Crisps Inside the Factory

We are a nation of snackers.

Over the next 24 hours, we will get through half a billion crisps.

That takes over 17 million potatoes a day

grown and harvested on UK farms like this one in Hampshire.

Tonight, we'll reveal just what it takes to produce crisps

on such a mind-boggling scale.

As we give you a rare look inside the largest crisp factory on earth.

'I'm Gregg Wallace.'

Bring her in.

'And tonight I'll join the race to keep up with demand

'for our favourite snack.'

That's a packet of crisps?

HE LAUGHS How does it do it that fast?

'I'll meet the super tasters testing every new flavour.'

-There is a sourness, isn't there?

-What, like curd?

It's a bit like baby sick.

'And reveal the tricks this factory uses to keep your crisps fresh.'

In every bag of crisps is a bag of nitrogen?

'I'm Cherry Healey.'

That smells really good.

'And I'll discover the secrets of the perfect crisp potato.'

Why are they so dark?

Because they have a lot of sugar which has caramelised.

'And the surprising ways your brain can be tricked

'into tasting something that's not there.'

-It's really tricky.

-I thought I knew a lot about crisps.

'Historian Ruth Goodman uncovers who really invented the crisp.'

We are going to have to rethink crisp history.

I love this. I want to ride down this in a kayak.

'We spend more on crisps than anywhere else in Europe.'

Every day over five million packets of crisps

fly out of this one factory.

It's an incredible feat of logistics and engineering.

You'll never look at a humble packet of crisps in the same way again.

Welcome to Inside The Factory.

This is Walker's in Leicester,

the biggest crisp factory in the world.

The crisp has gone through something of a gourmet revolution

over the last few years and you can now get all sorts of posh flavours

from langoustine and lemon

to white stilton and cranberry relish.

But tonight, we are following the nation's biggest seller -

cheese and onion.

Which is a bit of a disappointment to me

because I'm very much a prawn cocktail man.

More than 40% of the crisps eaten in Britain

come out of this one factory.

It runs around the clock, seven days a week.

But whether they are making ready salted

or something a bit more exotic,

the 24-hour production process begins on the farm

with the right spud.

Almost all crisp produced in the UK are made with British potatoes.

The most popular varieties are Markies, Lady Rosetta and Hermes.

The process of making our crisps starts here

on the Hampshire potato farm of Gavin Janaway

whose family have been growing crisp spuds since the 1970s.

These will be going to the crisp factory later on today.

Have they just been dug or have they been in store?

No, these have been in store now for about six months.

We keep them at the right temperature, the right humidity

with fresh air going in there

because a potato is a living, breathing thing.

You know, we've got to try and keep it happy and keep it warm

so it produces a good crisp.

How do you know when they're growing in the ground

that they are going to be perfect for the crisp? You can't tell.

Well, to try and help us tell, Gregg,

we've got our own little frying facility on site here,

our little potato lab.

And we take samples from the field throughout the growing season

and throughout the storage season and we take them to there,

we test them and we actually fry them ourselves.

So, I do my own little MasterChef, a little cooking myself,

with a little bit of salt and pepper - just the right seasoning.

We test them to make sure they're right for the factory.

If they're not ready when we fry them at the field, we just give them

another couple of weeks and a bit of sunshine and everything

-will help them mature.

-At any one time, Gavin could be storing

as many as 160 million potatoes on his farm.

When they get the order through from the factory,

the potatoes are fed into one end of a production line

which can sort, wash and load 27 tonnes of spuds

onto a truck in less than 45 minutes.

Here we go. A nice big crate of British spuds.

How long before that lovely spud becomes a cheese and onion crisp?

That could be a cheese and onion crisp within six hours.

This is where our crisp production line starts.

So, we're now just looking for anything that's green

or has got damage on it or maybe a little shoot on it,

anything that may affect the quality.

-So, take the sprouts out.

-Something like this.

This is damage that's been done through harvesting

so that's mechanical damage. That comes out.

-There's another one.

-That comes out.

Yeah, you won't beat him, he's too quick. He's the fastest one here.

Nobody beats Gregosh.

It doesn't surprise me the best one here is called Greg.

How often are you set up like this?

This is set up all year round

so we can load any day of the week all year round.

Ay, a green one! I got that before Gregosh.

How many potatoes on a lorry load?

There's 27 tonnes

so I think that works out roughly 200,000 packets of crisps

in one lorry load.

-How many lorries go out?

-A busy day would be ten lorries.

So that means on a busy day you send out two million bags of crisps.

Yeah.

This is a Hermes potato.

Over 300 million of these are grown in Britain every year

but you won't ever have seen one in the supermarket

because, as Cherry is finding out, to make crisps,

you need a very specific potato.

I have to admit, I find potato shopping a little bit daunting.

There are so many different varieties

and I never know which one to buy.

In fact, there are more than 230 varieties of potato grown in the UK.

About half of those will end up in your produce aisle

but the other varieties are used

to make everything from frozen waffles to vodka.

But which variety makes the perfect crisps?

To find out, I'm heading to potato HQ,

the National Agronomy Centre in Cambridge,

where James Fowler is a spud expert.

-Ready to go in?

-Ready to go.

-Here we go.

We're going to have a crisp fry up

but with three very different varieties of potato.

I've brought some Maris Peers,

a waxy new potato great for salads,

some King Edwards, a more floury potato perfect for mashing

and James has got this one.

