400 ..and knows biscuits inside out. 378 00:21:26,640 --> 00:21:28,680 Right, I'm ready to make biscuits. 379 00:21:28,680 --> 00:21:30,520 What happens down here? 380 00:21:30,520 --> 00:21:34,160 Well, down here is the area where we mould the biscuits. 381 00:21:34,160 --> 00:21:35,640 Why do you keep looking up there? 382 00:21:35,640 --> 00:21:37,720 Because in a minute, I want you to get up there 383 00:21:37,720 --> 00:21:40,560 and tell me what you see. Really? Yes. Up? 384 00:21:41,880 --> 00:21:44,560 If I'm not back, tell me mum I love her. OK, I will. 385 00:21:47,040 --> 00:21:49,120 It's not what I expected. 386 00:21:49,120 --> 00:21:51,440 It's coming down in great clumps, 387 00:21:51,440 --> 00:21:55,560 pretty much like the way snow falls off the roof of your shed, you know? 388 00:21:55,560 --> 00:21:59,240 Well, it's the type of dough that's easily broken up. 389 00:21:59,240 --> 00:22:02,440 There's quite a loose consistency to the dough. 390 00:22:02,440 --> 00:22:06,200 So what we need to do is break it up into small enough clumps, 391 00:22:06,200 --> 00:22:09,600 so it can be evenly distributed into the small hopper. 392 00:22:13,040 --> 00:22:16,040 'The machine that does this is called the kibbler. 393 00:22:19,080 --> 00:22:23,760 'Spinning blades shred the dough and fling the pieces onto a conveyor. 394 00:22:23,760 --> 00:22:27,920 'They are now only moments away from their biscuit-shaped destiny.' 395 00:22:27,920 --> 00:22:30,760 I can see the dough's coming down there. 396 00:22:30,760 --> 00:22:33,520 It's then dropping between two rollers. 397 00:22:33,520 --> 00:22:35,760 The front roller that you can see there 398 00:22:35,760 --> 00:22:37,720 is what we call the moulding roller, 399 00:22:37,720 --> 00:22:40,760 which has the shape of the biscuit cut in silhouette. 400 00:22:40,760 --> 00:22:45,040 I can see this mould shining in a little bit of light. 401 00:22:45,040 --> 00:22:47,920 Can I get a closer look at that? Well, we've got one over there. 402 00:22:47,920 --> 00:22:49,920 Shall we go and see it? Yeah, yeah, yeah. 403 00:22:51,400 --> 00:22:53,440 That is a beautiful thing! 404 00:22:55,360 --> 00:22:57,680 I can see exactly how that works now. 405 00:22:57,680 --> 00:23:00,960 As that turns, the dough is pushed onto it 406 00:23:00,960 --> 00:23:03,000 and that then is cutting the shape 407 00:23:03,000 --> 00:23:05,280 and it's imprinting the name and the holes. 408 00:23:05,280 --> 00:23:07,120 Absolutely right. Well done. 409 00:23:07,120 --> 00:23:09,120 It's very attractive and rather clever. 410 00:23:09,120 --> 00:23:11,360 Not unlike yourself, mate. Thank you, Gregg. 411 00:23:28,360 --> 00:23:31,520 I'm surprised that you mould these biscuits and don't cut them. 412 00:23:31,520 --> 00:23:34,560 At home, you would have a big sheet of pastry 413 00:23:34,560 --> 00:23:37,880 and you would cut each biscuit from it. 414 00:23:37,880 --> 00:23:40,680 Well, here, Gregg, we're making so many biscuits, 415 00:23:40,680 --> 00:23:43,600 this is the only way that we can mass-produce them. 416 00:23:43,600 --> 00:23:47,640 Do you know how many biscuits are passing our nose every minute? 417 00:23:47,640 --> 00:23:49,680 Over 3,000. Is it? 418 00:23:51,280 --> 00:23:53,080 THEY CACKLE 419 00:23:54,480 --> 00:23:57,400 This factory runs 24 hours a day, 420 00:23:57,400 --> 00:24:00,400 stamping out a never-ending river of biscuits. 421 00:24:01,640 --> 00:24:04,400 At this rate, it'll take less than 20 minutes 422 00:24:04,400 --> 00:24:07,120 to mould my batch of 60,000. 423 00:24:07,120 --> 00:24:09,960 What happens to all the little extra bits? 424 00:24:09,960 --> 00:24:13,520 There's a scraper that scrapes the excess dough off them 425 00:24:13,520 --> 00:24:16,240 and it drops into this conveyor by my feet 426 00:24:16,240 --> 00:24:19,640 and it runs into this spiral and fed back in. 427 00:24:21,080 --> 00:24:23,080 Hang on. Things go down a spiral. 428 00:24:23,080 --> 00:24:25,200 These look like they're going up a spiral. 429 00:24:25,200 --> 00:24:26,720 They're designed in a way 430 00:24:26,720 --> 00:24:30,040 that it vibrates to send the product upwards. 431 00:24:30,040 --> 00:24:31,880 That's defying gravity! 432 00:24:31,880 --> 00:24:34,120 There you go, Things don't go up a spiral! 433 00:24:34,120 --> 00:24:35,800 It's amazing what you can do here. 434 00:24:42,480 --> 00:24:47,600 So, obviously, this roller is a crucial bit of biscuit-making kit. 435 00:24:47,600 --> 00:24:52,240 Chances are, this one started life in Wigan, with a man called Alan. 436 00:24:52,240 --> 00:24:54,080 Cherry went to meet him. 437 00:24:54,080 --> 00:24:57,360 Hi, excuse me. I'm looking for Alan. 438 00:24:58,280 --> 00:25:00,240 Alan Long? Yeah. He's in unit 5A. 439 00:25:08,440 --> 00:25:10,440 Hi, Alan! Hello, Cherry. 440 00:25:10,440 --> 00:25:12,400 Nice to meet you. Nice to meet you. 441 00:25:12,400 --> 00:25:14,160 'Alan Long creates the rollers 442 00:25:14,160 --> 00:25:16,840 'used in most of Britain's biscuit factories.' 443 00:25:16,840 --> 00:25:19,400 Where is everybody? 444 00:25:19,400 --> 00:25:22,760 There's just me. Everything here, I do. 445 00:25:22,760 --> 00:25:24,240 So, where do we start? 446 00:25:24,240 --> 00:25:25,680 We're going to get a blank roller 447 00:25:25,680 --> 00:25:27,800 and we're going to turn it into a biscuit roller. 448 00:25:27,800 --> 00:25:29,280 All right, let's get cracking. 449 00:25:30,240 --> 00:25:32,640 His one-man manufacturing process 450 00:25:32,640 --> 00:25:35,200 begins with a shiny roller of bronze. 451 00:25:35,200 --> 00:25:40,480 It weighs 400 kilos and costs up to £5,000. 452 00:25:40,480 --> 00:25:43,760 Bronze has been the alloy of choice for artists and sculptors 453 00:25:43,760 --> 00:25:47,760 for millennia, and it turns out it's a favourite of Alan's too. 454 00:25:49,120 --> 00:25:53,280 Why on earth do you use such a luxurious material? 455 00:25:53,280 --> 00:25:55,400 Well, the great thing about the bronze 456 00:25:55,400 --> 00:25:58,920 is it's food-approved, lead-free and also it's very nice to machine. 457 00:25:58,920 --> 00:26:02,080 I really love that this is how biscuits start their life. 458 00:26:02,080 --> 00:26:03,960 It's a thing of beauty. 459 00:26:03,960 --> 00:26:07,040 At the moment. We're going to make it look even more beautiful. 