Original subtitles

Whether you like to binge on a boxset...

..Or watch the new films on the big screen...

..We all love to watch with some serious snacks.

In fact, we spend almost £4 billion on them every year.

Ooh!

And one of our favourites are these, tortilla chips.

CRUNCHES LOUDLY

Shh!

Here in the UK, we eat seven packets of these tiny triangles every second.

That's a whopping 235.4 million packets a year!

And the best place to see how they're made?

The biggest tortilla chip factory in Europe!

I'm Gregg Wallace.

Let me guess, you're boiling it up?

And I'm following the journey tortilla chips take from kernels...

That is like a cement mixer.

..to cooking...

No, that can't be right.

It is. That CAN'T be right.

..and the spicy coating.

Wow, that's crazy!

I'm Cherry Healey.

Recycling snack packets is a tricky process.

So I'm going in search of the UK's first plastic-free crisp packet.

Just like magic, it's turned to film!

And I'll be learning how to perfect a dip for my chips.

You've got the smooth, delicious, sumptuous guacamole,

and then the fiery hot, crispy tortilla!

That, my friend, is the beginning of a good party.

Absolutely. Cheers! Cheers!

And historian Ruth Goodman...

Those are technically called poking sticks.

..is ironing out the link between corn and our clothes.

So, here's to starch, supporting fashion for 500 years.

This factory produces 730 tonnes of tortilla chips every week!

And we're going to reveal how they make each and every one.

Welcome to Inside The Factory.

This is the Doritos factory, in Coventry.

It covers 21,000 square metres.

That is the size of three football pitches.

They make more than 60,000 tonnes of snacks every year here,

including six flavours of tortilla chips.

But I'm hot on the trail of their UK best-seller,

the 150g sharing bag of Chilli Heatwave.

My spicy snack journey begins at the intake area,

where I'm meeting process specialist Richard Lynch.

Rich! Hi, Gregg, how are you doing?

I'm good, I'm happy. Lovely to meet you.

What is on there? Cos that looks to be like an enormous bag

of mixed nuts. It's 27 tonnes of yellow corn.

That's our main ingredient for our tortilla chips.

Mate, I knew that tortillas were made out of corn.

I just thought it would be like a flour.

No. Only the whole kernels of corn, because it gives the best quality.

Right, OK. How much is on there?

27 tonnes.

Whoa.

Have you any idea how many tortilla chips that would make?

Approximately 14 million tortilla chips.

What, individual ones? Yes.

Where is it from? It's from Spain.

Why from Spain? It's the warm weather in Spain.

It gives it the correct growth rate,

gets it to the right size for what we want to use it for.

It also dries it to the correct moisture in the field

before it's been harvested.

All right. So, what's our first step?

To do a quality check on the corn delivery. How do you do that?

So, we need to take a sample of the corn

before we start the full delivery.

Can I get the sample? Yes.

Just want to put it under the chute. Yep.

Whoa-oh!

Is that enough...?

What do you have to check it, then?

So, we put 100g onto here.

Whoa, look at that!

Like a human scale!

Why do you take a sample and what are you looking for?

We're looking for a perfect kernel of corn.

So, what we don't want is any cracked or broken kernels of corn.

That's because it will affect the quality, because it will uptake

the moisture much quicker than a whole kernel of corn.

Moisture is one of the key parameters that we control

all the way through the following process

to make that quality tortilla chip.

So, you are going to cook these - and because there's a lot

of water involved - if they're cracked, they'll absorb

too much water too quickly?

That's correct. Show me a cracked one, then.

So, there's one there.

Oh, is that one? Yep, that's another one.

Right, OK. Well, there's some in there.

What sort of ratio are we looking for?

We want maximum 5% of cracked and broken.

It's very much the same as if I put big potatoes and small potatoes

in a pot, they're going to cook at different times. Yeah.

You need to have uniform corn.

Yeah. Brilliant!

So, can we unload the lorry? Yeah.

Do you want to start the delivery? Me? Yeah.

Stand back.

Just yank it?

Oh!

Whoa!

And the production of my tortilla chips begins!

It'll take one hour and 30 minutes for 27 tonnes of corn kernels

to be piped into one of the factory's massive 190-tonne silos.

Now, I can't be alone in thinking, when it comes to tortillas,

chips need dips - and the traditional Mexican go-to

is guacamole. But how would you go about making a ton of it?

Cherry has the answer.

I love dips, but...