You won't have seen this one, Cherry,

it's a specialist crisping variety we're investigating at the moment.

-We think it's going to make good crisps.

-It's brand-new?

-Yeah, it's...

-It's a revolutionary potato.

'The first obvious difference is the shape.'

Crisping varieties should be predominantly round.

Not long like this Maris Peer.

If they're too small, the crisps are too small

and the bags look half empty

and also there's a lot more peeling waste when you process them.

But the differences are more than skin deep.

When it comes to making crisps,

there are three key parts of a potato -

water, which makes up about 80% of the average spud,

starch and tiny amounts of natural sugar.

Using a hydrometer, you can tell how much water there is.

My two potatoes are about 80% water

but a good crisp potato has only 75%.

The less water, the better

because you need to get rid of almost all of it to make a crisp.

Now the fun bit.

'Now we fry all three potatoes in exactly the same way.'

The water is boiling off.

-And that's what's causing all this steam?

-That's right.

If there's more water in a potato,

when it goes to the factory, you get more steam...

And fewer crisps.

And that's not what you want if you're making crisps.

'But when it comes to making light, golden crisps

'on an industrial scale, the biggest enemy is sugar.'

Wow.

Why are they so dark?

Because they have a lot of sugar which has caramelised

and produced the dark colour.

'The King Edwards have less sugar and so are noticeably lighter.

'Finally, we fry the specialist crisp potatoes

'at the same temperature as the other two.

'Not only do they cook much faster, they look completely different.'

-They look better.

-Wow. So those are much more familiar.

Less sugar.

-Less sugar.

-Less sugar, there's no colour development.

The subtle differences of potatoes

might not matter much if you're just having a fry up at home

but for the nation's biggest crisp makers

making tens of millions of them every day,

the science of spuds is everything.

Mmm.

The potatoes I helped load at the farm

have made the three-hour journey from Hampshire

to the factory in Leicester.

Where factory manager Simon Devaney is ready and waiting.

Come on, bring her in.

How many potatoes have we got on there, do you know?

There's about 200,000 potatoes on average.

And how many trucks like that come in every day?

We get about 25 every single day, 24 hours a day.

So, that's about five million potatoes every day.

How many potatoes in one standard packet of crisps?

Well, we're using about five million potatoes every day

and we're making about five million packets every day.

-That's a packet of crisps?

-That's a packet of crisps.

That's a packet of crisps?

Five million potatoes in, five million bags of crisps out.

Dead right.

I love this. I absolutely love this.

'My first job is to climb aboard and collect a sample.'

Righto, they make lovely chips, tell your mum.

Guaranteed to bake or fry, make a pudding or a pie.

Call me a saint, call me sinner, call it a tenner.

Then we conduct the same test Cherry did in the lab

to measure the exact water content in this truck load of spuds.

Understanding the solids content of the potato

is absolutely critical.

The amount of water in that potato is going to vary through the year

and if we know that,

it ensures we can make the right quality of crisp consistently.

Every batch of potatoes is going to be slightly different, right?

That's right.

And you will adjust the heat,

adjust the cooking temperature of the potato

depending on what the potatoes are on every lorry load.

-Every single load.

-Now what?

This product is good. Let's start making some crisps.

Potatoes are much more delicate than they might seem

and can easily bruise.

So, the best way to get 200,000 spuds off a lorry?

Float them off.

Fire her up! Let's go!

Ay! That's a fair amount of water there, old son.

They basically flood the compartment of the truck

and the potatoes just come out with the water.

Exactly right.

But that now is a very wet potato.

I mean, that is going to start to deteriorate.

You can't keep potatoes in water.

No. So, time is of the essence

but in 35 minutes, it's going to be in a packet of crisps.

What?

35 minutes.

Just over half an hour and you turn that into crisps.

That can't happen.

I can't make chips in that time.

This potato, this one here, just to make sure, right,

is going to be a packet of cheese and onion crisps in 35 minutes.

35 minutes.

OK. Your time starts right now.

-I'll see that in just over half an hour's time...

-Yeah.

..in a little blue bag.

When you're dealing with five million potatoes a day,

you need an efficient way of peeling them.

And here, in the world's biggest crisp factory,

they have to peel more than 2,000 every minute.

To do that, you need some hard-core potato peelers.

We're using a thing called abrasion peeling here.

Something that your grandma might actually have had in her kitchen.

We're spinning the potatoes round against a rough surface,

a little bit like sandpaper, and just removing a small amount of

that peel to leave a clean potato ready for the next process.

That's quite an aggressive rumble.

-You cannot only see it, you can feel it under your feet.

-Yeah.

You've got potatoes coming in all year.

-That's right.

-All year.

-The thickness of the skin is going to change.

-Yeah.

You're a greengrocer, so you know this stuff.

So, a new potato that you might have with your salad in the summer

has got a very light skin,

that's the same for the crisps as well.

So we need to handle that much more gently

by giving it a very light peel, five or ten seconds,

versus that one in the springtime, which is more like a jacket potato,

that's going to take a little bit longer.

How do you know you've peeled them all properly?

Because even if I do half a bag of potatoes,

sometimes I might miss a bit.

We've got a whole series of digital cameras here

and they are looking at every single potato.

-It photographs every single one?

-Every single one.

To the side here, you can see what looks a little bit like

a piano keyboard, a series of fingers.

If we get a bad potato coming through,

you'll hear a gust of air

and that will kick that potato out, that will be rejected.