460 00:26:07,040 --> 00:26:10,920 'Today, Alan's making a mould for shortbread biscuits.' 461 00:26:10,920 --> 00:26:13,200 Up? Yes, please. Up is up? 462 00:26:13,200 --> 00:26:17,520 'And my first job is to help winch the bronze roller 463 00:26:17,520 --> 00:26:19,680 'into the specialist milling machine.' 464 00:26:19,680 --> 00:26:21,200 Down, down, down. 465 00:26:24,320 --> 00:26:26,120 Is that right? Yeah, perfect. 466 00:26:26,120 --> 00:26:28,640 Who knew this is how biscuits start? 467 00:26:29,680 --> 00:26:31,560 'To avoid wonky biscuits, 468 00:26:31,560 --> 00:26:35,960 'the roller must be perfectly level before the machine starts cutting. 469 00:26:35,960 --> 00:26:39,200 'This measuring tool can detect minute changes 470 00:26:39,200 --> 00:26:40,680 'to the roller's alignment. 471 00:26:40,680 --> 00:26:43,040 'If the needle moves, there's a problem.' 472 00:26:43,040 --> 00:26:46,000 Perfect. It's not moving, is it? Didn't move, did it? It's perfect. 473 00:26:46,000 --> 00:26:49,960 That did not move at all. Nice and flat. It did not move. 474 00:26:49,960 --> 00:26:52,840 This is such an exercise of precision. 475 00:26:52,840 --> 00:26:56,000 There's going to be no uneven biscuits on Alan's watch. 476 00:26:57,840 --> 00:27:00,560 'The roller's in place, and in the office, 477 00:27:00,560 --> 00:27:03,800 'I get to see the shortbread petticoat tail design 478 00:27:03,800 --> 00:27:05,560 'we'll be cutting into it.' 479 00:27:05,560 --> 00:27:08,040 So, that's a mock-up of what will happen? 480 00:27:08,040 --> 00:27:11,360 This is a simulation of what we see on the machine. 481 00:27:11,360 --> 00:27:14,480 The tool will move in that way and cut out 482 00:27:14,480 --> 00:27:17,720 that imprint into the bronze? Exactly that tool path, yeah. 483 00:27:17,720 --> 00:27:20,440 I mean, that is so intricate. 484 00:27:20,440 --> 00:27:23,120 So, how do you design a biscuit? 485 00:27:23,120 --> 00:27:25,400 Everything's drawn up here on this CAD system. 486 00:27:25,400 --> 00:27:29,160 This one, originally, the customer told me he wanted six segments, 487 00:27:29,160 --> 00:27:31,760 as you can see, with a random docker pattern 488 00:27:31,760 --> 00:27:35,120 and a border outline with the little flutes around. 489 00:27:35,120 --> 00:27:37,120 How did you learn to do this? 490 00:27:37,120 --> 00:27:39,320 Originally, I was in the aerospace industry. 491 00:27:39,320 --> 00:27:41,800 I then decided to use that technology 492 00:27:41,800 --> 00:27:45,560 in the biscuit industry to make that a more modern process. 493 00:27:45,560 --> 00:27:48,840 Could you ever have guessed this is what you would end up doing? 494 00:27:48,840 --> 00:27:50,920 Not at the time, no! 495 00:27:50,920 --> 00:27:53,840 'Alan sends the design over to the milling machine 496 00:27:53,840 --> 00:27:55,640 'and prepares a new drillbit.' 497 00:27:56,640 --> 00:27:58,400 OK, Cherry, it's ready to go. 498 00:28:00,240 --> 00:28:02,720 Turn the feed up, it's 100%. 499 00:28:02,720 --> 00:28:06,320 100%? Come on, memory. Memory. Search. 500 00:28:06,320 --> 00:28:09,160 Search. Programme 4. Yes. 501 00:28:09,160 --> 00:28:11,240 Cycle start. Cycle start. Stand by! 502 00:28:16,800 --> 00:28:18,120 Whoa! 503 00:28:21,960 --> 00:28:26,400 This tungsten carbide drill cuts into the bronze. 504 00:28:26,400 --> 00:28:30,760 It's accurate to within 0.03 of a millimetre. 505 00:28:34,720 --> 00:28:37,160 Wow, that looks so cool! 506 00:28:41,880 --> 00:28:46,720 'It can take up to an hour to engrave a single biscuit design.' 507 00:28:49,720 --> 00:28:52,040 Do you want to have a look at it? So badly! 508 00:28:53,080 --> 00:28:55,680 Oh, my goodness! 509 00:28:55,680 --> 00:28:57,880 So, there's your first petticoat tail done. 510 00:28:57,880 --> 00:29:00,640 It's unnecessarily beautiful. It's great, isn't it? 511 00:29:00,640 --> 00:29:03,080 Considering it's just going to imprint a biscuit. 512 00:29:03,080 --> 00:29:05,560 It is, yeah. It's a work of art! Do you like it? 513 00:29:05,560 --> 00:29:08,920 It will go into a machine, it'll make lots and lots of biscuits. 514 00:29:08,920 --> 00:29:12,560 Engraving the 40 moulds wrapped around this roller 515 00:29:12,560 --> 00:29:14,680 will take 40 hours. 516 00:29:14,680 --> 00:29:18,280 Some intricate biscuit patterns, like this custard cream, 517 00:29:18,280 --> 00:29:20,840 can take five days to complete. 518 00:29:22,120 --> 00:29:24,120 I'm going to leave you to it. Right. 519 00:29:24,120 --> 00:29:28,360 But before I go, can I take a souvenir, to see if it works? 520 00:29:28,360 --> 00:29:30,760 Of course you can. Hee-hee-hee! 521 00:29:30,760 --> 00:29:32,320 Here we go, the moment of truth. 522 00:29:33,440 --> 00:29:36,040 Look! That is... 523 00:29:36,040 --> 00:29:38,400 Beautiful. Beautiful. 524 00:29:38,400 --> 00:29:42,040 I love it. Thank you so much. No problem. 525 00:29:42,040 --> 00:29:45,680 'Each finished roller has a lifespan of up to two years, 526 00:29:45,680 --> 00:29:50,520 'in which time it could mould more than 3 billion biscuits.' 527 00:29:50,520 --> 00:29:53,080 Next time you crack open the biscuit tin, 528 00:29:53,080 --> 00:29:55,000 don't forget to take a moment 529 00:29:55,000 --> 00:29:57,840 to appreciate the artistry and technology 530 00:29:57,840 --> 00:29:59,480 that's gone into that design. 531 00:30:10,000 --> 00:30:11,800 Over two hours in, 532 00:30:11,800 --> 00:30:14,360 and I'm chasing my batch of digestives 533 00:30:14,360 --> 00:30:16,080 on their way to a hot date. 534 00:30:17,520 --> 00:30:20,080 So, Gregg, this is where the biscuits enter the oven 535 00:30:20,080 --> 00:30:21,440 on their long journey. 536 00:30:21,440 --> 00:30:23,360 How long do they bake for? Six minutes. 537 00:30:24,440 --> 00:30:26,280 Through the whole strip of these ovens? 538 00:30:26,280 --> 00:30:27,920 The whole strip of these ovens. 539 00:30:27,920 --> 00:30:31,960 The oven's 80 metres long and it's divided into four zones, 540 00:30:31,960 --> 00:30:35,160 because we want certain things to happen at certain stages. 