0:00:02 > 0:00:04We are a nation of snackers.
0:00:04 > 0:00:09Over the next 24 hours, we will get through half a billion crisps.
0:00:09 > 0:00:13That takes over 17 million potatoes a day
0:00:13 > 0:00:17grown and harvested on UK farms like this one in Hampshire.
0:00:20 > 0:00:24Tonight, we'll reveal just what it takes to produce crisps
0:00:24 > 0:00:26on such a mind-boggling scale.
0:00:26 > 0:00:32As we give you a rare look inside the largest crisp factory on earth.
0:00:35 > 0:00:37'I'm Gregg Wallace.'
0:00:37 > 0:00:38Bring her in.
0:00:38 > 0:00:41'And tonight I'll join the race to keep up with demand
0:00:41 > 0:00:42'for our favourite snack.'
0:00:44 > 0:00:45That's a packet of crisps?
0:00:45 > 0:00:48HE LAUGHS How does it do it that fast?
0:00:48 > 0:00:52'I'll meet the super tasters testing every new flavour.'
0:00:52 > 0:00:54- There is a sourness, isn't there? - What, like curd?
0:00:54 > 0:00:56It's a bit like baby sick.
0:00:56 > 0:01:00'And reveal the tricks this factory uses to keep your crisps fresh.'
0:01:00 > 0:01:04In every bag of crisps is a bag of nitrogen?
0:01:04 > 0:01:05'I'm Cherry Healey.'
0:01:05 > 0:01:07That smells really good.
0:01:07 > 0:01:11'And I'll discover the secrets of the perfect crisp potato.'
0:01:11 > 0:01:13Why are they so dark?
0:01:13 > 0:01:16Because they have a lot of sugar which has caramelised.
0:01:16 > 0:01:19'And the surprising ways your brain can be tricked
0:01:19 > 0:01:22'into tasting something that's not there.'
0:01:22 > 0:01:25- It's really tricky.- I thought I knew a lot about crisps.
0:01:25 > 0:01:30'Historian Ruth Goodman uncovers who really invented the crisp.'
0:01:30 > 0:01:34We are going to have to rethink crisp history.
0:01:34 > 0:01:37I love this. I want to ride down this in a kayak.
0:01:37 > 0:01:41'We spend more on crisps than anywhere else in Europe.'
0:01:41 > 0:01:45Every day over five million packets of crisps
0:01:45 > 0:01:47fly out of this one factory.
0:01:47 > 0:01:50It's an incredible feat of logistics and engineering.
0:01:50 > 0:01:54You'll never look at a humble packet of crisps in the same way again.
0:01:54 > 0:01:58Welcome to Inside The Factory.
0:02:17 > 0:02:19This is Walker's in Leicester,
0:02:19 > 0:02:22the biggest crisp factory in the world.
0:02:30 > 0:02:33The crisp has gone through something of a gourmet revolution
0:02:33 > 0:02:36over the last few years and you can now get all sorts of posh flavours
0:02:36 > 0:02:38from langoustine and lemon
0:02:38 > 0:02:41to white stilton and cranberry relish.
0:02:41 > 0:02:45But tonight, we are following the nation's biggest seller -
0:02:45 > 0:02:47cheese and onion.
0:02:47 > 0:02:49Which is a bit of a disappointment to me
0:02:49 > 0:02:52because I'm very much a prawn cocktail man.
0:02:53 > 0:02:56More than 40% of the crisps eaten in Britain
0:02:56 > 0:02:59come out of this one factory.
0:02:59 > 0:03:02It runs around the clock, seven days a week.
0:03:02 > 0:03:05But whether they are making ready salted
0:03:05 > 0:03:07or something a bit more exotic,
0:03:07 > 0:03:11the 24-hour production process begins on the farm
0:03:11 > 0:03:13with the right spud.
0:03:13 > 0:03:19Almost all crisp produced in the UK are made with British potatoes.
0:03:19 > 0:03:24The most popular varieties are Markies, Lady Rosetta and Hermes.
0:03:25 > 0:03:27The process of making our crisps starts here
0:03:27 > 0:03:30on the Hampshire potato farm of Gavin Janaway
0:03:30 > 0:03:35whose family have been growing crisp spuds since the 1970s.
0:03:36 > 0:03:39These will be going to the crisp factory later on today.
0:03:39 > 0:03:41Have they just been dug or have they been in store?
0:03:41 > 0:03:43No, these have been in store now for about six months.
0:03:43 > 0:03:46We keep them at the right temperature, the right humidity
0:03:46 > 0:03:47with fresh air going in there
0:03:47 > 0:03:49because a potato is a living, breathing thing.
0:03:49 > 0:03:52You know, we've got to try and keep it happy and keep it warm
0:03:52 > 0:03:53so it produces a good crisp.
0:03:53 > 0:03:55How do you know when they're growing in the ground
0:03:55 > 0:03:58that they are going to be perfect for the crisp? You can't tell.
0:03:58 > 0:04:00Well, to try and help us tell, Gregg,
0:04:00 > 0:04:02we've got our own little frying facility on site here,
0:04:02 > 0:04:04our little potato lab.
0:04:04 > 0:04:07And we take samples from the field throughout the growing season
0:04:07 > 0:04:09and throughout the storage season and we take them to there,
0:04:09 > 0:04:11we test them and we actually fry them ourselves.
0:04:11 > 0:04:14So, I do my own little MasterChef, a little cooking myself,
0:04:14 > 0:04:17with a little bit of salt and pepper - just the right seasoning.
0:04:17 > 0:04:19We test them to make sure they're right for the factory.
0:04:19 > 0:04:22If they're not ready when we fry them at the field, we just give them
0:04:22 > 0:04:24another couple of weeks and a bit of sunshine and everything
0:04:24 > 0:04:29- will help them mature.- At any one time, Gavin could be storing
0:04:29 > 0:04:33as many as 160 million potatoes on his farm.
0:04:33 > 0:04:36When they get the order through from the factory,
0:04:36 > 0:04:38the potatoes are fed into one end of a production line
0:04:38 > 0:04:43which can sort, wash and load 27 tonnes of spuds
0:04:43 > 0:04:46onto a truck in less than 45 minutes.
0:04:48 > 0:04:52Here we go. A nice big crate of British spuds.
0:04:53 > 0:04:58How long before that lovely spud becomes a cheese and onion crisp?
0:04:58 > 0:05:01That could be a cheese and onion crisp within six hours.
0:05:02 > 0:05:05This is where our crisp production line starts.
0:05:08 > 0:05:10So, we're now just looking for anything that's green
0:05:10 > 0:05:13or has got damage on it or maybe a little shoot on it,
0:05:13 > 0:05:15anything that may affect the quality.
0:05:15 > 0:05:17- So, take the sprouts out. - Something like this.
0:05:17 > 0:05:20This is damage that's been done through harvesting
0:05:20 > 0:05:22so that's mechanical damage. That comes out.
0:05:22 > 0:05:24- There's another one. - That comes out.
0:05:26 > 0:05:30Yeah, you won't beat him, he's too quick. He's the fastest one here.
0:05:30 > 0:05:31Nobody beats Gregosh.
0:05:31 > 0:05:34It doesn't surprise me the best one here is called Greg.
0:05:35 > 0:05:38How often are you set up like this?
0:05:38 > 0:05:39This is set up all year round
0:05:39 > 0:05:42so we can load any day of the week all year round.
0:05:42 > 0:05:45Ay, a green one! I got that before Gregosh.
0:05:45 > 0:05:48How many potatoes on a lorry load?
0:05:48 > 0:05:50There's 27 tonnes
0:05:50 > 0:05:54so I think that works out roughly 200,000 packets of crisps
0:05:54 > 0:05:56in one lorry load.
0:05:56 > 0:05:59- How many lorries go out? - A busy day would be ten lorries.
0:05:59 > 0:06:02So that means on a busy day you send out two million bags of crisps.
0:06:02 > 0:06:03Yeah.
0:06:08 > 0:06:10This is a Hermes potato.
0:06:10 > 0:06:14Over 300 million of these are grown in Britain every year
0:06:14 > 0:06:16but you won't ever have seen one in the supermarket
0:06:16 > 0:06:20because, as Cherry is finding out, to make crisps,
0:06:20 > 0:06:22you need a very specific potato.
0:06:32 > 0:06:35I have to admit, I find potato shopping a little bit daunting.
0:06:35 > 0:06:38There are so many different varieties
0:06:38 > 0:06:41and I never know which one to buy.
0:06:41 > 0:06:47In fact, there are more than 230 varieties of potato grown in the UK.
0:06:48 > 0:06:51About half of those will end up in your produce aisle
0:06:51 > 0:06:54but the other varieties are used
0:06:54 > 0:06:57to make everything from frozen waffles to vodka.
0:06:57 > 0:07:01But which variety makes the perfect crisps?
0:07:01 > 0:07:04To find out, I'm heading to potato HQ,
0:07:04 > 0:07:07the National Agronomy Centre in Cambridge,
0:07:07 > 0:07:10where James Fowler is a spud expert.
0:07:10 > 0:07:13- Ready to go in? - Ready to go.- Here we go.
0:07:13 > 0:07:15We're going to have a crisp fry up
0:07:15 > 0:07:19but with three very different varieties of potato.
0:07:19 > 0:07:22I've brought some Maris Peers,
0:07:22 > 0:07:25a waxy new potato great for salads,
0:07:25 > 0:07:30some King Edwards, a more floury potato perfect for mashing
0:07:30 > 0:07:32and James has got this one.
0:07:32 > 0:07:34You won't have seen this one, Cherry,
0:07:34 > 0:07:37it's a specialist crisping variety we're investigating at the moment.
0:07:37 > 0:07:41- We think it's going to make good crisps.- It's brand-new?