That's a bit nuts, mate.

HE LAUGHS How does it do it that fast?

My potato is about to be sliced and fried and turned into a crisp.

A process that will be repeated five million times today.

But who first did it? Who invented the crisp?

That's a question Ruth Goodman is trying to answer.

And it's not as simple as it sounds.

If you speak to Americans,

they will tell you that they invented the crisp in 1853.

And that it's down to a man called George Crum,

a chef who was working in a country club in New York State.

And the story goes that the chef Crum

had a particularly difficult customer,

a wealthy industrialist, who kept sending his chips back

saying they weren't thin enough.

George got so fed up in the end that he decided to make the chips

so thin that they would be inedible and then he covered them in salt.

Much to his surprise, the customer loved them.

So much so, that he put them on the menu.

But for me, there's something fishy about this story.

We've been cooking potatoes for 200 years before

the Americans claimed to have invented the crisp.

Surely we'd come up with a similar recipe before then.

To get to the bottom of this mystery

and find out once and for all who invented the crisp,

I'm meeting food historian Regina Sexton to plot the history

of the humble crisp.

The potato is in England by the 1580s, the 1590s,

is looked upon as an exotic thing.

So, something desirable, a plant for people to have in their gardens.

Gradually, potatoes moved from being just a specimen plant

to become something that we started to eat

and by the 18th century, they had become the staple of the Irish poor.

Soon they were eating an astonishing 12 to 14 pounds per person per day.

I can hardly even lift that.

-That is a huge amount of potato.

-It is.

-But that's it. That's the only thing you eat all day?

-Yeah.

As Britain's population exploded in the 19th century,

the potato became a culinary mainstay.

One of the most popular Victorian cookery books was

William Kitchener's The Cook's Oracle,

first published in 1817.

-This book, in fact, was a bestseller in its day.

-Oh, really?

I love this, "The vegetable kingdom affords no food more wholesome,

"more easily procured, easily prepared

"or less expensive than the potato."

'It's packed with potato recipes

'including one that's quite familiar.'

"Potatoes fried in slices or shavings."

Now, that's a really interesting recipe if you read through it.

"Fry them in lard or dripping

-"and keep moving them until they are crisp."

-Crisp.

-What date did you say this was?

-1817.

1817.

So, that's quite a bit before 1853

-when the Americans say they invented the crisp, isn't it?

-Yes, it is.

So, if we cook this and it really turns out to be a crisp,

then we are going to have to rethink crisp history.

I think we might have to.

The only way to find out if this really is

the very first recipe for crisps,

36 years before it was claimed that George Crum invented them

in America, is to try out the recipe for ourselves.

So, "Peel large potatoes.

"Cut it into little slices about a quarter of an inch thick."

-Lard to go in there.

-Yeah.

"Put it on a quick fire."

A fairly hot fire.

They look like they're cooking nice.

They've gone pale, they're rising to the top.

-Excellent.

-Bubbling like crazy.

"Keep moving them till they are crisp."

Oh, that's puffing up a little bit there.

Smells lovely.

"Take them up and let them drain in your sieve."

OK. "A very little salt sprinkled over them."

-Yeah.

-They smell like crisps, don't they?

-They do, yeah.

It looks like a crisp.

It smells like a crisp.

It tastes like a crisp.

That is a crisp.

So, would you say that the invention of the crisp

is definitely before the American story?

Certainly. If you do this recipe, you produce fried slices of potatoes

that are certainly crisp.

'So it looks like us Brits really did invent the crisp.'

Back at our factory in Leicester,

our potatoes have been cleaned and peeled

and are now heading for the knife.

The first step is to make sure they're all the right size.

So, what we've got here are our potatoes

and they're getting presented across the top of this screw deck.

And as you can see, the smaller ones are falling through,

they don't need cutting, they're already the right size.

But there's a few that are coming through.

They're a little bit bigger and they are heading for the guillotine.

So, we're going to cut those potatoes in half.

So the French peasant small potatoes are falling through the holes,

the aristocracy is going across here

to meet Madame Guillotine.

Can you tell in a bag of crisps

whether you have got crisps that come from a hole or a cut potato?

I'm going to let you into a secret,

which is if you look at those crisps,

if it's got a straight edge, it's been halved on a machine like this.

-I'll have a look when I get home.

-Very good.

So, now we've got the right size, are they going to be sliced?

We're ready to slice.

How long have you got left? You've got about 20 odd minutes left.

Next, my spuds take the conveyor belt

up to some of the fastest potato slicers on earth.

Inside these machines there is a drum spinning at very high speed.

When the potatoes are dropped into the drum,

the centrifugal force flings them to the outside

where an average potato is cut into 45 slices

in around 0.2 of a second.

Wow. That's unbelievable!

It's all done by eight hardened steel razor blades

which constantly need changing and that job falls to Sudhir Raval.

That's incredibly ingenious.

As that spins really fast, the potatoes...

-They stay on the outside of the drum.

-That's right.

And as they turn round, they slice... Wow.

'There are 33 slicers throughout this factory

'and they get through almost 2,000 blades every day.'

You never actually touch the blade, you use the magnet.

I want to be the razor blade salesman here.

-Can I check my slices?

-Yes, we can do.

I've done a good job there.

The slices are constantly checked

to make sure they're being cut to precisely the right thickness.

Then they're off.

Racing down a giant river of potato.

I love this. I want to ride down this in a kayak.