541 00:30:36,400 --> 00:30:39,560 'They bake so many biscuits here, they have 11 ovens, 542 00:30:39,560 --> 00:30:41,960 'each one using as much gas in a day 543 00:30:41,960 --> 00:30:44,560 'as an average household uses in a year.' 544 00:30:44,560 --> 00:30:46,880 Gregg, this is the first zone of the oven... 545 00:30:48,120 --> 00:30:50,520 ..and in this zone, what we want to do 546 00:30:50,520 --> 00:30:53,680 is start the biscuits rising and we want to start releasing 547 00:30:53,680 --> 00:30:56,160 some of the moisture off from the biscuit. 548 00:30:56,160 --> 00:30:59,360 So, what temperature is this one? This is 180 degrees. 549 00:30:59,360 --> 00:31:02,560 Is it? We don't want it too hot because if it's too hot, 550 00:31:02,560 --> 00:31:04,040 it will coat the biscuit, 551 00:31:04,040 --> 00:31:07,600 it'll seal in the moisture and it will just break apart. 552 00:31:07,600 --> 00:31:09,440 Can we have a look inside? We will. 553 00:31:12,120 --> 00:31:16,320 Right. They have risen probably twice their size. 554 00:31:16,320 --> 00:31:17,560 They have. 555 00:31:21,040 --> 00:31:23,400 The next zone ramps up the temperature 556 00:31:23,400 --> 00:31:26,400 to more than 250 degrees Celsius. 557 00:31:27,400 --> 00:31:31,840 The high heat forces the remaining moisture out through the 18 holes 558 00:31:31,840 --> 00:31:34,320 stamped into the top of the biscuits. 559 00:31:34,320 --> 00:31:37,760 So, up here, the biscuits have fully risen, 560 00:31:37,760 --> 00:31:40,920 we've baked all the moisture out to within spec 561 00:31:40,920 --> 00:31:42,920 and we're looking at 2.2%. 562 00:31:42,920 --> 00:31:45,280 And the biscuits are starting to colour. 563 00:31:45,280 --> 00:31:48,840 They most certainly are. Fantastic. Can I have a smell? Course you can. 564 00:31:48,840 --> 00:31:50,560 Mind you don't burn yourself! 565 00:31:51,840 --> 00:31:53,560 That's smelling like biscuits! 566 00:31:55,440 --> 00:31:59,000 The conveyor runs at just under one mile per hour... 567 00:32:00,400 --> 00:32:03,920 ..giving each digestive precisely the same time in the oven. 568 00:32:05,280 --> 00:32:10,240 And that is just a wonderful, constant floating river of biscuits. 569 00:32:10,240 --> 00:32:11,560 It is. 570 00:32:11,560 --> 00:32:14,920 # When ol' man river... # 571 00:32:14,920 --> 00:32:18,200 And now the river takes a surprising diversion. 572 00:32:19,440 --> 00:32:21,640 Because the modern production line 573 00:32:21,640 --> 00:32:23,720 has reached the walls of the old factory, 574 00:32:23,720 --> 00:32:26,160 it needs to make a 180-degree turn. 575 00:32:27,160 --> 00:32:29,720 # ..just keeps rollin' # 576 00:32:29,720 --> 00:32:34,880 It's called the Power Bend, and it's been here for almost 30 years. 577 00:32:34,880 --> 00:32:37,000 # Doo-doo-do! Keeps on rollin'... # 578 00:32:37,000 --> 00:32:38,840 Biscuits on the outside of the curve 579 00:32:38,840 --> 00:32:42,160 travel three times faster than those on the inside. 580 00:32:44,000 --> 00:32:46,040 Do you think we've made the perfect biscuit? 581 00:32:46,040 --> 00:32:48,720 I don't know, I haven't eaten one. They look good. 582 00:32:49,880 --> 00:32:52,640 'My biscuits have made it through the oven, 583 00:32:52,640 --> 00:32:54,840 'but now face a battery of tests.' 584 00:32:56,120 --> 00:32:59,840 We're going to take a biscuit off the line and measure the diameter. 585 00:33:00,840 --> 00:33:04,320 'If they're the wrong size, they won't fit in the packets 586 00:33:04,320 --> 00:33:08,040 'and the whole batch will be recycled as animal food.' 587 00:33:08,040 --> 00:33:11,200 If it fits in there, the biscuit, the diameter's too small. 588 00:33:14,120 --> 00:33:15,760 No! 589 00:33:15,760 --> 00:33:18,680 And if it fits in there, it's just right. 590 00:33:21,400 --> 00:33:24,800 That is beautifully simple. 591 00:33:24,800 --> 00:33:27,400 I like that. Like that. Right, now what? 592 00:33:27,400 --> 00:33:29,320 I want you to take nine biscuits. 593 00:33:29,320 --> 00:33:30,760 I've got one, right. 594 00:33:33,160 --> 00:33:34,640 Whoa, they're hot! 595 00:33:34,640 --> 00:33:36,160 Add them to the nine biscuits 596 00:33:36,160 --> 00:33:38,400 that we got from the other side earlier... 597 00:33:38,400 --> 00:33:41,400 Making sure the oven's cooking them evenly? That's it. 598 00:33:41,400 --> 00:33:43,560 'This is the stack height test, 599 00:33:43,560 --> 00:33:46,560 'which checks the biscuits are the correct thickness.' 600 00:33:46,560 --> 00:33:49,040 What length should the 18 biscuits be? 601 00:33:49,040 --> 00:33:52,320 We're looking at 130 millimetres. 130. 602 00:33:54,680 --> 00:33:57,920 That's just short of 130. 603 00:33:57,920 --> 00:34:00,800 We allow plus and minus one millimetre. 604 00:34:00,800 --> 00:34:03,840 Right. So, if it's 129, it's spot on. 605 00:34:03,840 --> 00:34:05,600 Yeah, you're there. You're there. 606 00:34:07,080 --> 00:34:12,480 So far, my biscuits are doing OK, measuring up at 7.2mm each. 607 00:34:13,600 --> 00:34:15,840 They're up to standard and ready to move on. 608 00:34:18,240 --> 00:34:21,160 Do you know what you need, don't you? I think. 609 00:34:21,160 --> 00:34:25,520 You need, like, a quality taster, someone with an expert palate. 610 00:34:27,120 --> 00:34:29,040 Exciting moment coming up! 611 00:34:29,040 --> 00:34:32,200 It's almost time to put the chocolate on my biscuits. 612 00:34:32,200 --> 00:34:35,120 But as Ruth's been discovering, historically, 613 00:34:35,120 --> 00:34:38,160 biscuits were more about survival than pleasure. 614 00:34:40,200 --> 00:34:43,280 A certain town in Berkshire was at the heart of it all. 615 00:34:44,720 --> 00:34:46,840 100 years ago, Reading was home 616 00:34:46,840 --> 00:34:51,280 to the world's biggest and most famous biscuit manufacturer, 617 00:34:51,280 --> 00:34:52,600 Huntley & Palmers. 618 00:34:54,960 --> 00:34:59,600 The town was dominated by the 24-acre mega-factory, 619 00:34:59,600 --> 00:35:03,440 that churned out more than 400 different types of biscuits. 620 00:35:04,640 --> 00:35:07,280 But they became notorious for just one of them. 621 00:35:08,480 --> 00:35:11,840 'I've come to Reading Museum to meet curator Brendan Carr...' 622 00:35:11,840 --> 00:35:14,000 Nice to meet you! 623 00:35:14,000 --> 00:35:16,640 '..who has some examples of the original biscuits 624 00:35:16,640 --> 00:35:19,480 'that gave the company a bad press.' 625 00:35:19,480 --> 00:35:20,840 Oh, wow! 626 00:35:20,840 --> 00:35:25,040 Now, they look like a very plain sort of biscuit! 