0:07:41 > 0:07:43- Yeah, it's... - It's a revolutionary potato.
0:07:43 > 0:07:46'The first obvious difference is the shape.'
0:07:46 > 0:07:48Crisping varieties should be predominantly round.
0:07:48 > 0:07:51Not long like this Maris Peer.
0:07:51 > 0:07:54If they're too small, the crisps are too small
0:07:54 > 0:07:56and the bags look half empty
0:07:56 > 0:07:59and also there's a lot more peeling waste when you process them.
0:07:59 > 0:08:02But the differences are more than skin deep.
0:08:02 > 0:08:04When it comes to making crisps,
0:08:04 > 0:08:07there are three key parts of a potato -
0:08:07 > 0:08:11water, which makes up about 80% of the average spud,
0:08:11 > 0:08:14starch and tiny amounts of natural sugar.
0:08:14 > 0:08:18Using a hydrometer, you can tell how much water there is.
0:08:18 > 0:08:20My two potatoes are about 80% water
0:08:20 > 0:08:25but a good crisp potato has only 75%.
0:08:25 > 0:08:26The less water, the better
0:08:26 > 0:08:30because you need to get rid of almost all of it to make a crisp.
0:08:30 > 0:08:32Now the fun bit.
0:08:32 > 0:08:36'Now we fry all three potatoes in exactly the same way.'
0:08:37 > 0:08:39The water is boiling off.
0:08:39 > 0:08:42- And that's what's causing all this steam?- That's right.
0:08:42 > 0:08:45If there's more water in a potato,
0:08:45 > 0:08:48when it goes to the factory, you get more steam...
0:08:48 > 0:08:49And fewer crisps.
0:08:49 > 0:08:52And that's not what you want if you're making crisps.
0:08:52 > 0:08:55'But when it comes to making light, golden crisps
0:08:55 > 0:09:00'on an industrial scale, the biggest enemy is sugar.'
0:09:00 > 0:09:02Wow.
0:09:02 > 0:09:05Why are they so dark?
0:09:05 > 0:09:07Because they have a lot of sugar which has caramelised
0:09:07 > 0:09:08and produced the dark colour.
0:09:08 > 0:09:13'The King Edwards have less sugar and so are noticeably lighter.
0:09:13 > 0:09:16'Finally, we fry the specialist crisp potatoes
0:09:16 > 0:09:19'at the same temperature as the other two.
0:09:19 > 0:09:24'Not only do they cook much faster, they look completely different.'
0:09:24 > 0:09:28- They look better.- Wow. So those are much more familiar.
0:09:28 > 0:09:29Less sugar.
0:09:29 > 0:09:32- Less sugar.- Less sugar, there's no colour development.
0:09:32 > 0:09:34The subtle differences of potatoes
0:09:34 > 0:09:37might not matter much if you're just having a fry up at home
0:09:37 > 0:09:39but for the nation's biggest crisp makers
0:09:39 > 0:09:42making tens of millions of them every day,
0:09:42 > 0:09:45the science of spuds is everything.
0:09:45 > 0:09:47Mmm.
0:09:51 > 0:09:53The potatoes I helped load at the farm
0:09:53 > 0:09:56have made the three-hour journey from Hampshire
0:09:56 > 0:09:58to the factory in Leicester.
0:10:00 > 0:10:04Where factory manager Simon Devaney is ready and waiting.
0:10:04 > 0:10:06Come on, bring her in.
0:10:09 > 0:10:12How many potatoes have we got on there, do you know?
0:10:12 > 0:10:14There's about 200,000 potatoes on average.
0:10:14 > 0:10:17And how many trucks like that come in every day?
0:10:17 > 0:10:20We get about 25 every single day, 24 hours a day.
0:10:20 > 0:10:23So, that's about five million potatoes every day.
0:10:23 > 0:10:29How many potatoes in one standard packet of crisps?
0:10:29 > 0:10:32Well, we're using about five million potatoes every day
0:10:32 > 0:10:34and we're making about five million packets every day.
0:10:34 > 0:10:37- That's a packet of crisps? - That's a packet of crisps.
0:10:37 > 0:10:38That's a packet of crisps?
0:10:38 > 0:10:41Five million potatoes in, five million bags of crisps out.
0:10:41 > 0:10:42Dead right.
0:10:42 > 0:10:46I love this. I absolutely love this.
0:10:46 > 0:10:50'My first job is to climb aboard and collect a sample.'
0:10:50 > 0:10:53Righto, they make lovely chips, tell your mum.
0:10:53 > 0:10:56Guaranteed to bake or fry, make a pudding or a pie.
0:10:56 > 0:10:59Call me a saint, call me sinner, call it a tenner.
0:11:00 > 0:11:03Then we conduct the same test Cherry did in the lab
0:11:03 > 0:11:07to measure the exact water content in this truck load of spuds.
0:11:07 > 0:11:10Understanding the solids content of the potato
0:11:10 > 0:11:11is absolutely critical.
0:11:11 > 0:11:14The amount of water in that potato is going to vary through the year
0:11:14 > 0:11:15and if we know that,
0:11:15 > 0:11:19it ensures we can make the right quality of crisp consistently.
0:11:19 > 0:11:22Every batch of potatoes is going to be slightly different, right?
0:11:22 > 0:11:23That's right.
0:11:23 > 0:11:25And you will adjust the heat,
0:11:25 > 0:11:28adjust the cooking temperature of the potato
0:11:28 > 0:11:30depending on what the potatoes are on every lorry load.
0:11:30 > 0:11:33- Every single load.- Now what?
0:11:33 > 0:11:36This product is good. Let's start making some crisps.
0:11:37 > 0:11:40Potatoes are much more delicate than they might seem
0:11:40 > 0:11:42and can easily bruise.
0:11:42 > 0:11:46So, the best way to get 200,000 spuds off a lorry?
0:11:46 > 0:11:48Float them off.
0:11:48 > 0:11:50Fire her up! Let's go!
0:11:53 > 0:11:58Ay! That's a fair amount of water there, old son.
0:11:58 > 0:12:02They basically flood the compartment of the truck
0:12:02 > 0:12:05and the potatoes just come out with the water.
0:12:05 > 0:12:06Exactly right.
0:12:13 > 0:12:15But that now is a very wet potato.
0:12:15 > 0:12:18I mean, that is going to start to deteriorate.
0:12:18 > 0:12:19You can't keep potatoes in water.
0:12:19 > 0:12:22No. So, time is of the essence
0:12:22 > 0:12:25but in 35 minutes, it's going to be in a packet of crisps.
0:12:26 > 0:12:27What?
0:12:27 > 0:12:2935 minutes.
0:12:29 > 0:12:32Just over half an hour and you turn that into crisps.
0:12:32 > 0:12:33That can't happen.
0:12:33 > 0:12:36I can't make chips in that time.
0:12:39 > 0:12:43This potato, this one here, just to make sure, right,
0:12:43 > 0:12:46is going to be a packet of cheese and onion crisps in 35 minutes.
0:12:46 > 0:12:4835 minutes.
0:12:48 > 0:12:53OK. Your time starts right now.
0:12:54 > 0:12:58- I'll see that in just over half an hour's time...- Yeah.
0:12:58 > 0:13:00..in a little blue bag.
0:13:02 > 0:13:06When you're dealing with five million potatoes a day,
0:13:06 > 0:13:09you need an efficient way of peeling them.
0:13:10 > 0:13:13And here, in the world's biggest crisp factory,
0:13:13 > 0:13:18they have to peel more than 2,000 every minute.
0:13:18 > 0:13:21To do that, you need some hard-core potato peelers.
0:13:24 > 0:13:27We're using a thing called abrasion peeling here.
0:13:27 > 0:13:30Something that your grandma might actually have had in her kitchen.
0:13:30 > 0:13:33We're spinning the potatoes round against a rough surface,
0:13:33 > 0:13:37a little bit like sandpaper, and just removing a small amount of
0:13:37 > 0:13:42that peel to leave a clean potato ready for the next process.
0:13:42 > 0:13:44That's quite an aggressive rumble.
0:13:44 > 0:13:47- You cannot only see it, you can feel it under your feet.- Yeah.
0:13:49 > 0:13:51You've got potatoes coming in all year.
0:13:51 > 0:13:53- That's right.- All year.
0:13:53 > 0:13:56- The thickness of the skin is going to change.- Yeah.
0:13:56 > 0:13:58You're a greengrocer, so you know this stuff.
0:13:58 > 0:14:01So, a new potato that you might have with your salad in the summer
0:14:01 > 0:14:03has got a very light skin,
0:14:03 > 0:14:05that's the same for the crisps as well.
0:14:05 > 0:14:07So we need to handle that much more gently
0:14:07 > 0:14:11by giving it a very light peel, five or ten seconds,
0:14:11 > 0:14:14versus that one in the springtime, which is more like a jacket potato,
0:14:14 > 0:14:16that's going to take a little bit longer.
0:14:16 > 0:14:19How do you know you've peeled them all properly?
0:14:19 > 0:14:21Because even if I do half a bag of potatoes,
0:14:21 > 0:14:23sometimes I might miss a bit.
0:14:23 > 0:14:26We've got a whole series of digital cameras here
0:14:26 > 0:14:29and they are looking at every single potato.
0:14:29 > 0:14:31- It photographs every single one? - Every single one.
0:14:31 > 0:14:35To the side here, you can see what looks a little bit like
0:14:35 > 0:14:37a piano keyboard, a series of fingers.
0:14:37 > 0:14:39If we get a bad potato coming through,
0:14:39 > 0:14:41you'll hear a gust of air
0:14:41 > 0:14:45and that will kick that potato out, that will be rejected.
0:14:45 > 0:14:46That's a bit nuts, mate.