Now, the water you can see here is milky

and that's because it contains starch.

The starch has come out of the action of cutting the slice

Water taking the starch out.

Another spray of water to wash more starch out,

another bath to get the starch out and another spray

and that is to stop them being so starchy

that they stick together as a clump. Is that right?

Absolutely right.

I can guarantee they are the right thickness.

I've been up there changing the blades and measuring them.

What you can see here, they go through the hairdryer

and what we are looking for is

we talk about the slices dancing a little bit.

So they're bouncing around

and that means there's just the right amount of air pressure

to just dry that slice out just enough.

Now my slices are ready to be fried.

The factory has seven mammoth industrial fryers

running 24 hours a day.

They're filled with a blend of rapeseed oil

and sunflower oil trucked in from southern Europe.

All major crisp manufacturers in the UK now use sunflower oil

instead of traditional cooking oil as it contains less saturated fat.

What temperature? Am I allowed to ask?

So, it's around 180 degrees C

but we will move that up a little bit

and down a little bit according to the potato.

So, we'll make adjustments to the temperature and also to the time.

It's around three minutes but we'll adjust it

according to the product.

So, those potatoes, that I watched come in,

you will adjust the temperature

-to cook those differently to the others?

-Exactly right.

As they fry, the water inside our potato slices is boiled off

and replaced with some of that oil.

An individual bag of crisps has just over half a tablespoon of oil in it,

which means these fryers are getting through

tens of thousands of litres of oil a day

and need to be topped up continuously.

That is the most crisps I have ever seen in one place

and I've been to a few parties.

-These haven't got a flavour on yet, have they? Nothing.

-Nothing at all.

This is pure unadulterated crisp.

I've never had a pure unadulterated crisp.

Would you like to go fishing for crisps?

-I'm going to test your knowledge. What's special about that crisp?

-Oh!

That's been cut. Yes!

You've been paying attention.

Hot crisps.

You've never tasted better.

Lovely crunch.

Needs a little bit of salt, mate.

I don't suppose you've thought of that.

While my crisps cool down ready for the next stage,

Cherry is on a very different type of production line

making a very different type of snack.

The vast majority of crisps are shaped like this

because they are sliced from a potato. Simple.

But how do you get a savoury snack in the shape of an alien head

or a rasher of bacon

or a twig or a bear or...

I don't even know what that's supposed to be. Mm.

More than a third of savoury snacks consumed in the UK

are actually made from a grain called maize

or, as we more commonly know it, corn.

This factory in Lancashire turns 96 tonnes of corn

into 12 million Monster Munch snacks every 24 hours.

The man in charge is Ian Rigby.

Once the corn has been picked from the field, what happens to it?

It's dried and then it's smashed up into little pieces.

What else goes into this?

We add the other ingredient, which is water.

So this is just made out of corn and water. That's it?

-That's it.

-That sounds really easy.

How we do it, it's a bit like magic.

This is the extruder.

You put the raw ingredients in at one end

and then the extruder does a number of things.

It mixes all of the ingredients together, it then cooks it

and then puts it under an immense amount of pressure down at this end.

The extruder is like a giant pressure cooker.

Inside, steel screws push the ingredients from one end to another

cooking, compressing and mixing them into a gloopy paste as they go.

Then it's squeezed under immense pressure through precision moulds

called dies to create the shape of the finished snack.

So, they are forced through these tiny holes

in the shape of a tiny foot.

-Would you like to see one?

-I would love to see one.

-Well, it's top secret. I'm so sorry.

-What?!

That's so unfair.

-But I can show you something similar.

-OK. That will do.

-Do you see how small they are?

-Yes.

And these two make circles and crosses.

-If we take a look, that sits on there.

-Yes.

So, that snack is obviously significantly larger

than the hole it came out from. How?

When it hits atmosphere, it expands and holds its shape

into a perfectly formed cross, circle

or, in fact, a monster's foot.

As the mixture is forced out of the die,

a series of blades rotate 16 times a second

to cut it into the finished shapes.

That's how it's supposed to work but I can't help wondering...

If you took the cutter away,

would the mixture just continue to propel out,

would you just get one massive monster foot?

After some persuasion,

Ian and a team of engineers have offered to take the cutter off

to give me a close up look.

-I've never seen this before.

-Are you nervous?

-I'm very nervous.

-I'm a bit nervous too.

Here we go. Whey.

Whoa!

Oh, my God.

Whoa!

'Four dies are sending out an endless strip

'of hot, compressed corn.'

The world's longest monster foot.

That is coming out so quickly

-and at such high pressure.

-Watch you fingers.

It's really strong.

Can you still see the shape of the foot?

So, before I saw a monster foot,

but I think now I'm seeing the whole monster.

I feel like the monster is trying to escape.

I'm a bit worried we're going to disrupt the nation's supply of

foot-shaped snacks, so the cutting head goes back on

and it's back up to full speed -

over 8,000 monster feet a minute.

That is unbelievably fast.

It's really mesmerising to watch.

I could watch it all day.

Then it's simply a matter of heating them to remove the water,

seasoning with a secret recipe mixed in oil

and packing them.

As we speak, hundreds of odd shapes are flying off factory lines

all around the country.

So, whether you like your snacks in a square shape or a star shape

or even with toes,

it's all thanks to some pretty impressive precision engineering.

Back in Leicester, we're a little over four hours into the process.