627 00:35:26,000 --> 00:35:27,960 That's hardtack biscuit. 628 00:35:27,960 --> 00:35:30,360 What exactly is hardtack? 629 00:35:30,360 --> 00:35:34,440 Well, hardtack is just a straightforward recipe - 630 00:35:34,440 --> 00:35:38,360 it's basically flour and water, a little pinch of salt. 631 00:35:38,360 --> 00:35:41,600 These simple biscuits were easy to transport. 632 00:35:41,600 --> 00:35:45,560 So, a good source of nutrition for adventurers and the military. 633 00:35:51,360 --> 00:35:54,800 Captain Scott took Huntley & Palmers hardtack biscuits 634 00:35:54,800 --> 00:35:56,920 to the South Pole in 1910. 635 00:36:01,280 --> 00:36:04,280 Two years later, the company was the natural choice 636 00:36:04,280 --> 00:36:07,160 to manufacture and supply the biscuit rations 637 00:36:07,160 --> 00:36:10,040 issued to British soldiers in World War I. 638 00:36:13,360 --> 00:36:15,840 I can see the word "army" printed here - 639 00:36:15,840 --> 00:36:18,400 "Huntley, Palmers, Army Number Four." 640 00:36:18,400 --> 00:36:19,720 Precisely, yeah. 641 00:36:19,720 --> 00:36:22,880 There were different varieties of ration biscuit. 642 00:36:22,880 --> 00:36:25,480 When people said to you, "Your rations will be biscuits," 643 00:36:25,480 --> 00:36:27,280 in your head, you'd have been thinking of 644 00:36:27,280 --> 00:36:28,680 the biscuits you'd had at home. 645 00:36:28,680 --> 00:36:31,320 You'd be thinking of things like bourbon creams. 646 00:36:32,720 --> 00:36:34,280 You know, rich tea biscuits, 647 00:36:34,280 --> 00:36:36,520 and then you're suddenly faced with that. 648 00:36:36,520 --> 00:36:39,800 Exactly. But the British Army had to get the men fed, 649 00:36:39,800 --> 00:36:42,160 so this was like a replacement for the bread 650 00:36:42,160 --> 00:36:44,360 that the working classes would have been used to. 651 00:36:44,360 --> 00:36:46,920 And typically, what would happen is you would break it up 652 00:36:46,920 --> 00:36:49,680 with a bit of condensed milk, maybe a bit of jam if you're lucky, 653 00:36:49,680 --> 00:36:52,200 stir it up and make a bit of porridge for yourself. 654 00:36:52,200 --> 00:36:55,240 So, you wouldn't take it, dunk it in your tea and go, "Oh, yum, yum." 655 00:36:55,240 --> 00:36:57,600 No. It's quite far removed from that. 656 00:36:58,720 --> 00:37:02,120 Five million British Tommies were supplied with these biscuits. 657 00:37:02,120 --> 00:37:04,160 But they weren't exactly popular 658 00:37:04,160 --> 00:37:08,160 and the soldiers found inventive uses for their uneaten rations. 659 00:37:08,160 --> 00:37:10,560 Soldiers used to take these biscuits 660 00:37:10,560 --> 00:37:14,640 and fashion them into a little bit of, sort of, trench art. 661 00:37:14,640 --> 00:37:18,720 These have survived because they were sent home as souvenirs. 662 00:37:18,720 --> 00:37:21,600 "Have gone on hunger strike. Reason attached. 663 00:37:21,600 --> 00:37:23,920 "Mind your toes." SHE LAUGHS 664 00:37:27,680 --> 00:37:29,680 These biscuits were so disliked, 665 00:37:29,680 --> 00:37:33,000 they became a common topic for soldiers writing home. 666 00:37:34,120 --> 00:37:36,600 Hello. Nice to meet you. Lovely to meet you. 667 00:37:36,600 --> 00:37:41,280 Rhys David has some letters his father sent from the Front in 1915. 668 00:37:42,320 --> 00:37:46,120 He signed up as a very young man, on his 17th birthday, 669 00:37:46,120 --> 00:37:49,480 and from there he was shipped out to Gallipoli later that year. 670 00:37:49,480 --> 00:37:52,280 So, he was definitely one of those who was supplied 671 00:37:52,280 --> 00:37:54,720 with Huntley and Palmers biscuits. 672 00:37:54,720 --> 00:37:56,840 Yes, he writes about the biscuits 673 00:37:56,840 --> 00:38:00,160 and indicates that he wasn't very happy with them. 674 00:38:00,160 --> 00:38:02,320 He calls them "those blamed biscuits". 675 00:38:02,320 --> 00:38:05,760 In fact, he refers to the problems faced by soldiers 676 00:38:05,760 --> 00:38:07,400 who'd lost their teeth. 677 00:38:07,400 --> 00:38:09,360 I can quote to you from this. 678 00:38:09,360 --> 00:38:13,360 "We sure have had our fair share of them hateful H&Ps..." 679 00:38:13,360 --> 00:38:15,000 Huntley and Palmers. 680 00:38:15,000 --> 00:38:17,840 "Jolly glad I've got a decent lot of ivories to tackle them 681 00:38:17,840 --> 00:38:21,040 "because fellows with false 'uns don't half cop it. 682 00:38:21,040 --> 00:38:24,760 "Blooming near starved and got to break 'em up with pliers 683 00:38:24,760 --> 00:38:27,880 "to nibble at 'em." Oh, my goodness! 684 00:38:30,160 --> 00:38:33,800 But just how bad were these hardtack biscuits? 685 00:38:33,800 --> 00:38:38,280 As a surprise for Rhys, I've got some, made to the original recipe. 686 00:38:38,280 --> 00:38:42,120 Would you like to try a hardtack biscuit? Oh, thank you very much. 687 00:38:42,120 --> 00:38:44,560 Not 100 years old? Not 100 years old! 688 00:38:48,200 --> 00:38:50,200 I mean, they're all right, aren't they? 689 00:38:50,200 --> 00:38:52,160 They're not exciting, but they're OK. 690 00:38:52,160 --> 00:38:55,240 If I hadn't eaten for a few days and I was presented with one of these, 691 00:38:55,240 --> 00:38:56,760 I wouldn't be too upset. 692 00:38:56,760 --> 00:39:00,200 But I think if I was presented with these for several days in a row, 693 00:39:00,200 --> 00:39:03,200 then I would get pretty cheesed off. That was all you were getting. 694 00:39:03,200 --> 00:39:06,040 Day after day, yeah. Not horrible. They're not horrible 695 00:39:06,040 --> 00:39:08,200 but I think I'll still go for rich teas! 696 00:39:08,200 --> 00:39:09,840 SHE LAUGHS 697 00:39:16,880 --> 00:39:19,680 GREGG: At the factory, my 60,000 digestives 698 00:39:19,680 --> 00:39:21,720 have been baked to perfection. 699 00:39:21,720 --> 00:39:24,040 And now there's just one ingredient missing. 700 00:39:25,320 --> 00:39:29,400 Here, Gregg, the biscuits are on their journey from the oven. 701 00:39:29,400 --> 00:39:33,480 They're going to travel half a kilometre to the enrober. 702 00:39:33,480 --> 00:39:35,360 Enrober? Enrober. 703 00:39:35,360 --> 00:39:38,200 That's the machine that puts chocolate onto the biscuit. 704 00:39:38,200 --> 00:39:41,480 That's my sort of machine, that is, sir, my sort of machine. 