0:14:48 > 0:14:50HE LAUGHS How does it do it that fast?
0:14:56 > 0:15:01My potato is about to be sliced and fried and turned into a crisp.
0:15:01 > 0:15:05A process that will be repeated five million times today.
0:15:05 > 0:15:08But who first did it? Who invented the crisp?
0:15:08 > 0:15:11That's a question Ruth Goodman is trying to answer.
0:15:11 > 0:15:13And it's not as simple as it sounds.
0:15:17 > 0:15:19If you speak to Americans,
0:15:19 > 0:15:24they will tell you that they invented the crisp in 1853.
0:15:24 > 0:15:27And that it's down to a man called George Crum,
0:15:27 > 0:15:30a chef who was working in a country club in New York State.
0:15:30 > 0:15:33And the story goes that the chef Crum
0:15:33 > 0:15:35had a particularly difficult customer,
0:15:35 > 0:15:39a wealthy industrialist, who kept sending his chips back
0:15:39 > 0:15:42saying they weren't thin enough.
0:15:43 > 0:15:47George got so fed up in the end that he decided to make the chips
0:15:47 > 0:15:52so thin that they would be inedible and then he covered them in salt.
0:15:52 > 0:15:56Much to his surprise, the customer loved them.
0:15:56 > 0:15:58So much so, that he put them on the menu.
0:15:58 > 0:16:02But for me, there's something fishy about this story.
0:16:02 > 0:16:06We've been cooking potatoes for 200 years before
0:16:06 > 0:16:08the Americans claimed to have invented the crisp.
0:16:08 > 0:16:13Surely we'd come up with a similar recipe before then.
0:16:18 > 0:16:20To get to the bottom of this mystery
0:16:20 > 0:16:23and find out once and for all who invented the crisp,
0:16:23 > 0:16:27I'm meeting food historian Regina Sexton to plot the history
0:16:27 > 0:16:29of the humble crisp.
0:16:29 > 0:16:33The potato is in England by the 1580s, the 1590s,
0:16:33 > 0:16:36is looked upon as an exotic thing.
0:16:36 > 0:16:40So, something desirable, a plant for people to have in their gardens.
0:16:40 > 0:16:45Gradually, potatoes moved from being just a specimen plant
0:16:45 > 0:16:47to become something that we started to eat
0:16:47 > 0:16:51and by the 18th century, they had become the staple of the Irish poor.
0:16:51 > 0:16:58Soon they were eating an astonishing 12 to 14 pounds per person per day.
0:16:58 > 0:17:00I can hardly even lift that.
0:17:00 > 0:17:04- That is a huge amount of potato. - It is.
0:17:04 > 0:17:08- But that's it. That's the only thing you eat all day?- Yeah.
0:17:08 > 0:17:11As Britain's population exploded in the 19th century,
0:17:11 > 0:17:14the potato became a culinary mainstay.
0:17:14 > 0:17:16One of the most popular Victorian cookery books was
0:17:16 > 0:17:19William Kitchener's The Cook's Oracle,
0:17:19 > 0:17:21first published in 1817.
0:17:21 > 0:17:24- This book, in fact, was a bestseller in its day.- Oh, really?
0:17:24 > 0:17:27I love this, "The vegetable kingdom affords no food more wholesome,
0:17:27 > 0:17:29"more easily procured, easily prepared
0:17:29 > 0:17:31"or less expensive than the potato."
0:17:31 > 0:17:34'It's packed with potato recipes
0:17:34 > 0:17:38'including one that's quite familiar.'
0:17:38 > 0:17:41"Potatoes fried in slices or shavings."
0:17:41 > 0:17:44Now, that's a really interesting recipe if you read through it.
0:17:44 > 0:17:46"Fry them in lard or dripping
0:17:46 > 0:17:49- "and keep moving them until they are crisp."- Crisp.
0:17:49 > 0:17:52- What date did you say this was? - 1817.
0:17:52 > 0:17:531817.
0:17:53 > 0:17:56So, that's quite a bit before 1853
0:17:56 > 0:18:00- when the Americans say they invented the crisp, isn't it?- Yes, it is.
0:18:00 > 0:18:03So, if we cook this and it really turns out to be a crisp,
0:18:03 > 0:18:07then we are going to have to rethink crisp history.
0:18:07 > 0:18:09I think we might have to.
0:18:10 > 0:18:13The only way to find out if this really is
0:18:13 > 0:18:15the very first recipe for crisps,
0:18:15 > 0:18:1836 years before it was claimed that George Crum invented them
0:18:18 > 0:18:23in America, is to try out the recipe for ourselves.
0:18:23 > 0:18:25So, "Peel large potatoes.
0:18:25 > 0:18:30"Cut it into little slices about a quarter of an inch thick."
0:18:30 > 0:18:32- Lard to go in there.- Yeah.
0:18:33 > 0:18:35"Put it on a quick fire."
0:18:35 > 0:18:37A fairly hot fire.
0:18:39 > 0:18:41They look like they're cooking nice.
0:18:41 > 0:18:43They've gone pale, they're rising to the top.
0:18:43 > 0:18:45- Excellent.- Bubbling like crazy.
0:18:45 > 0:18:48"Keep moving them till they are crisp."
0:18:48 > 0:18:50Oh, that's puffing up a little bit there.
0:18:50 > 0:18:51Smells lovely.
0:18:51 > 0:18:54"Take them up and let them drain in your sieve."
0:18:57 > 0:19:00OK. "A very little salt sprinkled over them."
0:19:02 > 0:19:04- Yeah.- They smell like crisps, don't they?- They do, yeah.
0:19:10 > 0:19:11It looks like a crisp.
0:19:11 > 0:19:13It smells like a crisp.
0:19:13 > 0:19:14It tastes like a crisp.
0:19:14 > 0:19:16That is a crisp.
0:19:19 > 0:19:22So, would you say that the invention of the crisp
0:19:22 > 0:19:26is definitely before the American story?
0:19:26 > 0:19:32Certainly. If you do this recipe, you produce fried slices of potatoes
0:19:32 > 0:19:33that are certainly crisp.
0:19:34 > 0:19:38'So it looks like us Brits really did invent the crisp.'
0:19:48 > 0:19:50Back at our factory in Leicester,
0:19:50 > 0:19:52our potatoes have been cleaned and peeled
0:19:52 > 0:19:54and are now heading for the knife.
0:19:56 > 0:19:59The first step is to make sure they're all the right size.
0:20:01 > 0:20:03So, what we've got here are our potatoes
0:20:03 > 0:20:07and they're getting presented across the top of this screw deck.
0:20:07 > 0:20:10And as you can see, the smaller ones are falling through,
0:20:10 > 0:20:13they don't need cutting, they're already the right size.
0:20:13 > 0:20:15But there's a few that are coming through.
0:20:15 > 0:20:19They're a little bit bigger and they are heading for the guillotine.
0:20:19 > 0:20:22So, we're going to cut those potatoes in half.
0:20:22 > 0:20:26So the French peasant small potatoes are falling through the holes,
0:20:26 > 0:20:28the aristocracy is going across here
0:20:28 > 0:20:30to meet Madame Guillotine.
0:20:31 > 0:20:33Can you tell in a bag of crisps
0:20:33 > 0:20:36whether you have got crisps that come from a hole or a cut potato?
0:20:36 > 0:20:38I'm going to let you into a secret,
0:20:38 > 0:20:40which is if you look at those crisps,
0:20:40 > 0:20:44if it's got a straight edge, it's been halved on a machine like this.
0:20:44 > 0:20:46- I'll have a look when I get home. - Very good.
0:20:46 > 0:20:49So, now we've got the right size, are they going to be sliced?
0:20:49 > 0:20:50We're ready to slice.
0:20:50 > 0:20:53How long have you got left? You've got about 20 odd minutes left.
0:20:59 > 0:21:02Next, my spuds take the conveyor belt
0:21:02 > 0:21:05up to some of the fastest potato slicers on earth.
0:21:05 > 0:21:10Inside these machines there is a drum spinning at very high speed.
0:21:10 > 0:21:12When the potatoes are dropped into the drum,
0:21:12 > 0:21:15the centrifugal force flings them to the outside
0:21:15 > 0:21:19where an average potato is cut into 45 slices
0:21:19 > 0:21:21in around 0.2 of a second.
0:21:23 > 0:21:25Wow. That's unbelievable!
0:21:27 > 0:21:31It's all done by eight hardened steel razor blades
0:21:31 > 0:21:36which constantly need changing and that job falls to Sudhir Raval.
0:21:37 > 0:21:39That's incredibly ingenious.
0:21:39 > 0:21:41As that spins really fast, the potatoes...
0:21:41 > 0:21:44- They stay on the outside of the drum.- That's right.
0:21:44 > 0:21:46And as they turn round, they slice... Wow.
0:21:46 > 0:21:49'There are 33 slicers throughout this factory
0:21:49 > 0:21:53'and they get through almost 2,000 blades every day.'
0:21:53 > 0:21:56You never actually touch the blade, you use the magnet.
0:21:56 > 0:21:59I want to be the razor blade salesman here.
0:22:04 > 0:22:07- Can I check my slices? - Yes, we can do.
0:22:07 > 0:22:08I've done a good job there.
0:22:10 > 0:22:11The slices are constantly checked
0:22:11 > 0:22:15to make sure they're being cut to precisely the right thickness.
0:22:18 > 0:22:19Then they're off.
0:22:19 > 0:22:21Racing down a giant river of potato.
0:22:24 > 0:22:28I love this. I want to ride down this in a kayak.
0:22:30 > 0:22:33Now, the water you can see here is milky
0:22:33 > 0:22:35and that's because it contains starch.
0:22:35 > 0:22:37The starch has come out of the action of cutting the slice
0:22:37 > 0:22:40Water taking the starch out.