My crisps have just come out of the fryer

and before they can be seasoned,

they have to be inspected.

Every single one of them.

Tell me how you can look at every single crisp.

Inside here you can see the bright light

and we have a digital camera which is inspecting every single crisp

passing the crossing.

How fast is that going?

That machine is handling 450 crisps every second.

And then the machine is making a decision to say, "Yes, it's good,"

or, "No, I'm going to reject it."

It's using a fine jet of compressed air...

Hang on, hang on, hang on.

At 450 crisps a second, the machine is taking photographs

and then directing a jet of air to knock them off the production line?

Exactly right.

I can see the crisps dropping

but they look like they're just falling.

They're actually being knocked off by a computer-directed jet of air.

That's James Bond, that is.

Is there any evil genius sitting somewhere that devices all this?

Is he's stroking a white cat?

HE CHUCKLES

So, this is all about colour.

So, it's looking for a colour that you wouldn't want in the bag.

'As Cherry discovered earlier,

'if a potato contains too much sugar,

'that sugar will caramelise as it's fried

'giving the crisps a brown colour.'

But it's kind of not fair, is it?

Because some farmers' batch of potatoes

might have less reject crisps than others

or am I getting, like, too pernickety?

Well, we would love all our farmers to produce great quality

so we recognise that.

So, for the best potatoes, we pay a quality bonus.

So every batch of potatoes that come in, mine as well,

all right, everybody gets...the farmer knows what he's going to get

but if they get less rejects, they get a bit more?

Exactly. Because we're making a few more bags of crisps.

I bet mine were perfect. You can pay me in cash.

My potato slices have been dried, fried and scrutinised

and now they're finally ready to be flavoured.

They travel on a system of vibrating conveyors -

which is the only way to move crisps quickly without breaking them -

and eventually arrive at one of 23 giant seasoning drums.

Welcome to seasoning.

That aroma is instantly recognisable

to anyone who's ever opened a bag of cheese and onion crisps.

It is quite incredible.

What's happening exactly?

What you can see before you is this drum

and what we're using the drum to do is to gently tumble those crisps

so that we get a perfect coating of the seasoning

on both sides of the crisp.

Well, you can see behind, we've got a powder.

So we're dropping it, sprinkling it across the crisp.

So, when I open a packet of crisps,

what percentage of it now is potato and what percentage is seasoning?

What's the ratio?

Well, in the case of cheese and onion,

we put about 6% of cheese and onion seasoning on our crisps.

I love the fact... Can you kneel a little bit?

Cos I like having my crisps served on a silver tray still warm.

That's a flavour and a texture that I've actually grown up with.

You know what I fancy now though, don't you? A pint of beer.

The time between now and getting them in a bag must be crucial.

Absolutely. So, from here to a bag is only about three minutes.

It's a crisp superhighway, isn't it?

They get through more than 450 boxes of seasoning

every day in this place.

It's all made off site by large seasoning houses.

But what surprised me is that almost every new crisp flavour

this factory comes up with starts off as a real dish,

cooked by a real chef here in the factory.

Ben Barlow is in charge of the development kitchen.

He's invited me in to taste some of the dishes

his team are cooking up as they develop new crisp flavours.

A lot of the flavour actually is the batter.

'I'm helping him develop a new cheesy beans on toast flavour.'

Make one that you want to eat

-and I'll make one that I think the public will want to eat.

-All right.

-What are they, chef?

-They are home-made ones.

I want to put a little bit of parmigiano on it.

It can take over a year to develop and launch a new flavour.

It all starts with Ben and his team cooking up dozens,

sometimes hundreds, of variations

and then trying to identify the subtle flavour difference

in each one.

We want you to start breaking it down, and that's what we do here.

We break it down into each of its taste components

and then try and recreate that on a crisp.

You actually start thinking about cheesy beans on toast,

it's quite complex.

Just describe to me the flavour journey.

So, what are you getting first?

What's starting to come through second?

For me, first of all, the unmistakable smokiness of paprika.

Then, after that, straightaway we're into the fruity richness,

almost sweetness, of the beans.

Yours did have a cheese flavour, mine didn't.

'Once Ben's decided which version of cheesy beans on toast is right,

'he then needs to have that flavour produced on an industrial scale

'by Europe's largest seasoning houses.

'But first, he has to describe the specific taste

'he wants them to create.'

I want to say, "Right, I want to taste the beans first,

"I then want some toast and butter coming through

"and then I want it to finish with cheese."

At the seasoning house,

a team of food scientists use a complex combination

of mainly natural and some processed ingredients

to match the flavour Ben's described.

Once they've got it right,

it's produced in vast quantities

in 2.5 tonne mixers and trucked back to the factory

where, in total, they get through more than 10 tonnes

of seasoning a day.

But before Ben's new flavours get anywhere near the public,

they have to get past a panel of super tasters.

So, if we taste sample E again.

-Cheese note there, isn't there?

-Mm.

-Yeah.

It feels like black pepper.

-There's no burn, is there?

-That's quite smoky.

Every day, a group of hand-picked specialist crisp tasters

meet to sample new flavours

and check the existing ones are up to scratch.

So, I'm getting umami on this one.

Any onion there?

-Yes, onion.

-There's onion definitely.

-Yeah.

-It's sweet as well.

I'm dying to join them but first...

..I have to pass the official taste test

to see if I've got what it takes.

-Are you ready to begin?

-I am. I certainly am.