705 00:39:44,080 --> 00:39:47,200 This epic 500 metre journey 706 00:39:47,200 --> 00:39:51,200 is an essential part of the manufacturing process. 707 00:39:51,200 --> 00:39:55,080 As they saunter along at a sedate 25 metres a minute, 708 00:39:55,080 --> 00:39:57,760 my biscuits are gradually cooling down, 709 00:39:57,760 --> 00:40:02,080 from 90 degrees Celsius when they leave the oven, to under 30. 710 00:40:02,080 --> 00:40:05,200 This means that when the chocolate is applied, 711 00:40:05,200 --> 00:40:08,400 they'll be the perfect temperature for it to solidify. 712 00:40:09,480 --> 00:40:12,920 We want to check that the temperature of the biscuit is correct. 713 00:40:12,920 --> 00:40:16,720 Lawrence, how do you take the temperature of a biscuit? 714 00:40:16,720 --> 00:40:18,480 And what do you do if it's got a cold? 715 00:40:19,480 --> 00:40:21,440 Give it an aspirin! 716 00:40:21,440 --> 00:40:22,720 Right, go on, show me. 717 00:40:22,720 --> 00:40:24,120 Pick a biscuit up. 718 00:40:25,320 --> 00:40:26,800 And... 719 00:40:26,800 --> 00:40:29,160 Oh, right. ..fire this thermometer at it. 720 00:40:31,160 --> 00:40:34,080 Where, there? Yeah, press the trigger. 721 00:40:34,080 --> 00:40:36,280 What have we got? 25.2. 722 00:40:36,280 --> 00:40:38,920 And what do you want? Between 24 and 28. 723 00:40:42,320 --> 00:40:44,920 My batch has nailed yet another test. 724 00:40:46,040 --> 00:40:47,880 But before we put chocolate on them... 725 00:40:47,880 --> 00:40:50,840 Oh, shut up! That's got to be, that's got to be it now?! 726 00:40:52,200 --> 00:40:55,000 It turns out the chocolate isn't ready. 727 00:40:55,000 --> 00:40:58,360 One final chemical transformation is required 728 00:40:58,360 --> 00:41:01,360 before it's good enough to grace my biscuits. 729 00:41:02,880 --> 00:41:06,080 We've got to make sure the chocolate is properly tempered. 730 00:41:06,080 --> 00:41:08,840 Can I confess something to you? I'm supposed to be a food expert, 731 00:41:08,840 --> 00:41:11,400 I don't actually know what tempering chocolate means. 732 00:41:11,400 --> 00:41:14,280 Have you ever seen a chocolatier when they take some chocolate 733 00:41:14,280 --> 00:41:16,760 and they pour it onto a slab of marble? Yeah, yeah. 734 00:41:16,760 --> 00:41:20,080 And with a palette knife, they move it around. 735 00:41:20,080 --> 00:41:22,600 And what they're doing there is what this machine does, 736 00:41:22,600 --> 00:41:24,040 but on a massive scale. 737 00:41:24,040 --> 00:41:26,560 There's the chocolate coming in... 738 00:41:26,560 --> 00:41:28,680 Is that that brown line? That's that brown line. 739 00:41:28,680 --> 00:41:30,840 Not very original, is it?! No, not really! 740 00:41:30,840 --> 00:41:33,760 And it's slowly getting the right crystals 741 00:41:33,760 --> 00:41:36,560 and getting the chocolate at the right temperature. 742 00:41:36,560 --> 00:41:41,400 The tempering tube scrapes chocolate over a series of plates, 743 00:41:41,400 --> 00:41:46,480 reducing and regulating the size of the cocoa butter crystals. 744 00:41:46,480 --> 00:41:50,200 What would the chocolate be like if it wasn't tempered? 745 00:41:50,200 --> 00:41:52,840 Well, we've got two biscuits here to show you, Gregg. 746 00:41:52,840 --> 00:41:57,320 This is one that was just coated with the untempered chocolate. 747 00:41:57,320 --> 00:42:02,040 It's dull, it melts very easy in the hand. 748 00:42:02,040 --> 00:42:05,800 It looks grainy. That does look like someone's scraped mud on it. 749 00:42:05,800 --> 00:42:07,920 And it's got no sheen. 750 00:42:07,920 --> 00:42:11,480 Chocolate is a complicated issue, isn't it? It's a science. 751 00:42:12,440 --> 00:42:14,160 It's easier eating it. I know. 752 00:42:15,280 --> 00:42:19,240 Makeover complete, the chocolate's ready for its big moment. 753 00:42:21,680 --> 00:42:24,720 I've seen the ingredients come in, I've seen you bake a biscuit, 754 00:42:24,720 --> 00:42:28,560 I've seen you test its size, I've even seen you take its temperature, 755 00:42:28,560 --> 00:42:30,280 I know how the chocolate works. 756 00:42:30,280 --> 00:42:34,080 Can I now please have some chocolate on my biscuit, Lawrence?! 757 00:42:34,080 --> 00:42:35,800 Come on, then, let's have a look. 758 00:42:35,800 --> 00:42:37,840 Are we finally going to get it? We are. 759 00:42:41,840 --> 00:42:46,680 So here, Gregg, the chocolate comes from the tempering tube, 760 00:42:46,680 --> 00:42:48,520 and we form a river of chocolate. 761 00:42:52,440 --> 00:42:55,120 This process is known as enrobing, 762 00:42:55,120 --> 00:42:57,880 a posh name for putting the chocolate on. 763 00:42:59,480 --> 00:43:01,760 I don't really get it, where's the chocolate? 764 00:43:01,760 --> 00:43:04,800 The chocolate is there, that is a river, that's a surge of chocolate. 765 00:43:04,800 --> 00:43:07,720 Oh, I see. The biscuits are coming over, 766 00:43:07,720 --> 00:43:09,800 they're sitting on little metal rafts. 767 00:43:09,800 --> 00:43:12,880 I would've expected the chocolate to be put on the top of the biscuit, 768 00:43:12,880 --> 00:43:15,640 not the bottom. We wouldn't be able to get them on quick enough, 769 00:43:15,640 --> 00:43:19,200 and we only want to coat part of the biscuit. 770 00:43:19,200 --> 00:43:21,400 I'll take a biscuit off there. 771 00:43:21,400 --> 00:43:25,040 It's only that very top part that's got the chocolate on. 772 00:43:25,040 --> 00:43:28,280 If it was poured on, it would completely cover... 773 00:43:28,280 --> 00:43:32,120 Oh, I see, it can't come down the sides? It can't come down the sides. 774 00:43:32,120 --> 00:43:34,320 Is that what's making the ripple effect? 775 00:43:34,320 --> 00:43:36,640 That's the first part of the ripple effect. 776 00:43:39,360 --> 00:43:41,480 The metal wires of the conveyor 777 00:43:41,480 --> 00:43:45,280 press a set of horizontal lines into the chocolate. 778 00:43:47,040 --> 00:43:49,320 The biscuits travel on down the rapids 779 00:43:49,320 --> 00:43:52,080 towards a set of vertical rollers 780 00:43:52,080 --> 00:43:56,840 which imprint another set of lines at right angles to the first. 781 00:43:58,680 --> 00:44:02,040 And it's this that creates the distinctive crosshatched pattern. 782 00:44:03,280 --> 00:44:06,760 I'm getting it. They're falling over it, really, aren't they? 783 00:44:06,760 --> 00:44:10,480 They are. It's a constant waterfall of chocolate biscuits. 