0:22:40 > 0:22:43Another spray of water to wash more starch out,
0:22:43 > 0:22:46another bath to get the starch out and another spray
0:22:46 > 0:22:49and that is to stop them being so starchy
0:22:49 > 0:22:51that they stick together as a clump. Is that right?
0:22:51 > 0:22:53Absolutely right.
0:22:53 > 0:22:55I can guarantee they are the right thickness.
0:22:55 > 0:22:57I've been up there changing the blades and measuring them.
0:22:59 > 0:23:01What you can see here, they go through the hairdryer
0:23:01 > 0:23:04and what we are looking for is
0:23:04 > 0:23:06we talk about the slices dancing a little bit.
0:23:06 > 0:23:07So they're bouncing around
0:23:07 > 0:23:10and that means there's just the right amount of air pressure
0:23:10 > 0:23:12to just dry that slice out just enough.
0:23:14 > 0:23:17Now my slices are ready to be fried.
0:23:17 > 0:23:20The factory has seven mammoth industrial fryers
0:23:20 > 0:23:22running 24 hours a day.
0:23:22 > 0:23:25They're filled with a blend of rapeseed oil
0:23:25 > 0:23:29and sunflower oil trucked in from southern Europe.
0:23:29 > 0:23:33All major crisp manufacturers in the UK now use sunflower oil
0:23:33 > 0:23:38instead of traditional cooking oil as it contains less saturated fat.
0:23:38 > 0:23:41What temperature? Am I allowed to ask?
0:23:41 > 0:23:43So, it's around 180 degrees C
0:23:43 > 0:23:45but we will move that up a little bit
0:23:45 > 0:23:47and down a little bit according to the potato.
0:23:47 > 0:23:51So, we'll make adjustments to the temperature and also to the time.
0:23:51 > 0:23:54It's around three minutes but we'll adjust it
0:23:54 > 0:23:55according to the product.
0:23:55 > 0:23:58So, those potatoes, that I watched come in,
0:23:58 > 0:24:00you will adjust the temperature
0:24:00 > 0:24:05- to cook those differently to the others?- Exactly right.
0:24:05 > 0:24:09As they fry, the water inside our potato slices is boiled off
0:24:09 > 0:24:11and replaced with some of that oil.
0:24:12 > 0:24:17An individual bag of crisps has just over half a tablespoon of oil in it,
0:24:17 > 0:24:19which means these fryers are getting through
0:24:19 > 0:24:22tens of thousands of litres of oil a day
0:24:22 > 0:24:25and need to be topped up continuously.
0:24:27 > 0:24:30That is the most crisps I have ever seen in one place
0:24:30 > 0:24:32and I've been to a few parties.
0:24:32 > 0:24:35- These haven't got a flavour on yet, have they? Nothing.- Nothing at all.
0:24:35 > 0:24:37This is pure unadulterated crisp.
0:24:37 > 0:24:40I've never had a pure unadulterated crisp.
0:24:40 > 0:24:42Would you like to go fishing for crisps?
0:24:45 > 0:24:49- I'm going to test your knowledge. What's special about that crisp?- Oh!
0:24:49 > 0:24:50That's been cut. Yes!
0:24:50 > 0:24:52You've been paying attention.
0:24:52 > 0:24:54Hot crisps.
0:24:55 > 0:24:57You've never tasted better.
0:24:59 > 0:25:00Lovely crunch.
0:25:02 > 0:25:04Needs a little bit of salt, mate.
0:25:04 > 0:25:07I don't suppose you've thought of that.
0:25:09 > 0:25:12While my crisps cool down ready for the next stage,
0:25:12 > 0:25:14Cherry is on a very different type of production line
0:25:14 > 0:25:16making a very different type of snack.
0:25:19 > 0:25:22The vast majority of crisps are shaped like this
0:25:22 > 0:25:26because they are sliced from a potato. Simple.
0:25:26 > 0:25:30But how do you get a savoury snack in the shape of an alien head
0:25:30 > 0:25:32or a rasher of bacon
0:25:32 > 0:25:35or a twig or a bear or...
0:25:36 > 0:25:39I don't even know what that's supposed to be. Mm.
0:25:39 > 0:25:42More than a third of savoury snacks consumed in the UK
0:25:42 > 0:25:45are actually made from a grain called maize
0:25:45 > 0:25:48or, as we more commonly know it, corn.
0:25:51 > 0:25:55This factory in Lancashire turns 96 tonnes of corn
0:25:55 > 0:26:00into 12 million Monster Munch snacks every 24 hours.
0:26:00 > 0:26:02The man in charge is Ian Rigby.
0:26:04 > 0:26:07Once the corn has been picked from the field, what happens to it?
0:26:07 > 0:26:10It's dried and then it's smashed up into little pieces.
0:26:10 > 0:26:12What else goes into this?
0:26:12 > 0:26:15We add the other ingredient, which is water.
0:26:15 > 0:26:19So this is just made out of corn and water. That's it?
0:26:19 > 0:26:22- That's it.- That sounds really easy.
0:26:22 > 0:26:24How we do it, it's a bit like magic.
0:26:29 > 0:26:31This is the extruder.
0:26:31 > 0:26:33You put the raw ingredients in at one end
0:26:33 > 0:26:36and then the extruder does a number of things.
0:26:36 > 0:26:41It mixes all of the ingredients together, it then cooks it
0:26:41 > 0:26:46and then puts it under an immense amount of pressure down at this end.
0:26:46 > 0:26:49The extruder is like a giant pressure cooker.
0:26:49 > 0:26:53Inside, steel screws push the ingredients from one end to another
0:26:53 > 0:26:58cooking, compressing and mixing them into a gloopy paste as they go.
0:26:58 > 0:27:03Then it's squeezed under immense pressure through precision moulds
0:27:03 > 0:27:07called dies to create the shape of the finished snack.
0:27:07 > 0:27:10So, they are forced through these tiny holes
0:27:10 > 0:27:13in the shape of a tiny foot.
0:27:13 > 0:27:16- Would you like to see one? - I would love to see one.
0:27:16 > 0:27:19- Well, it's top secret. I'm so sorry.- What?!
0:27:20 > 0:27:22That's so unfair.
0:27:22 > 0:27:25- But I can show you something similar.- OK. That will do.
0:27:26 > 0:27:28- Do you see how small they are?- Yes.
0:27:28 > 0:27:32And these two make circles and crosses.
0:27:32 > 0:27:35- If we take a look, that sits on there.- Yes.
0:27:35 > 0:27:38So, that snack is obviously significantly larger
0:27:38 > 0:27:41than the hole it came out from. How?
0:27:41 > 0:27:44When it hits atmosphere, it expands and holds its shape
0:27:44 > 0:27:48into a perfectly formed cross, circle
0:27:48 > 0:27:50or, in fact, a monster's foot.
0:27:52 > 0:27:54As the mixture is forced out of the die,
0:27:54 > 0:27:58a series of blades rotate 16 times a second
0:27:58 > 0:28:01to cut it into the finished shapes.
0:28:01 > 0:28:06That's how it's supposed to work but I can't help wondering...
0:28:06 > 0:28:09If you took the cutter away,
0:28:09 > 0:28:12would the mixture just continue to propel out,
0:28:12 > 0:28:16would you just get one massive monster foot?
0:28:16 > 0:28:18After some persuasion,
0:28:18 > 0:28:22Ian and a team of engineers have offered to take the cutter off
0:28:22 > 0:28:24to give me a close up look.
0:28:24 > 0:28:26- I've never seen this before.- Are you nervous?
0:28:26 > 0:28:29- I'm very nervous. - I'm a bit nervous too.
0:28:30 > 0:28:32Here we go. Whey.
0:28:32 > 0:28:34Whoa!
0:28:34 > 0:28:36Oh, my God.
0:28:36 > 0:28:39Whoa!
0:28:39 > 0:28:42'Four dies are sending out an endless strip
0:28:42 > 0:28:44'of hot, compressed corn.'
0:28:47 > 0:28:49The world's longest monster foot.
0:28:49 > 0:28:51That is coming out so quickly
0:28:51 > 0:28:53- and at such high pressure. - Watch you fingers.
0:28:53 > 0:28:56It's really strong.
0:28:56 > 0:28:58Can you still see the shape of the foot?
0:28:58 > 0:29:00So, before I saw a monster foot,
0:29:00 > 0:29:03but I think now I'm seeing the whole monster.
0:29:03 > 0:29:05I feel like the monster is trying to escape.
0:29:08 > 0:29:12I'm a bit worried we're going to disrupt the nation's supply of
0:29:12 > 0:29:16foot-shaped snacks, so the cutting head goes back on
0:29:16 > 0:29:18and it's back up to full speed -
0:29:18 > 0:29:21over 8,000 monster feet a minute.
0:29:23 > 0:29:25That is unbelievably fast.
0:29:25 > 0:29:27It's really mesmerising to watch.
0:29:27 > 0:29:29I could watch it all day.
0:29:31 > 0:29:36Then it's simply a matter of heating them to remove the water,
0:29:36 > 0:29:39seasoning with a secret recipe mixed in oil
0:29:39 > 0:29:41and packing them.
0:29:43 > 0:29:48As we speak, hundreds of odd shapes are flying off factory lines
0:29:48 > 0:29:49all around the country.
0:29:49 > 0:29:53So, whether you like your snacks in a square shape or a star shape
0:29:53 > 0:29:55or even with toes,
0:29:55 > 0:30:00it's all thanks to some pretty impressive precision engineering.
0:30:08 > 0:30:13Back in Leicester, we're a little over four hours into the process.
0:30:13 > 0:30:14My crisps have just come out of the fryer
0:30:14 > 0:30:16and before they can be seasoned,
0:30:16 > 0:30:18they have to be inspected.