This could be embarrassing.

Am I smelling this?

That's sweet. That's like vanilla.

Here's your second one.

Marzipan.

You're not going to give me the answers, are you?

I feel under such pressure here.

Orange.

Pine.

These are subtle.

Salt.

That grows. It's almost musty.

Can I have some whisky?

That's slightly more bitter.

Sour. Sour.

Almost getting towards a citrus flavour.

Oh. Ta-ra. Glad we had this chat.

'Matt Cullingworth is the man in charge.'

-So, we've got your scores on the doors.

-Really?

-Yeah. You did phenomenally well.

-Seriously?

-Yeah, absolutely.

You did a phenomenal job. So, on the aromas you got four of them correct.

-Very descriptive as well.

-I like you, mate.

And then on your basic tastes, all of them correct.

-You don't know how relieved I am, honestly.

-Yeah.

Would you employ me as a super taster?

You can have a job now, Gregg.

-Yeah!

-Congratulations.

-Honestly, it makes me really happy.

Can you imagine how bad that would've looked if I didn't?

Well, John Torode might have had a few words to say, mightn't he?

Yeah.

Phew. Fortunately for my career, I've passed the taste test,

so I'm allowed to rub shoulders with the super tasters.

-Hello, guys.

-Hi, there.

-Mind if I join you?

Not at all.

-What are we doing?

-We are looking at developing a new flavour today.

R&D want some feedback, so let's get straight into it.

If we taste sample A first.

-I'm getting quite a strong tangy note.

-Cheese.

That's definitely cheese, but that's quite mild

and it hasn't got the tang of a cheddar.

OK, so, what are the key differences between samples A and B?

-The heat note.

-Spices.

You're right, it's got a spice finish.

-Stays on your tongue.

-You're right.

-It's got a rancid note, too.

-It has got rancid.

-There is a sourness, isn't there?

-Dairy sour.

-Dairy sour.

What, like curd?

It's a bit like baby sick. That butyric acid sort of thing.

Well, either you've tasted baby sick

or you were a baby a little while ago.

I mean, I don't know how you're getting that.

'Any new flavour, even a new potato variety,

'has got to get the OK from this team before it goes any further.

'So, there are some very influential tongues in this room.'

-Is this your job?

-This is my only job, yeah.

And are you proud when you go to a party

-and people want to know what you do?

-I am very proud, yes.

Is there any chance your palates can kind of, like, run out?

-They can change.

-As you get older, your taste buds change, definitely.

So, the guys are monitored constantly to make sure

that they can still taste at the highest possible level.

Thanks for your years of service,

but I'm afraid your palate is all washed out.

We've got you a watch. THEY LAUGH

We were going to have a party, but what's the point?

You can't taste the food.

These professional tasters are able to identify

the most subtle of flavours,

but, as Cherry is discovering,

our experience of food depends on a lot more than just taste.

Have you ever wondered why fish and chips taste so much better

by the seaside,

why a whisky always tastes better by the fire

or why wine you drink in France just doesn't taste as good

when you get home?

Charles Spence is professor of Experimental Psychology

at Oxford University

and his research has helped uncover the answers.

I'm hoping you can tell me why fish and chips

taste so much better by the seaside.

Our brain, all the time, is picking up information from around us

and using it to infer what we think we're tasting

and how much we think we're enjoying it.

So, if we're eating those fish and chips by the seaside,

then you've got to imagine there's the smell of the salty sea air,

maybe the sound of the seagulls

making the leap that the sea is just there, that fish is fresher.

It's all really happening up here in our head.

And as your brain combines all the senses and glues them together

in ways that the science is just starting to reveal.

Professor Spence uses innovative lab experiments

to investigate just how our taste is influenced and confused

by our other senses.

Now we are going to test them out in the real world to find out

what happens when we eat crisps.

Here, in the pubs of a Brighton,

we've got no shortage of unsuspecting subjects.

-Would you do us a massive favour and eat crisps?

-Yes.

First, we're going to take away people's sense of smell

to see if they can still identify the flavour of a beef crisp.

Can you smell anything?

-Can you get any...?

-HE SNIFFS

-I can't open my nose.

-At all. Perfect.

What flavour do you think they are?

-It's really tricky.

-HE LAUGHS

Are they...are they a bit oniony?

This is so weird.

What would you say the flavour was?

Maybe bacon, I think.

I'd say chicken.

Cheesy, cheese and onion.

It tastes just like cardboard, no taste.

Can you take your nose clip off?

I know, it's beef and onion.

-Can you tell the real flavour?

-It tastes beefy.

-Beef, roast beef.

-Yes!

So, did you notice a significant change after you could smell?

Yeah, it was completely different, yes.

'No-one we asked could determine the flavour,

'proof that smell is fundamental to taste.'

We think we're tasting things,

we experience the taste of the crisp in our mouth, but, in fact,

maybe as much as 75% to 95% of what we think we're tasting

is really coming from the nose.

Every time you swallow, a little bit of the volatile aromas

that we've made in our mouth

are kind of pushed out of the back of the nose.

-Yes.

-And that is what we think of as taste but it's really smell.

The next surprising experiment aims to show

that our enjoyment of crisps can be somehow influenced by what we hear.

I'm going to get you to put some headphones on.

Can we convince people that identical crisps

have different crunchiness?

Close your eyes and put your hand out

and we'll give you the first one.

They need to rate the crunchiness on a scale of 1 to 100.