784 00:44:14,440 --> 00:44:19,360 As they cool down to 17 degrees Celsius, the chocolate solidifies 785 00:44:19,360 --> 00:44:22,640 on what I now know is the bottom of the biscuits. 786 00:44:24,320 --> 00:44:27,840 For some of us, the perfect accompaniment to these biscuits 787 00:44:27,840 --> 00:44:29,840 is a hot drink to dunk them in. 788 00:44:29,840 --> 00:44:32,520 For others, that's a horrifying idea. 789 00:44:32,520 --> 00:44:35,280 Well, to dunk or not to dunk? 790 00:44:35,280 --> 00:44:36,720 That is the question. 791 00:44:39,360 --> 00:44:43,280 Cherry headed to Nottingham in search of the definitive answer. 792 00:44:43,280 --> 00:44:44,920 Excuse me, excuse me, excuse me. 793 00:44:44,920 --> 00:44:47,720 Can I ask you a question? Are you a dunker or not a dunker? 794 00:44:47,720 --> 00:44:49,040 Dunker or not a dunker? 795 00:44:49,040 --> 00:44:50,120 You don't drink tea? 796 00:44:50,120 --> 00:44:51,920 Not a dunker. Tea? 797 00:44:51,920 --> 00:44:54,080 Coffee, interesting. All right. 798 00:44:54,080 --> 00:44:56,640 Are you a dunker or not a dunker? 799 00:44:58,200 --> 00:44:59,720 So I would say at the moment 800 00:44:59,720 --> 00:45:03,320 Nottingham is 50-50 dunker to non-dunker. Excuse me! 801 00:45:05,760 --> 00:45:07,880 Does that upset you, the idea of it going in there 802 00:45:07,880 --> 00:45:09,080 and getting all soggy? 803 00:45:09,080 --> 00:45:11,720 Dunky-dunk, dunky-dunk... 804 00:45:11,720 --> 00:45:13,440 I love to dunk. 805 00:45:15,320 --> 00:45:17,640 But I want to find out with real science 806 00:45:17,640 --> 00:45:21,680 whether dunking really is the right way to eat a biscuit. 807 00:45:23,400 --> 00:45:27,200 I'm hoping to find the answer at the University of Nottingham, 808 00:45:27,200 --> 00:45:28,840 where Dr Ian Fisk... 809 00:45:28,840 --> 00:45:30,440 Hi, Ian, nice to meet you. 810 00:45:30,440 --> 00:45:35,000 ..is going to let me play with his state-of-the-art robot nose. 811 00:45:35,000 --> 00:45:37,360 What we're going to do today is take the biscuits, 812 00:45:37,360 --> 00:45:40,280 chew them and look at the release of aroma compounds into your nose. 813 00:45:40,280 --> 00:45:42,240 And then we're going to take the same biscuit, 814 00:45:42,240 --> 00:45:45,080 we're going to dunk it and see if the aroma release is different. 815 00:45:46,240 --> 00:45:51,480 Every time we eat food, smells, or aromas, are released into our noses. 816 00:45:51,480 --> 00:45:54,720 It's a vital part of how we taste things, 817 00:45:54,720 --> 00:45:57,040 and Ian's machine is so sensitive, 818 00:45:57,040 --> 00:45:59,720 it can detect a single aroma particle 819 00:45:59,720 --> 00:46:02,160 in 1 trillion particles of air. 820 00:46:02,160 --> 00:46:05,720 So you'll be able to tell whether the taste is better 821 00:46:05,720 --> 00:46:08,000 with or without tea? 822 00:46:08,000 --> 00:46:09,320 Let's find out. OK. 823 00:46:09,320 --> 00:46:10,720 So if you want to take a seat, 824 00:46:10,720 --> 00:46:13,320 this probe is going to go slightly up your nose. 825 00:46:13,320 --> 00:46:14,560 OK. 826 00:46:18,000 --> 00:46:19,800 So, breathe quite confidently. 827 00:46:19,800 --> 00:46:22,080 It's just a regular day at the office. 828 00:46:24,840 --> 00:46:27,720 This is not a comfortable biscuit-eating experience! 829 00:46:29,640 --> 00:46:32,840 Next, it's time to test a dunked biscuit. 830 00:46:32,840 --> 00:46:37,600 Will the robot nose detect more aroma particles or less? 831 00:46:37,600 --> 00:46:41,240 This is a big, big moment for biscuits and tea. 832 00:46:41,240 --> 00:46:43,680 All right, here we go. Dunking. 833 00:46:45,760 --> 00:46:47,320 I would say that's... SHE GASPS 834 00:46:51,480 --> 00:46:56,400 Do they taste different? To me, it definitely tastes better. 835 00:46:56,400 --> 00:47:00,160 I can taste the kind of nuttiness and the sweetness better. 836 00:47:00,160 --> 00:47:02,440 But does science agree? 837 00:47:02,440 --> 00:47:04,040 Let's have a look at the data. OK. 838 00:47:05,200 --> 00:47:08,280 So, the trace on the left is the biscuit as you ate it normally. 839 00:47:08,280 --> 00:47:11,040 The trace on the right is when you chewed it 840 00:47:11,040 --> 00:47:12,640 after it's been dunked. 841 00:47:12,640 --> 00:47:15,280 And you can see here the peak is twice as large. 842 00:47:15,280 --> 00:47:18,840 So it's not just a bit better, it's twice as good? 843 00:47:18,840 --> 00:47:23,000 Yes. So are you saying that biscuits do taste better 844 00:47:23,000 --> 00:47:26,200 when they've been dunked? That's true. 845 00:47:26,200 --> 00:47:31,400 So why does dunking a biscuit into tea make it more flavourful? 846 00:47:31,400 --> 00:47:34,080 The aroma compounds and taste compounds can diffuse out 847 00:47:34,080 --> 00:47:36,400 to the mouth and the nose much more efficiently. 848 00:47:36,400 --> 00:47:39,600 So it's not that it changes the taste of the biscuit, 849 00:47:39,600 --> 00:47:45,160 it just allows you to taste it faster and more intensely? 850 00:47:45,160 --> 00:47:47,880 Yes. Science has spoken! 851 00:47:47,880 --> 00:47:50,120 Dunkers are the winners! 852 00:47:50,120 --> 00:47:54,640 So, tea definitely improves the flavour of a biscuit 853 00:47:54,640 --> 00:47:58,560 but could other liquids be even better for dunking? 854 00:47:58,560 --> 00:48:01,360 Time to take this experiment to the streets. 855 00:48:01,360 --> 00:48:02,840 So, it's a very simple game. 856 00:48:02,840 --> 00:48:04,840 All you need to do is take a biscuit... 857 00:48:04,840 --> 00:48:08,040 Yeah. ..dunk it, and tell us which of them you prefer. 858 00:48:08,040 --> 00:48:09,640 All right, sound. 859 00:48:09,640 --> 00:48:12,160 In the green mug, we've got tea. 860 00:48:12,160 --> 00:48:14,480 In the blue, we've got coffee. 861 00:48:14,480 --> 00:48:16,760 And in the red is hot milk. 862 00:48:17,760 --> 00:48:18,800 Give it a nice dunk. 863 00:48:20,680 --> 00:48:21,880 Solid dunk, there. 864 00:48:23,000 --> 00:48:24,960 Right, have a little nibble. 865 00:48:27,640 --> 00:48:30,280 Definitely the green one. Definitely green? 866 00:48:30,280 --> 00:48:31,680 That's tea. 867 00:48:31,680 --> 00:48:33,880 You prefer coffee? Every day. 868 00:48:33,880 --> 00:48:36,000 I'd say coffee. Which is your favourite? 