0:30:18 > 0:30:21Every single one of them.
0:30:21 > 0:30:24Tell me how you can look at every single crisp.
0:30:24 > 0:30:27Inside here you can see the bright light
0:30:27 > 0:30:31and we have a digital camera which is inspecting every single crisp
0:30:31 > 0:30:32passing the crossing.
0:30:32 > 0:30:34How fast is that going?
0:30:34 > 0:30:38That machine is handling 450 crisps every second.
0:30:38 > 0:30:42And then the machine is making a decision to say, "Yes, it's good,"
0:30:42 > 0:30:46or, "No, I'm going to reject it."
0:30:46 > 0:30:49It's using a fine jet of compressed air...
0:30:49 > 0:30:51Hang on, hang on, hang on.
0:30:51 > 0:30:56At 450 crisps a second, the machine is taking photographs
0:30:56 > 0:31:01and then directing a jet of air to knock them off the production line?
0:31:01 > 0:31:03Exactly right.
0:31:03 > 0:31:05I can see the crisps dropping
0:31:05 > 0:31:07but they look like they're just falling.
0:31:07 > 0:31:12They're actually being knocked off by a computer-directed jet of air.
0:31:12 > 0:31:14That's James Bond, that is.
0:31:14 > 0:31:17Is there any evil genius sitting somewhere that devices all this?
0:31:17 > 0:31:19Is he's stroking a white cat?
0:31:19 > 0:31:20HE CHUCKLES
0:31:20 > 0:31:22So, this is all about colour.
0:31:22 > 0:31:25So, it's looking for a colour that you wouldn't want in the bag.
0:31:25 > 0:31:27'As Cherry discovered earlier,
0:31:27 > 0:31:29'if a potato contains too much sugar,
0:31:29 > 0:31:32'that sugar will caramelise as it's fried
0:31:32 > 0:31:35'giving the crisps a brown colour.'
0:31:35 > 0:31:37But it's kind of not fair, is it?
0:31:37 > 0:31:40Because some farmers' batch of potatoes
0:31:40 > 0:31:43might have less reject crisps than others
0:31:43 > 0:31:45or am I getting, like, too pernickety?
0:31:45 > 0:31:49Well, we would love all our farmers to produce great quality
0:31:49 > 0:31:50so we recognise that.
0:31:50 > 0:31:53So, for the best potatoes, we pay a quality bonus.
0:31:53 > 0:31:56So every batch of potatoes that come in, mine as well,
0:31:56 > 0:31:59all right, everybody gets...the farmer knows what he's going to get
0:31:59 > 0:32:01but if they get less rejects, they get a bit more?
0:32:01 > 0:32:04Exactly. Because we're making a few more bags of crisps.
0:32:04 > 0:32:06I bet mine were perfect. You can pay me in cash.
0:32:12 > 0:32:17My potato slices have been dried, fried and scrutinised
0:32:17 > 0:32:21and now they're finally ready to be flavoured.
0:32:23 > 0:32:27They travel on a system of vibrating conveyors -
0:32:27 > 0:32:31which is the only way to move crisps quickly without breaking them -
0:32:31 > 0:32:36and eventually arrive at one of 23 giant seasoning drums.
0:32:37 > 0:32:39Welcome to seasoning.
0:32:41 > 0:32:45That aroma is instantly recognisable
0:32:45 > 0:32:49to anyone who's ever opened a bag of cheese and onion crisps.
0:32:49 > 0:32:51It is quite incredible.
0:32:51 > 0:32:53What's happening exactly?
0:32:53 > 0:32:56What you can see before you is this drum
0:32:56 > 0:33:00and what we're using the drum to do is to gently tumble those crisps
0:33:00 > 0:33:02so that we get a perfect coating of the seasoning
0:33:02 > 0:33:04on both sides of the crisp.
0:33:04 > 0:33:07Well, you can see behind, we've got a powder.
0:33:07 > 0:33:09So we're dropping it, sprinkling it across the crisp.
0:33:09 > 0:33:12So, when I open a packet of crisps,
0:33:12 > 0:33:18what percentage of it now is potato and what percentage is seasoning?
0:33:18 > 0:33:19What's the ratio?
0:33:19 > 0:33:21Well, in the case of cheese and onion,
0:33:21 > 0:33:26we put about 6% of cheese and onion seasoning on our crisps.
0:33:27 > 0:33:30I love the fact... Can you kneel a little bit?
0:33:30 > 0:33:34Cos I like having my crisps served on a silver tray still warm.
0:33:39 > 0:33:43That's a flavour and a texture that I've actually grown up with.
0:33:43 > 0:33:46You know what I fancy now though, don't you? A pint of beer.
0:33:46 > 0:33:50The time between now and getting them in a bag must be crucial.
0:33:50 > 0:33:54Absolutely. So, from here to a bag is only about three minutes.
0:33:54 > 0:33:57It's a crisp superhighway, isn't it?
0:33:59 > 0:34:03They get through more than 450 boxes of seasoning
0:34:03 > 0:34:05every day in this place.
0:34:05 > 0:34:08It's all made off site by large seasoning houses.
0:34:08 > 0:34:12But what surprised me is that almost every new crisp flavour
0:34:12 > 0:34:16this factory comes up with starts off as a real dish,
0:34:16 > 0:34:19cooked by a real chef here in the factory.
0:34:19 > 0:34:23Ben Barlow is in charge of the development kitchen.
0:34:23 > 0:34:25He's invited me in to taste some of the dishes
0:34:25 > 0:34:29his team are cooking up as they develop new crisp flavours.
0:34:29 > 0:34:31A lot of the flavour actually is the batter.
0:34:31 > 0:34:35'I'm helping him develop a new cheesy beans on toast flavour.'
0:34:35 > 0:34:36Make one that you want to eat
0:34:36 > 0:34:39- and I'll make one that I think the public will want to eat.- All right.
0:34:39 > 0:34:42- What are they, chef? - They are home-made ones.
0:34:42 > 0:34:45I want to put a little bit of parmigiano on it.
0:34:45 > 0:34:48It can take over a year to develop and launch a new flavour.
0:34:48 > 0:34:51It all starts with Ben and his team cooking up dozens,
0:34:51 > 0:34:53sometimes hundreds, of variations
0:34:53 > 0:34:57and then trying to identify the subtle flavour difference
0:34:57 > 0:34:59in each one.
0:35:00 > 0:35:03We want you to start breaking it down, and that's what we do here.
0:35:03 > 0:35:05We break it down into each of its taste components
0:35:05 > 0:35:07and then try and recreate that on a crisp.
0:35:07 > 0:35:10You actually start thinking about cheesy beans on toast,
0:35:10 > 0:35:11it's quite complex.
0:35:13 > 0:35:15Just describe to me the flavour journey.
0:35:15 > 0:35:17So, what are you getting first?
0:35:17 > 0:35:19What's starting to come through second?
0:35:19 > 0:35:22For me, first of all, the unmistakable smokiness of paprika.
0:35:22 > 0:35:27Then, after that, straightaway we're into the fruity richness,
0:35:27 > 0:35:29almost sweetness, of the beans.
0:35:29 > 0:35:32Yours did have a cheese flavour, mine didn't.
0:35:32 > 0:35:36'Once Ben's decided which version of cheesy beans on toast is right,
0:35:36 > 0:35:40'he then needs to have that flavour produced on an industrial scale
0:35:40 > 0:35:44'by Europe's largest seasoning houses.
0:35:44 > 0:35:47'But first, he has to describe the specific taste
0:35:47 > 0:35:48'he wants them to create.'
0:35:48 > 0:35:51I want to say, "Right, I want to taste the beans first,
0:35:51 > 0:35:53"I then want some toast and butter coming through
0:35:53 > 0:35:55"and then I want it to finish with cheese."
0:35:56 > 0:35:58At the seasoning house,
0:35:58 > 0:36:01a team of food scientists use a complex combination
0:36:01 > 0:36:05of mainly natural and some processed ingredients
0:36:05 > 0:36:07to match the flavour Ben's described.
0:36:07 > 0:36:09Once they've got it right,
0:36:09 > 0:36:11it's produced in vast quantities
0:36:11 > 0:36:15in 2.5 tonne mixers and trucked back to the factory
0:36:15 > 0:36:19where, in total, they get through more than 10 tonnes
0:36:19 > 0:36:20of seasoning a day.
0:36:20 > 0:36:24But before Ben's new flavours get anywhere near the public,
0:36:24 > 0:36:29they have to get past a panel of super tasters.
0:36:29 > 0:36:32So, if we taste sample E again.
0:36:32 > 0:36:34- Cheese note there, isn't there?- Mm. - Yeah.
0:36:34 > 0:36:36It feels like black pepper.
0:36:36 > 0:36:39- There's no burn, is there? - That's quite smoky.
0:36:39 > 0:36:43Every day, a group of hand-picked specialist crisp tasters
0:36:43 > 0:36:45meet to sample new flavours
0:36:45 > 0:36:49and check the existing ones are up to scratch.
0:36:50 > 0:36:52So, I'm getting umami on this one.
0:36:52 > 0:36:53Any onion there?
0:36:53 > 0:36:56- Yes, onion.- There's onion definitely.
0:36:56 > 0:36:57- Yeah.- It's sweet as well.
0:36:59 > 0:37:02I'm dying to join them but first...
0:37:03 > 0:37:06..I have to pass the official taste test
0:37:06 > 0:37:08to see if I've got what it takes.
0:37:08 > 0:37:10- Are you ready to begin?- I am. I certainly am.
0:37:10 > 0:37:12This could be embarrassing.
0:37:14 > 0:37:16Am I smelling this?
0:37:18 > 0:37:20That's sweet. That's like vanilla.