-60 maybe.

-60?

50?

On the second identical crisp,

Professor Spence now uses a computer to increase the volume

of the high-pitched sounds in the crisps crunch

being fed into the headphones.

-I think crunchier.

-Crunchier.

-How much crunchier?

Hmm, quite a bit.

So maybe a 90.

-That's crispier, I think. About 90.

-OK. 90?

-90.

-90.

Like, an 80 or 90.

Ooh, so significantly crispier.

Are you surprised to know that both of those crisps

are from the same packet, both exactly the same freshness?

I thought I knew a lot about crisps but obviously not.

Professor Spence's studies show on average subjects believe

it's around 15% crunchier when the sound is manipulated.

It did make a big difference.

The noise crisps make when you eat them gives our brain information.

Subconsciously we associate the crispier crisps

with being more appetising.

We think we're tasting the crunchiness between our teeth

and in our mouth, but in fact, all the time our brain is picking up

the sounds of crunch or crackle and those sounds are very informative

about what we're actually tasting.

Every time we crunch into something, our ears hear those sounds

and depending on the frequency spectrum, how loud the crunch,

we use that to infer how crisp, how fresh the food is.

Lastly we want to see how much our sense of taste is influenced

by what we see.

Can people detect the flavour of a crisp

when it's in a different bag?

Professor Spence has a blue bag,

the most common colour for cheese and onion

but he's filled it with salt and vinegar crisps.

What's the flavour?

-Cheese and onion.

-OK.

Would you be surprised to know it was, in fact, salt and vinegar?

-No way.

-Yes.

-Well, I thought, "Oh, blue bag, cheese and onion."

-Yes.

-"It must be cheese and onion."

-Yes, definitely.

When we do this in the lab, we get exactly the same response.

Our brain sees a packet, expects one thing,

tastes something different and gets confused

when the colours and the flavours don't match.

So, what you're seeing is incredibly important

to how you experience the taste.

Absolutely.

From these experiments, it's clear that smell, sound and sight

are critical to our taste.

So, next time you eat a crisp,

stop to think about how many different senses are influencing

your enjoyment of it.

Or not. You gave me a stale one.

It's been less than four and a half hours

since my potatoes were sitting on the farm in Hampshire.

They've been peeled, fried, seasoned

and now they just need to go in a bag,

which presents the next challenge for this factory.

How do you fill a bag with an exact weight

when no two crisps are identical?

The answer lies in one of the craziest rooms I've seen.

Julie Biddles is responsible for filling

hundreds of thousands of bags of crisps an hour.

-This is quite an extraordinary room.

-Yeah. Very good, isn't it?

I don't think anybody ever would have seen anything quite like it.

Ever.

-How many of these things are there in here?

-There's 118.

118 of these individual...

And tell me, is each one of these little buckets with the numbers,

-is each one of these a bag of crisps?

-No.

It's a weighing machine

and it will use three to four combinations to make one bag

but you might have a little bit in each one to make up the 25g.

Inside this little bucket now it's being weighed

and then a computer will choose a combination of four of these

to make up one bag.

Whichever the best combination is to make that weight.

And the computer will quickly add up how many of those buckets make

a 25g bag and shoot them down.

30 milliseconds it takes to calculate the weight

and then it will drop it.

-Every time we hear a click, that's another bag of crisps.

-That's a bag.

And people must be eating them at the same pace as you're making them.

So, every second, a bag of crisps is being eaten.

And you've got over 100 machines here.

That's...

24 hours a day, seven days a week.

We are a serious nation of crisp munchers, aren't we?

Have you been here a while?

Only a little while, 32 years.

What keeps a nice lady making crisps for over 30 years?

Job satisfaction.

I like working with the people that work here,

they are very, very friendly. We're like a family.

My mother was in the business before me.

-So you're a chip off the old block?

-Yeah.

The instant they are weighed,

the crisps drop through the bottom of the machines

into waiting bags below

and it's all happening hundreds of times a second.

This is the biggest crisp maker in Britain

but that wasn't always the case.

In fact, the humble potato crisp

has been the subject of some fierce battles over the years.

These days we take for granted that we can buy a packet of crisps

from any corner shop anywhere in the country,

but it wasn't always that way.

I've come to meet crisp historian Steve Berry

in a North London pub to find out just how crisps went mainstream.

Steve, there's a really good reason

why we've met in this pub, isn't there?

Yes, this is one of the pubs

that Frank Smith first sold his crisps in around 1920.

And that's Frank Smith of Smith's Crisps?

Yeah. Well, at the time, Frank Smith was a grocer's assistant.

He, with his wife, set up in a garage,

little cottage industry, producing them.

And he would take them out on his pony and trap

to lots of different pubs in the North London area.

'Smith's Crisps were so successful with the pub crowd

'that he soon set up a proper factory.

'His business grew exponentially through the 1920s

'and he became the leading crisp manufacturer

'in London and the south-east.

'And by the 1950s,

'other regional crisp manufacturers had sprung up around the country.

'But because crisps had such a short shelf life,

'they could only sell to local shops and pubs.'

So, if you were in the Midlands,

you likely would have had only Walkers.

If you were in Scotland, Golden Wonder,

and Newcastle would be Tudor Crisps

or Northern Ireland would be Taytos.

But all that changed in the 1960s,

when the greased paper bags they were sold in

were replaced with cellophane bags.

They increased shelf life from a few days to many months

and meant regional brands could now expand

into each other's territories.