869 00:48:36,000 --> 00:48:37,880 Tea! Oh, yay! 870 00:48:37,880 --> 00:48:40,520 This one. Tea was your favourite. Mm-hm. 871 00:48:40,520 --> 00:48:42,960 Tea. Tea? Every time, tea. 872 00:48:42,960 --> 00:48:44,440 Every time? Every time. 873 00:48:44,440 --> 00:48:47,160 That one. Are you a coffee dunker? All the time. 874 00:48:47,160 --> 00:48:49,560 I think it's the coffee. You like the coffee? 875 00:48:49,560 --> 00:48:52,080 People just not dunking in the milk. 876 00:48:52,080 --> 00:48:53,480 They're not feeling the milk. 877 00:48:53,480 --> 00:48:55,800 Which is your favourite? 878 00:48:55,800 --> 00:48:57,880 Milk. Milk! Yeah. 879 00:48:59,600 --> 00:49:00,680 OK, it's neck and neck. 880 00:49:00,680 --> 00:49:04,200 Coffee is on four, tea is on four, milk is on one. 881 00:49:04,200 --> 00:49:05,880 So this is the decider. 882 00:49:05,880 --> 00:49:09,200 This is all down to a man called Bruce. 883 00:49:14,400 --> 00:49:16,960 Are you an experienced biscuit dunker? 884 00:49:16,960 --> 00:49:19,920 I love dunking biscuits. Yeah. 885 00:49:26,080 --> 00:49:27,640 This one. 886 00:49:27,640 --> 00:49:31,880 So, just to confirm, which is your favourite dunking drink? Tea. 887 00:49:31,880 --> 00:49:33,160 Tea! Tea. 888 00:49:33,160 --> 00:49:36,120 Absolutely in the tea? Absolutely, 100%. 889 00:49:36,120 --> 00:49:38,320 So they're like the perfect partnership? 890 00:49:38,320 --> 00:49:41,480 Absolutely, they go together like egg and bacon or... 891 00:49:41,480 --> 00:49:43,120 Jelly and ice cream. Fish and chips. 892 00:49:43,120 --> 00:49:45,400 Cats and dogs. Jelly and ice cream, cats and dogs. 893 00:49:45,400 --> 00:49:46,920 Honestly, that's the one. 894 00:49:46,920 --> 00:49:50,200 So the people of Nottingham have decided. 895 00:49:50,200 --> 00:49:52,800 Tea is the best brew for dunking, 896 00:49:52,800 --> 00:49:54,800 but does science agree? 897 00:49:54,800 --> 00:49:58,080 Ian has the results from the same test run in the lab. 898 00:49:58,080 --> 00:50:01,760 Coffee's not far off, but tea was the winner in the lab. 899 00:50:01,760 --> 00:50:05,320 So, in conclusion, in the lab and on the streets, 900 00:50:05,320 --> 00:50:07,560 tea is the dunking champion. 901 00:50:07,560 --> 00:50:09,640 Absolutely. That was a slam dunk. 902 00:50:17,360 --> 00:50:19,440 In London, two hours and 35 minutes 903 00:50:19,440 --> 00:50:22,000 after the flour arrived at the factory, 904 00:50:22,000 --> 00:50:25,240 my biscuits have made it to the packing hall. 905 00:50:25,240 --> 00:50:27,840 Fraser Jones has worked here for 20 years 906 00:50:27,840 --> 00:50:31,440 and he's going to fill me in on the final steps of their journey. 907 00:50:32,480 --> 00:50:34,080 Fraser. Gregg, you all right? 908 00:50:34,080 --> 00:50:37,200 I've watched these biscuits being made every single step of the way. 909 00:50:37,200 --> 00:50:40,200 Yeah. Once they come out into here, what happens now? 910 00:50:40,200 --> 00:50:43,320 Now we need to get them orientated ready for packing. 911 00:50:43,320 --> 00:50:47,240 We've got to do that as quickly and as gently as we can. 912 00:50:47,240 --> 00:50:48,840 We don't want to damage the product. 913 00:50:48,840 --> 00:50:51,160 So what's the first stage? What's this bit? 914 00:50:51,160 --> 00:50:52,960 We've got 18 lanes of biscuits 915 00:50:52,960 --> 00:50:55,200 so the biscuits come onto this air bed 916 00:50:55,200 --> 00:50:59,080 and these diverter arms split all the product into groups of three. 917 00:50:59,080 --> 00:51:00,800 Air bed? 918 00:51:00,800 --> 00:51:03,560 This table here has a big fan underneath 919 00:51:03,560 --> 00:51:06,440 that lifts the biscuits off of the surface 920 00:51:06,440 --> 00:51:08,520 so it cuts out all the friction, 921 00:51:08,520 --> 00:51:11,400 and we have a very gentle and smooth travel. 922 00:51:11,400 --> 00:51:14,320 It reminds me of an air hockey table. 923 00:51:14,320 --> 00:51:16,240 That's exactly the same philosophy. 924 00:51:16,240 --> 00:51:19,040 How many people munching a chocolate biscuit imagine 925 00:51:19,040 --> 00:51:21,480 that they may have floated into the wrapper? 926 00:51:21,480 --> 00:51:24,120 It's like a magic carpet ride for biscuits! 927 00:51:24,120 --> 00:51:25,680 What's the next stage? 928 00:51:25,680 --> 00:51:28,920 We split them into a further three channels, so these shakers... 929 00:51:29,960 --> 00:51:33,480 ..divide the biscuits so we've now got six groups. 930 00:51:33,480 --> 00:51:35,560 So you can see, they're all interlocking 931 00:51:35,560 --> 00:51:38,520 and they're being presented perfectly to these slopes. 932 00:51:41,800 --> 00:51:44,240 Shaking dividers jostle the biscuits 933 00:51:44,240 --> 00:51:46,680 so they can make the perfect landing. 934 00:51:48,160 --> 00:51:50,120 One on top of the other. 935 00:51:52,120 --> 00:51:55,440 So they'll fall down this slope one by one and not two at the same time? 936 00:51:55,440 --> 00:51:57,120 Correct. Oh, my word! 937 00:51:57,120 --> 00:51:58,880 Who designs this stuff? 938 00:52:13,240 --> 00:52:17,400 I've been following these biscuits all the way along the line. 939 00:52:17,400 --> 00:52:19,560 Can I finally get to eat one? 940 00:52:19,560 --> 00:52:22,200 As it's you, Gregg, you can have a taste. Why not? 941 00:52:23,920 --> 00:52:25,960 I've waited a long time for this. 942 00:52:25,960 --> 00:52:27,000 Worth waiting for. 943 00:52:30,320 --> 00:52:32,760 At last! Well worth waiting for. 944 00:52:39,840 --> 00:52:43,440 As the digestives arrive at the end of this ingenious machine, 945 00:52:43,440 --> 00:52:48,040 they're divided into groups of 18 biscuits, ready for each packet. 946 00:52:50,320 --> 00:52:52,960 Then they're wrapped in a polypropylene sheet. 947 00:52:52,960 --> 00:52:56,520 Heated rollers seal the bottom and each end. 948 00:52:56,520 --> 00:52:59,680 Where's it being cut? Well, if you just look here, Gregg... 949 00:52:59,680 --> 00:53:04,520 you've got two shafts with heated knives, if you want, 950 00:53:04,520 --> 00:53:06,880 and that creates the seal 951 00:53:06,880 --> 00:53:10,400 and they're perfectly timed to cut the packet 952 00:53:10,400 --> 00:53:13,720 exactly in the middle of each stack of biscuits. 