0:37:20 > 0:37:22Here's your second one.
0:37:22 > 0:37:23Marzipan.
0:37:23 > 0:37:25You're not going to give me the answers, are you?
0:37:25 > 0:37:28I feel under such pressure here.
0:37:29 > 0:37:31Orange.
0:37:31 > 0:37:32Pine.
0:37:33 > 0:37:35These are subtle.
0:37:36 > 0:37:37Salt.
0:37:38 > 0:37:41That grows. It's almost musty.
0:37:42 > 0:37:44Can I have some whisky?
0:37:44 > 0:37:47That's slightly more bitter.
0:37:47 > 0:37:49Sour. Sour.
0:37:49 > 0:37:51Almost getting towards a citrus flavour.
0:37:52 > 0:37:55Oh. Ta-ra. Glad we had this chat.
0:37:55 > 0:37:58'Matt Cullingworth is the man in charge.'
0:37:58 > 0:38:00- So, we've got your scores on the doors.- Really?
0:38:00 > 0:38:03- Yeah. You did phenomenally well. - Seriously?- Yeah, absolutely.
0:38:03 > 0:38:07You did a phenomenal job. So, on the aromas you got four of them correct.
0:38:07 > 0:38:10- Very descriptive as well. - I like you, mate.
0:38:10 > 0:38:13And then on your basic tastes, all of them correct.
0:38:14 > 0:38:17- You don't know how relieved I am, honestly.- Yeah.
0:38:17 > 0:38:19Would you employ me as a super taster?
0:38:19 > 0:38:20You can have a job now, Gregg.
0:38:20 > 0:38:23- Yeah!- Congratulations. - Honestly, it makes me really happy.
0:38:23 > 0:38:25Can you imagine how bad that would've looked if I didn't?
0:38:25 > 0:38:28Well, John Torode might have had a few words to say, mightn't he?
0:38:28 > 0:38:30Yeah.
0:38:30 > 0:38:34Phew. Fortunately for my career, I've passed the taste test,
0:38:34 > 0:38:37so I'm allowed to rub shoulders with the super tasters.
0:38:37 > 0:38:40- Hello, guys.- Hi, there. - Mind if I join you?
0:38:40 > 0:38:41Not at all.
0:38:41 > 0:38:45- What are we doing?- We are looking at developing a new flavour today.
0:38:45 > 0:38:48R&D want some feedback, so let's get straight into it.
0:38:48 > 0:38:50If we taste sample A first.
0:38:52 > 0:38:55- I'm getting quite a strong tangy note.- Cheese.
0:38:55 > 0:38:58That's definitely cheese, but that's quite mild
0:38:58 > 0:39:00and it hasn't got the tang of a cheddar.
0:39:00 > 0:39:03OK, so, what are the key differences between samples A and B?
0:39:03 > 0:39:05- The heat note.- Spices.
0:39:05 > 0:39:07You're right, it's got a spice finish.
0:39:07 > 0:39:09- Stays on your tongue.- You're right.
0:39:09 > 0:39:11- It's got a rancid note, too. - It has got rancid.
0:39:11 > 0:39:15- There is a sourness, isn't there? - Dairy sour.- Dairy sour.
0:39:15 > 0:39:16What, like curd?
0:39:16 > 0:39:19It's a bit like baby sick. That butyric acid sort of thing.
0:39:19 > 0:39:21Well, either you've tasted baby sick
0:39:21 > 0:39:23or you were a baby a little while ago.
0:39:23 > 0:39:26I mean, I don't know how you're getting that.
0:39:26 > 0:39:29'Any new flavour, even a new potato variety,
0:39:29 > 0:39:33'has got to get the OK from this team before it goes any further.
0:39:33 > 0:39:36'So, there are some very influential tongues in this room.'
0:39:36 > 0:39:40- Is this your job? - This is my only job, yeah.
0:39:40 > 0:39:42And are you proud when you go to a party
0:39:42 > 0:39:45- and people want to know what you do? - I am very proud, yes.
0:39:45 > 0:39:48Is there any chance your palates can kind of, like, run out?
0:39:48 > 0:39:51- They can change.- As you get older, your taste buds change, definitely.
0:39:51 > 0:39:54So, the guys are monitored constantly to make sure
0:39:54 > 0:39:57that they can still taste at the highest possible level.
0:39:57 > 0:39:59Thanks for your years of service,
0:39:59 > 0:40:02but I'm afraid your palate is all washed out.
0:40:02 > 0:40:04We've got you a watch. THEY LAUGH
0:40:04 > 0:40:06We were going to have a party, but what's the point?
0:40:06 > 0:40:08You can't taste the food.
0:40:08 > 0:40:11These professional tasters are able to identify
0:40:11 > 0:40:12the most subtle of flavours,
0:40:12 > 0:40:14but, as Cherry is discovering,
0:40:14 > 0:40:19our experience of food depends on a lot more than just taste.
0:40:22 > 0:40:25Have you ever wondered why fish and chips taste so much better
0:40:25 > 0:40:27by the seaside,
0:40:27 > 0:40:32why a whisky always tastes better by the fire
0:40:32 > 0:40:35or why wine you drink in France just doesn't taste as good
0:40:35 > 0:40:37when you get home?
0:40:40 > 0:40:43Charles Spence is professor of Experimental Psychology
0:40:43 > 0:40:44at Oxford University
0:40:44 > 0:40:47and his research has helped uncover the answers.
0:40:48 > 0:40:51I'm hoping you can tell me why fish and chips
0:40:51 > 0:40:54taste so much better by the seaside.
0:40:54 > 0:40:57Our brain, all the time, is picking up information from around us
0:40:57 > 0:40:59and using it to infer what we think we're tasting
0:40:59 > 0:41:00and how much we think we're enjoying it.
0:41:00 > 0:41:03So, if we're eating those fish and chips by the seaside,
0:41:03 > 0:41:06then you've got to imagine there's the smell of the salty sea air,
0:41:06 > 0:41:07maybe the sound of the seagulls
0:41:07 > 0:41:10making the leap that the sea is just there, that fish is fresher.
0:41:10 > 0:41:12It's all really happening up here in our head.
0:41:12 > 0:41:16And as your brain combines all the senses and glues them together
0:41:16 > 0:41:18in ways that the science is just starting to reveal.
0:41:20 > 0:41:23Professor Spence uses innovative lab experiments
0:41:23 > 0:41:27to investigate just how our taste is influenced and confused
0:41:27 > 0:41:29by our other senses.
0:41:30 > 0:41:33Now we are going to test them out in the real world to find out
0:41:33 > 0:41:36what happens when we eat crisps.
0:41:36 > 0:41:38Here, in the pubs of a Brighton,
0:41:38 > 0:41:42we've got no shortage of unsuspecting subjects.
0:41:42 > 0:41:45- Would you do us a massive favour and eat crisps?- Yes.
0:41:45 > 0:41:49First, we're going to take away people's sense of smell
0:41:49 > 0:41:52to see if they can still identify the flavour of a beef crisp.
0:41:52 > 0:41:54Can you smell anything?
0:41:54 > 0:41:55- Can you get any...? - HE SNIFFS
0:41:55 > 0:41:57- I can't open my nose. - At all. Perfect.
0:42:00 > 0:42:01What flavour do you think they are?
0:42:03 > 0:42:05- It's really tricky. - HE LAUGHS
0:42:05 > 0:42:07Are they...are they a bit oniony?
0:42:07 > 0:42:09This is so weird.
0:42:11 > 0:42:13What would you say the flavour was?
0:42:13 > 0:42:14Maybe bacon, I think.
0:42:14 > 0:42:15I'd say chicken.
0:42:15 > 0:42:18Cheesy, cheese and onion.
0:42:18 > 0:42:20It tastes just like cardboard, no taste.
0:42:20 > 0:42:21Can you take your nose clip off?
0:42:22 > 0:42:24I know, it's beef and onion.
0:42:25 > 0:42:28- Can you tell the real flavour? - It tastes beefy.
0:42:28 > 0:42:30- Beef, roast beef.- Yes!
0:42:30 > 0:42:33So, did you notice a significant change after you could smell?
0:42:33 > 0:42:35Yeah, it was completely different, yes.
0:42:35 > 0:42:38'No-one we asked could determine the flavour,
0:42:38 > 0:42:41'proof that smell is fundamental to taste.'
0:42:41 > 0:42:42We think we're tasting things,
0:42:42 > 0:42:45we experience the taste of the crisp in our mouth, but, in fact,
0:42:45 > 0:42:47maybe as much as 75% to 95% of what we think we're tasting
0:42:47 > 0:42:49is really coming from the nose.
0:42:49 > 0:42:52Every time you swallow, a little bit of the volatile aromas
0:42:52 > 0:42:53that we've made in our mouth
0:42:53 > 0:42:56are kind of pushed out of the back of the nose.
0:42:56 > 0:43:00- Yes.- And that is what we think of as taste but it's really smell.
0:43:02 > 0:43:05The next surprising experiment aims to show
0:43:05 > 0:43:10that our enjoyment of crisps can be somehow influenced by what we hear.
0:43:10 > 0:43:12I'm going to get you to put some headphones on.
0:43:12 > 0:43:14Can we convince people that identical crisps
0:43:14 > 0:43:16have different crunchiness?
0:43:16 > 0:43:18Close your eyes and put your hand out
0:43:18 > 0:43:19and we'll give you the first one.
0:43:19 > 0:43:23They need to rate the crunchiness on a scale of 1 to 100.
0:43:23 > 0:43:25- 60 maybe.- 60?
0:43:25 > 0:43:2650?
0:43:26 > 0:43:28On the second identical crisp,
0:43:28 > 0:43:32Professor Spence now uses a computer to increase the volume
0:43:32 > 0:43:36of the high-pitched sounds in the crisps crunch
0:43:36 > 0:43:38being fed into the headphones.