From the early 1960s it was war.

The emphasis changed from the speed and volume of production

and started to be much more about the innovation in terms of flavour.

Throughout the '60s and '70s, the swinging decades,

you just had all kinds of weird and wonderful flavours

suddenly started to saturate the market.

Nothing but the best for you. Right, lad?

Aye, great flavours, Tudor.

For over a century, crisps had only been salted.

Now the sky was the limit for flavour

and the public loved it.

These are my "flavourite" crisps.

Flavourite?

-I see you brought loads of old crisp packets with you.

-Yes.

This is a breadth of different flavours

that were tried throughout the '70s and '80s.

So, you have Tudor's chocolate flavoured crisps,

which were considered to be so niche at the time

that they were marketed only in the Scottish region

and failed spectacularly.

Hedgehog crisps, I remember them.

Yes.

In actual fact, they are a combination of hedgerow herbs

and pork fat, hence the hog.

So, there's something more of pork than porcupine about those ones.

SHE LAUGHS

From those early flavour experiments in the '60s, '70s and '80s,

our love of bizarre crisps continues today.

You can now buy butter and mint, pastrami,

even gin and tonic flavoured crisps.

But, so far, hedgehog hasn't made a comeback.

I wouldn't have believed this was possible if I hadn't seen it myself,

but less than 30 minutes

since my potatoes were sitting on the back of a truck,

they're now crisps in a bag.

But before that bag is sealed,

there's one last surprising thing to be added.

So, is that air you've pumped into there then?

What we've got inside the bag there is nitrogen.

That keeps it fresh.

Really?

There's two main constituents of air.

One is oxygen - fantastic, it keeps you alive,

but it's the enemy of food.

It would make our crisps go stale.

The other thing, which is the majority of air,

is a thing called nitrogen.

We put nitrogen in the bag

and that's the reason you get that fresh taste

every time you open a packet.

Every bag of crisps is a bag of nitrogen, is that right?

It's a bag of crisps full of nitrogen.

I'm taking for granted that's safe, right?

Perfectly safe. It's all around us.

-So, oxygen deteriorates food, right? I get that.

-Got it.

But nitrogen doesn't, it will kind of keep it in suspended animation.

Stable, yeah. It preserves it for longer.

What would happen if you didn't flush nitrogen through?

What would happen, do you think, if you just flushed air into it?

'To try and answer this question,

'Simon's got two bags of crisps, both three months old.'

Do you think I will know the difference?

'One is a standard bag that was filled with nitrogen

'and the other was filled with normal air

'to see if I can spot the difference.'

There's not a great deal of discernible difference.

The best way to tell is using your nose.

-There's a difference. There's a difference.

-Much...

There's a difference in the smell, most certainly.

That, actually, that one does smell of oil.

And that one smells of cheese and onion.

But they're both crisp.

I mean, they're both crisp and they both taste OK.

But I'll give you it, that one smells of oil.

Well, we're passionate about crisps.

We notice the difference and we care about the difference.

As well as helping to preserve the crisps,

the nitrogen also acts as a cushion

to protect them on their journey to the shop's shelf.

It's been less than four and a half hours

since I saw the spuds being loaded into a truck

and now my crisps are heading for distribution.

They've got to move more than five million bags of crisps

all over this gigantic site every day,

so forget about conveyor belts.

Welcome to the crisp monorail.

This computer-controlled system snakes through

the factory's distribution centre

connecting the packing hall with the loading bay.

The distribution centre is monstrous,

more than 37,000 square metres,

larger than the Houses of Parliament.

And from the control room,

Chris Neville can track every single packet.

From this nerve centre here,

we can see all the pallets moving around the site,

which ones are going to which customers

and we can also track the vehicles.

This truck is going to a customer and do you see the blue arrows?

It should arrive in about 40 minutes.

The trucks not only deliver crisps to supermarkets,

many will also then collect potatoes on the way back to the factory

and Chris knows where they are at every stage.

So just take a potato, right?

One potato, from the moment it leaves that farm's gate,

all the way down to here,

and then through every process

and then back out again as a cooked and flavoured crisp,

all the way out to the shop where I can buy it,

you track it minute by minute.

Correct, yes.

George Orwell predicted this.

On average, a truck loaded with crisps

will leave this distribution centre every six minutes.

From the factory in Leicester, they will be delivered all over the UK,

where the biggest crisp eaters are in the north-east.

And amazingly, some will even make it to the Costa del Sol

to satisfy the expat market.

Raw potatoes that were on a farm just this morning

could be being eaten as crisps as soon as tomorrow.

It is quite remarkable

that you can put a simple potato in one end of a factory

and it will come out as a sealed, flavoured bag of crisps

the other end of the factory in just 35 minutes.

Not only that, the engineering and the precision that you need

to do it five million times a day.

But do you know what really surprises me?

It's that we actually eat that many crisps.

Right. I've done my training,

the only thing left is to load my crisps on the back of a truck.

Chocks away, Ginger!

'Next time...'

That's a tin of beans, isn't it?

'..we'll take you inside the largest baked bean factory in the world...'

A billion beans is going to go through here.

'..revealing the secrets to making three million cans a day.'

That is mega strong.

That is simply that with ripples in it.

'And Cherry feels the heat at the epic steelworks

'where your tin can begins.'

It's so hot bits of it are just falling off.

What it takes to give us beans on toast, hey.