953 00:53:15,280 --> 00:53:16,560 And if that goes wrong, 954 00:53:16,560 --> 00:53:18,880 it starts cutting the packets of biscuits in half? 955 00:53:18,880 --> 00:53:21,200 Oh, yeah. Makes a right mess. 956 00:53:22,920 --> 00:53:25,520 And it does happen, right? Oh, yeah, occasionally. 957 00:53:28,600 --> 00:53:31,600 My batch of biscuits is now safely housed 958 00:53:31,600 --> 00:53:34,520 in more than 3,000 individual packets. 959 00:53:34,520 --> 00:53:39,240 Suckers lift and pack them into 277 boxes 960 00:53:39,240 --> 00:53:41,880 and then it's a quick seven-minute trip 961 00:53:41,880 --> 00:53:44,720 down a biscuit superhighway to dispatch. 962 00:53:54,480 --> 00:53:58,360 It's a land of robots, overseen by one man - 963 00:53:58,360 --> 00:54:02,080 Marcus Pymer, supply chain manager. 964 00:54:02,080 --> 00:54:04,200 Whoa! 965 00:54:04,200 --> 00:54:06,720 Now, this is a crazy room. 966 00:54:06,720 --> 00:54:09,840 Eight tangerine-coloured robots, right? 967 00:54:09,840 --> 00:54:13,600 Yeah. And they're all packing a different brand of biscuits? 968 00:54:13,600 --> 00:54:15,360 Yes, they are. 969 00:54:18,960 --> 00:54:22,800 As my digestives arrive, they're all mixed up with other boxes. 970 00:54:24,120 --> 00:54:29,600 This 115-year-old site is too small to send eight production lines 971 00:54:29,600 --> 00:54:32,120 straight into dispatch on their own conveyors. 972 00:54:33,840 --> 00:54:36,520 So they're merged onto just two lines 973 00:54:36,520 --> 00:54:39,960 and my boxes have to join the queue. 974 00:54:39,960 --> 00:54:45,120 How does it work? It's a bit like an airport baggage handling system. 975 00:54:45,120 --> 00:54:47,440 On the case, you have a QR code. 976 00:54:48,600 --> 00:54:52,480 I've got a camera that takes a picture of the code. 977 00:54:52,480 --> 00:54:54,240 Once it's taken the picture, 978 00:54:54,240 --> 00:54:58,480 the system knows which robot to put the case onto. 979 00:54:59,800 --> 00:55:02,520 My chocolate digestives are identified, 980 00:55:02,520 --> 00:55:05,680 separated out from the other types of biscuits, 981 00:55:05,680 --> 00:55:09,320 and directed towards the correct packing robot. 982 00:55:09,320 --> 00:55:12,480 Each one is named after a London station. 983 00:55:12,480 --> 00:55:15,400 Which station has got my chocolate biscuits? 984 00:55:15,400 --> 00:55:19,280 Your chocolate biscuits are being produced on St Pancras. 985 00:55:19,280 --> 00:55:21,720 No, I want that changed. I'm not happy with that. 986 00:55:22,760 --> 00:55:25,440 As a south London boy, that's disappointing! 987 00:55:30,280 --> 00:55:33,560 Each robot can pack 800 boxes an hour, 988 00:55:33,560 --> 00:55:36,000 stacking them in pre-programmed patterns 989 00:55:36,000 --> 00:55:37,840 and loading them onto pallets. 990 00:55:39,960 --> 00:55:44,960 From there, there's a signal sent to the two travel carts in the middle, 991 00:55:44,960 --> 00:55:50,160 so one will come down, pick up the full pallet and take it away. 992 00:55:50,160 --> 00:55:52,280 While it's taking the full pallet away, 993 00:55:52,280 --> 00:55:55,240 another cart will bring an empty and put it in its place. 994 00:55:58,600 --> 00:56:02,000 These are the pallets I've seen put together by the robots, yeah? 995 00:56:02,000 --> 00:56:05,720 That's correct, Gregg, yes. Right, and what stage is this, then? 996 00:56:05,720 --> 00:56:08,800 So this is just getting ready to load them onto the trailers 997 00:56:08,800 --> 00:56:12,000 that are behind you, Gregg. But where do you store them all? 998 00:56:12,000 --> 00:56:16,840 I don't. So basically, they come off that automated palletisation system, 999 00:56:16,840 --> 00:56:19,640 come on to here and then my forklift driver will load them 1000 00:56:19,640 --> 00:56:21,920 onto the trailer behind you, and they go off. 1001 00:56:21,920 --> 00:56:24,880 So as soon as they're made... Yeah. ..they're boxed... 1002 00:56:24,880 --> 00:56:27,000 Yeah. ..palleted and out? 1003 00:56:27,000 --> 00:56:28,200 Yes. 1004 00:56:28,200 --> 00:56:30,840 No warehouse storage at all? No. 1005 00:56:30,840 --> 00:56:33,880 They only have enough space here 1006 00:56:33,880 --> 00:56:37,760 to store two hours' worth of freshly baked biscuits. 1007 00:56:42,280 --> 00:56:44,000 How many lorries go out of here? 1008 00:56:44,000 --> 00:56:47,400 We average about 34 trailers every 24 hours. 1009 00:56:47,400 --> 00:56:49,240 Nearly one and a half every hour? 1010 00:56:49,240 --> 00:56:52,400 Yes. And what do you have nightmares about? 1011 00:56:52,400 --> 00:56:55,480 What worries you? Um...conveyors going down. 1012 00:56:55,480 --> 00:56:57,560 Trailers not turning up. 1013 00:56:57,560 --> 00:56:59,120 Weather. Why the weather? 1014 00:56:59,120 --> 00:57:02,600 Because we can't load your chocolate digestives if it's too hot, 1015 00:57:02,600 --> 00:57:04,200 because it melts the chocolate. 1016 00:57:04,200 --> 00:57:07,960 The one good thing about this, if you have any hold-up at all, 1017 00:57:07,960 --> 00:57:10,600 you can have a cup of tea and a biscuit. Correct. 1018 00:57:10,600 --> 00:57:14,800 From here, the chocolate digestives head to a distribution centre 1019 00:57:14,800 --> 00:57:16,800 and off to the shops. 1020 00:57:16,800 --> 00:57:19,400 84% are consumed in the UK. 1021 00:57:19,400 --> 00:57:22,720 People in Sheffield and Glasgow are the biggest biscuit lovers, 1022 00:57:22,720 --> 00:57:25,520 but Lancashire munches more chocolate digestives 1023 00:57:25,520 --> 00:57:27,280 than anywhere else. 1024 00:57:27,280 --> 00:57:32,160 I'm a Londoner and I had no idea in London was a factory 1025 00:57:32,160 --> 00:57:37,440 churning out 13 million chocolate digestives every 24 hours. 1026 00:57:37,440 --> 00:57:39,720 I certainly didn't expect to see them 1027 00:57:39,720 --> 00:57:41,960 floating along on their own air bed. 1028 00:57:41,960 --> 00:57:44,720 But what I learned that really surprised me 1029 00:57:44,720 --> 00:57:48,520 was they put the chocolate on the bottom of the biscuit. 1030 00:57:48,520 --> 00:57:49,720 Who knew? 1031 00:57:49,720 --> 00:57:51,920 Raj, take it away, mate. 1032 00:58:04,680 --> 00:58:09,560 It's taken a touch over four hours, but my biscuits are out and about... 1033 00:58:10,840 --> 00:58:14,240 ..heading towards the shelves of a shop near you.