0:43:38 > 0:43:42- I think crunchier.- Crunchier. - How much crunchier?
0:43:42 > 0:43:45Hmm, quite a bit.
0:43:45 > 0:43:46So maybe a 90.
0:43:46 > 0:43:50- That's crispier, I think. About 90. - OK. 90?
0:43:50 > 0:43:51- 90.- 90.
0:43:51 > 0:43:53Like, an 80 or 90.
0:43:53 > 0:43:56Ooh, so significantly crispier.
0:43:56 > 0:43:59Are you surprised to know that both of those crisps
0:43:59 > 0:44:04are from the same packet, both exactly the same freshness?
0:44:04 > 0:44:08I thought I knew a lot about crisps but obviously not.
0:44:08 > 0:44:12Professor Spence's studies show on average subjects believe
0:44:12 > 0:44:16it's around 15% crunchier when the sound is manipulated.
0:44:16 > 0:44:17It did make a big difference.
0:44:17 > 0:44:22The noise crisps make when you eat them gives our brain information.
0:44:22 > 0:44:25Subconsciously we associate the crispier crisps
0:44:25 > 0:44:27with being more appetising.
0:44:27 > 0:44:29We think we're tasting the crunchiness between our teeth
0:44:29 > 0:44:32and in our mouth, but in fact, all the time our brain is picking up
0:44:32 > 0:44:35the sounds of crunch or crackle and those sounds are very informative
0:44:35 > 0:44:37about what we're actually tasting.
0:44:37 > 0:44:39Every time we crunch into something, our ears hear those sounds
0:44:39 > 0:44:42and depending on the frequency spectrum, how loud the crunch,
0:44:42 > 0:44:46we use that to infer how crisp, how fresh the food is.
0:44:46 > 0:44:50Lastly we want to see how much our sense of taste is influenced
0:44:50 > 0:44:51by what we see.
0:44:52 > 0:44:55Can people detect the flavour of a crisp
0:44:55 > 0:44:57when it's in a different bag?
0:44:57 > 0:44:59Professor Spence has a blue bag,
0:44:59 > 0:45:01the most common colour for cheese and onion
0:45:01 > 0:45:04but he's filled it with salt and vinegar crisps.
0:45:04 > 0:45:06What's the flavour?
0:45:06 > 0:45:07- Cheese and onion.- OK.
0:45:07 > 0:45:11Would you be surprised to know it was, in fact, salt and vinegar?
0:45:11 > 0:45:13- No way.- Yes.
0:45:13 > 0:45:15- Well, I thought, "Oh, blue bag, cheese and onion."- Yes.
0:45:15 > 0:45:17- "It must be cheese and onion." - Yes, definitely.
0:45:19 > 0:45:22When we do this in the lab, we get exactly the same response.
0:45:22 > 0:45:24Our brain sees a packet, expects one thing,
0:45:24 > 0:45:26tastes something different and gets confused
0:45:26 > 0:45:28when the colours and the flavours don't match.
0:45:28 > 0:45:31So, what you're seeing is incredibly important
0:45:31 > 0:45:33to how you experience the taste.
0:45:33 > 0:45:34Absolutely.
0:45:34 > 0:45:39From these experiments, it's clear that smell, sound and sight
0:45:39 > 0:45:41are critical to our taste.
0:45:41 > 0:45:43So, next time you eat a crisp,
0:45:43 > 0:45:47stop to think about how many different senses are influencing
0:45:47 > 0:45:49your enjoyment of it.
0:45:49 > 0:45:52Or not. You gave me a stale one.
0:46:03 > 0:46:06It's been less than four and a half hours
0:46:06 > 0:46:09since my potatoes were sitting on the farm in Hampshire.
0:46:09 > 0:46:13They've been peeled, fried, seasoned
0:46:13 > 0:46:16and now they just need to go in a bag,
0:46:16 > 0:46:20which presents the next challenge for this factory.
0:46:20 > 0:46:23How do you fill a bag with an exact weight
0:46:23 > 0:46:26when no two crisps are identical?
0:46:26 > 0:46:30The answer lies in one of the craziest rooms I've seen.
0:46:48 > 0:46:50Julie Biddles is responsible for filling
0:46:50 > 0:46:53hundreds of thousands of bags of crisps an hour.
0:46:54 > 0:46:58- This is quite an extraordinary room. - Yeah. Very good, isn't it?
0:46:58 > 0:47:02I don't think anybody ever would have seen anything quite like it.
0:47:02 > 0:47:03Ever.
0:47:03 > 0:47:06- How many of these things are there in here?- There's 118.
0:47:06 > 0:47:09118 of these individual...
0:47:09 > 0:47:13And tell me, is each one of these little buckets with the numbers,
0:47:13 > 0:47:16- is each one of these a bag of crisps?- No.
0:47:16 > 0:47:17It's a weighing machine
0:47:17 > 0:47:21and it will use three to four combinations to make one bag
0:47:21 > 0:47:25but you might have a little bit in each one to make up the 25g.
0:47:25 > 0:47:27Inside this little bucket now it's being weighed
0:47:27 > 0:47:32and then a computer will choose a combination of four of these
0:47:32 > 0:47:33to make up one bag.
0:47:33 > 0:47:35Whichever the best combination is to make that weight.
0:47:35 > 0:47:38And the computer will quickly add up how many of those buckets make
0:47:38 > 0:47:40a 25g bag and shoot them down.
0:47:40 > 0:47:4430 milliseconds it takes to calculate the weight
0:47:44 > 0:47:45and then it will drop it.
0:47:45 > 0:47:49- Every time we hear a click, that's another bag of crisps.- That's a bag.
0:47:53 > 0:47:57And people must be eating them at the same pace as you're making them.
0:47:57 > 0:48:01So, every second, a bag of crisps is being eaten.
0:48:02 > 0:48:04And you've got over 100 machines here.
0:48:05 > 0:48:07That's...
0:48:09 > 0:48:1124 hours a day, seven days a week.
0:48:14 > 0:48:17We are a serious nation of crisp munchers, aren't we?
0:48:20 > 0:48:21Have you been here a while?
0:48:21 > 0:48:24Only a little while, 32 years.
0:48:24 > 0:48:27What keeps a nice lady making crisps for over 30 years?
0:48:27 > 0:48:30Job satisfaction.
0:48:30 > 0:48:32I like working with the people that work here,
0:48:32 > 0:48:34they are very, very friendly. We're like a family.
0:48:34 > 0:48:36My mother was in the business before me.
0:48:36 > 0:48:39- So you're a chip off the old block? - Yeah.
0:48:43 > 0:48:44The instant they are weighed,
0:48:44 > 0:48:46the crisps drop through the bottom of the machines
0:48:46 > 0:48:49into waiting bags below
0:48:49 > 0:48:53and it's all happening hundreds of times a second.
0:48:54 > 0:48:57This is the biggest crisp maker in Britain
0:48:57 > 0:48:58but that wasn't always the case.
0:48:58 > 0:49:01In fact, the humble potato crisp
0:49:01 > 0:49:04has been the subject of some fierce battles over the years.
0:49:07 > 0:49:11These days we take for granted that we can buy a packet of crisps
0:49:11 > 0:49:13from any corner shop anywhere in the country,
0:49:13 > 0:49:16but it wasn't always that way.
0:49:16 > 0:49:18I've come to meet crisp historian Steve Berry
0:49:18 > 0:49:24in a North London pub to find out just how crisps went mainstream.
0:49:24 > 0:49:25Steve, there's a really good reason
0:49:25 > 0:49:27why we've met in this pub, isn't there?
0:49:27 > 0:49:30Yes, this is one of the pubs
0:49:30 > 0:49:36that Frank Smith first sold his crisps in around 1920.
0:49:36 > 0:49:38And that's Frank Smith of Smith's Crisps?
0:49:38 > 0:49:41Yeah. Well, at the time, Frank Smith was a grocer's assistant.
0:49:41 > 0:49:44He, with his wife, set up in a garage,
0:49:44 > 0:49:46little cottage industry, producing them.
0:49:46 > 0:49:48And he would take them out on his pony and trap
0:49:48 > 0:49:52to lots of different pubs in the North London area.
0:49:54 > 0:49:57'Smith's Crisps were so successful with the pub crowd
0:49:57 > 0:49:59'that he soon set up a proper factory.
0:49:59 > 0:50:03'His business grew exponentially through the 1920s
0:50:03 > 0:50:05'and he became the leading crisp manufacturer
0:50:05 > 0:50:07'in London and the south-east.
0:50:09 > 0:50:11'And by the 1950s,
0:50:11 > 0:50:15'other regional crisp manufacturers had sprung up around the country.
0:50:16 > 0:50:19'But because crisps had such a short shelf life,
0:50:19 > 0:50:23'they could only sell to local shops and pubs.'
0:50:23 > 0:50:24So, if you were in the Midlands,
0:50:24 > 0:50:27you likely would have had only Walkers.
0:50:27 > 0:50:29If you were in Scotland, Golden Wonder,
0:50:29 > 0:50:31and Newcastle would be Tudor Crisps
0:50:31 > 0:50:33or Northern Ireland would be Taytos.
0:50:35 > 0:50:37But all that changed in the 1960s,
0:50:37 > 0:50:39when the greased paper bags they were sold in
0:50:39 > 0:50:42were replaced with cellophane bags.
0:50:43 > 0:50:46They increased shelf life from a few days to many months
0:50:46 > 0:50:48and meant regional brands could now expand
0:50:48 > 0:50:51into each other's territories.
0:50:51 > 0:50:53From the early 1960s it was war.
0:50:53 > 0:50:57The emphasis changed from the speed and volume of production
0:50:57 > 0:51:00and started to be much more about the innovation in terms of flavour.
0:51:00 > 0:51:04Throughout the '60s and '70s, the swinging decades,
0:51:04 > 0:51:07you just had all kinds of weird and wonderful flavours
0:51:07 > 0:51:09suddenly started to saturate the market.
0:51:09 > 0:51:11Nothing but the best for you. Right, lad?
0:51:11 > 0:51:13Aye, great flavours, Tudor.
0:51:13 > 0:51:16For over a century, crisps had only been salted.
0:51:16 > 0:51:19Now the sky was the limit for flavour
0:51:19 > 0:51:21and the public loved it.
0:51:21 > 0:51:23These are my "flavourite" crisps.
0:51:23 > 0:51:24Flavourite?
0:51:27 > 0:51:31- I see you brought loads of old crisp packets with you.- Yes.
0:51:31 > 0:51:34This is a breadth of different flavours
0:51:34 > 0:51:38that were tried throughout the '70s and '80s.
0:51:38 > 0:51:41So, you have Tudor's chocolate flavoured crisps,
0:51:41 > 0:51:44which were considered to be so niche at the time
0:51:44 > 0:51:47that they were marketed only in the Scottish region
0:51:47 > 0:51:49and failed spectacularly.
0:51:49 > 0:51:51Hedgehog crisps, I remember them.
0:51:51 > 0:51:52Yes.
0:51:52 > 0:51:56In actual fact, they are a combination of hedgerow herbs
0:51:56 > 0:51:59and pork fat, hence the hog.
0:51:59 > 0:52:02So, there's something more of pork than porcupine about those ones.
0:52:02 > 0:52:05SHE LAUGHS
0:52:05 > 0:52:08From those early flavour experiments in the '60s, '70s and '80s,
0:52:08 > 0:52:12our love of bizarre crisps continues today.
0:52:12 > 0:52:15You can now buy butter and mint, pastrami,
0:52:15 > 0:52:18even gin and tonic flavoured crisps.
0:52:18 > 0:52:22But, so far, hedgehog hasn't made a comeback.
0:52:33 > 0:52:37I wouldn't have believed this was possible if I hadn't seen it myself,
0:52:37 > 0:52:38but less than 30 minutes
0:52:38 > 0:52:41since my potatoes were sitting on the back of a truck,
0:52:41 > 0:52:44they're now crisps in a bag.
0:52:44 > 0:52:46But before that bag is sealed,
0:52:46 > 0:52:49there's one last surprising thing to be added.
0:52:49 > 0:52:52So, is that air you've pumped into there then?
0:52:52 > 0:52:56What we've got inside the bag there is nitrogen.
0:52:56 > 0:52:57That keeps it fresh.
0:52:57 > 0:52:59Really?
0:52:59 > 0:53:01There's two main constituents of air.
0:53:01 > 0:53:04One is oxygen - fantastic, it keeps you alive,
0:53:04 > 0:53:06but it's the enemy of food.
0:53:06 > 0:53:08It would make our crisps go stale.
0:53:08 > 0:53:11The other thing, which is the majority of air,
0:53:11 > 0:53:12is a thing called nitrogen.
0:53:12 > 0:53:14We put nitrogen in the bag
0:53:14 > 0:53:17and that's the reason you get that fresh taste
0:53:17 > 0:53:19every time you open a packet.
0:53:19 > 0:53:23Every bag of crisps is a bag of nitrogen, is that right?
0:53:23 > 0:53:27It's a bag of crisps full of nitrogen.
0:53:27 > 0:53:29I'm taking for granted that's safe, right?
0:53:29 > 0:53:31Perfectly safe. It's all around us.
0:53:31 > 0:53:34- So, oxygen deteriorates food, right? I get that.- Got it.
0:53:34 > 0:53:38But nitrogen doesn't, it will kind of keep it in suspended animation.
0:53:38 > 0:53:41Stable, yeah. It preserves it for longer.
0:53:41 > 0:53:44What would happen if you didn't flush nitrogen through?
0:53:44 > 0:53:47What would happen, do you think, if you just flushed air into it?
0:53:47 > 0:53:49'To try and answer this question,
0:53:49 > 0:53:53'Simon's got two bags of crisps, both three months old.'
0:53:53 > 0:53:55Do you think I will know the difference?
0:53:55 > 0:53:58'One is a standard bag that was filled with nitrogen
0:53:58 > 0:54:00'and the other was filled with normal air
0:54:00 > 0:54:02'to see if I can spot the difference.'
0:54:10 > 0:54:13There's not a great deal of discernible difference.
0:54:13 > 0:54:16The best way to tell is using your nose.
0:54:18 > 0:54:20- There's a difference. There's a difference.- Much...
0:54:20 > 0:54:22There's a difference in the smell, most certainly.
0:54:22 > 0:54:25That, actually, that one does smell of oil.
0:54:27 > 0:54:29And that one smells of cheese and onion.
0:54:29 > 0:54:31But they're both crisp.
0:54:31 > 0:54:33I mean, they're both crisp and they both taste OK.
0:54:33 > 0:54:37But I'll give you it, that one smells of oil.
0:54:37 > 0:54:38Well, we're passionate about crisps.
0:54:38 > 0:54:41We notice the difference and we care about the difference.
0:54:43 > 0:54:46As well as helping to preserve the crisps,
0:54:46 > 0:54:49the nitrogen also acts as a cushion
0:54:49 > 0:54:52to protect them on their journey to the shop's shelf.
0:54:53 > 0:54:55It's been less than four and a half hours
0:54:55 > 0:54:58since I saw the spuds being loaded into a truck
0:54:58 > 0:55:01and now my crisps are heading for distribution.
0:55:01 > 0:55:05They've got to move more than five million bags of crisps
0:55:05 > 0:55:07all over this gigantic site every day,
0:55:07 > 0:55:10so forget about conveyor belts.
0:55:13 > 0:55:16Welcome to the crisp monorail.
0:55:21 > 0:55:24This computer-controlled system snakes through
0:55:24 > 0:55:26the factory's distribution centre
0:55:26 > 0:55:29connecting the packing hall with the loading bay.
0:55:31 > 0:55:34The distribution centre is monstrous,
0:55:34 > 0:55:37more than 37,000 square metres,
0:55:37 > 0:55:40larger than the Houses of Parliament.
0:55:40 > 0:55:42And from the control room,
0:55:42 > 0:55:45Chris Neville can track every single packet.
0:55:45 > 0:55:47From this nerve centre here,
0:55:47 > 0:55:50we can see all the pallets moving around the site,
0:55:50 > 0:55:52which ones are going to which customers
0:55:52 > 0:55:53and we can also track the vehicles.
0:55:53 > 0:55:57This truck is going to a customer and do you see the blue arrows?
0:55:57 > 0:56:00It should arrive in about 40 minutes.
0:56:00 > 0:56:03The trucks not only deliver crisps to supermarkets,
0:56:03 > 0:56:08many will also then collect potatoes on the way back to the factory
0:56:08 > 0:56:11and Chris knows where they are at every stage.
0:56:11 > 0:56:13So just take a potato, right?
0:56:13 > 0:56:18One potato, from the moment it leaves that farm's gate,
0:56:18 > 0:56:19all the way down to here,
0:56:19 > 0:56:22and then through every process
0:56:22 > 0:56:25and then back out again as a cooked and flavoured crisp,
0:56:25 > 0:56:29all the way out to the shop where I can buy it,
0:56:29 > 0:56:32you track it minute by minute.
0:56:32 > 0:56:33Correct, yes.
0:56:33 > 0:56:35George Orwell predicted this.
0:56:36 > 0:56:39On average, a truck loaded with crisps
0:56:39 > 0:56:43will leave this distribution centre every six minutes.
0:56:43 > 0:56:47From the factory in Leicester, they will be delivered all over the UK,
0:56:47 > 0:56:50where the biggest crisp eaters are in the north-east.
0:56:50 > 0:56:53And amazingly, some will even make it to the Costa del Sol
0:56:53 > 0:56:55to satisfy the expat market.
0:56:56 > 0:57:00Raw potatoes that were on a farm just this morning
0:57:00 > 0:57:03could be being eaten as crisps as soon as tomorrow.
0:57:05 > 0:57:06It is quite remarkable
0:57:06 > 0:57:10that you can put a simple potato in one end of a factory
0:57:10 > 0:57:13and it will come out as a sealed, flavoured bag of crisps
0:57:13 > 0:57:16the other end of the factory in just 35 minutes.
0:57:16 > 0:57:20Not only that, the engineering and the precision that you need
0:57:20 > 0:57:24to do it five million times a day.
0:57:24 > 0:57:26But do you know what really surprises me?
0:57:26 > 0:57:29It's that we actually eat that many crisps.
0:57:29 > 0:57:32Right. I've done my training,
0:57:32 > 0:57:36the only thing left is to load my crisps on the back of a truck.
0:57:39 > 0:57:40Chocks away, Ginger!
0:57:56 > 0:57:57'Next time...'
0:57:57 > 0:57:59That's a tin of beans, isn't it?
0:57:59 > 0:58:04'..we'll take you inside the largest baked bean factory in the world...'
0:58:04 > 0:58:06A billion beans is going to go through here.
0:58:06 > 0:58:09'..revealing the secrets to making three million cans a day.'
0:58:09 > 0:58:10That is mega strong.
0:58:10 > 0:58:13That is simply that with ripples in it.
0:58:13 > 0:58:17'And Cherry feels the heat at the epic steelworks
0:58:17 > 0:58:19'where your tin can begins.'
0:58:19 > 0:58:23It's so hot bits of it are just falling off.
0:58:23 > 0:58:26What it takes to give us beans on toast, hey.