Holy moley, guacamole is hard to make!

Especially when you need a LOT of it.

So, for some hot tips, I'm heading to Delphi Foods -

one of the largest dip manufacturers in Britain,

where I'm meeting co-owner Stavros Styllis.

Stav, lovely to meet you. Nice to meet you, Cherry.

Now, I know that we're making guacamole today. That's right.

And I can see all sorts of ingredients behind me,

but not an avocado in sight. No.

They're in the fridge, Cherry.

Lead the way. Let's go.

Stav's team makes up to a tonne of guacamole a day,

and the key ingredient arrives in frozen form.

Stav, look, you know more than me,

but that doesn't look like an avocado.

It's frozen avocado pulp.

Oh.

I was expecting to see cratefuls of these.

Why frozen avocado pulp?

Simply, we just wouldn't be able to get fresh avocado,

that amount that we need. So, they get imported from Mexico and Peru

and shelf life is limited - probably turn into mush by the time

they get to us - so we have to go down the frozen route.

It keeps this product fresh, green,

and gives it the shelf life that it needs.

OK, that's a very elegant solution.

It is.

To make a mega batch of 97 kilos of guacamole,

I need 55kg of avocado pulp -

which will gently defrost while I get on with the other ingredients,

starting with coriander.

This is the happiest coriander I have ever seen.

It's so crispy and vibrant.

It's delivered to us every day fresh from Covent Garden Market.

Straight into the chopping machine goes 1.5 kilos

of British-grown coriander.

Here we go. Oh, I can see the blade. There it is.

The smell is amazing! Yes.

It's very fragrant.

For our traditional recipe, we're using 3kg of roughly chopped onions,

1kg of jalapeno peppers and 500g of red chillies.

Does guacamole originate from Mexico?

It actually originates all the way back to the Aztecs.

So, it's the oldest dip in the world, maybe? Yep.

There's one in my fridge that probably is the oldest dip in the world that I need to throw out.

From the 14th century, the Aztecs ruled an empire

across central Mexico for 200 years.

And the first English translation of an Aztec recipe

for guacamole dates back to 1697.

Where does the word "guacamole" come from? What does it mean?

Originally, it's from the Aztecs. "Ahuacamolli".

What does that mean?

"Ahuaca" for avocado and "molli" for sauce.

Avocado sauce! Avocado sauce. Perfect.

But you say it's ahuacamolli. Mm-hm.

I call it guacamole.

Well, the Spanish actually changed that.

Once they took it back to Spain, changed the name to guacamole.

OK, so, in a different accent, changed ahuacamolli to guacamole.

Absolutely, yeah. Amazing!

History sorted - it's time to start making our 650 pots of dip,

starting with the defrosted avocados.

That looks really heavy. Yeah. Can we get some help?

I think we need the muscles. OK. Muscles!

Whack it in!

58 kilos are added to the mixer...

Are you sure we've got enough?

..followed by the super fresh coriander...

Coriander. Star of the show.

..then sour cream, spices and garlic puree.

When did avocados come to Britain?

1960s. There was major confusion, cos people were thinking

it was some kind of a dessert.

I mean, there was a story about a lady who turned it into

some kind of a stewed dessert and served it with custard.

Ugh! So, not good, not good.

Not good! No.

They had to go down the route of giving out leaflets

explaining about how to use avocado pears.

I can't believe they come with an instruction manual.

For my SAVOURY dip, we add onions,

jalapenos, red chillies, oil,

and then Stav's secret weapon... lemon juice.

The lemon preserves the colour.

When you cut open an avocado, it goes brown so fast. Mm-hm.

Lemon juice slows that down?

That's a brilliant tip.

Just like with apples, enzymes in the flesh of avocados

react to oxygen in the air.

Citric acid in the lemon juice acts as an antioxidant

to reduce this annoying browning process.

Last but not least, tomatoes complete the guacamole party in a pot.

So, we're ready? We are ready, absolutely.

OK.

It's blended for a short 45 seconds to retain the texture.

What is Antonio doing? He's tipping, and then setting it back,

and tipping and setting it back.

Just helping to move the product so it gets an even blend.

Well, I guess he's doing his own little salsa.

Woo!

100 kilograms of guacamole made -

and it's time to get the party started.

Another reason to celebrate is that avocados are packed with healthy potassium.

So, there's no way I'm leaving without a chip and dip session.

Why do tortilla chips go so perfectly with guacamole?

You've got the heat from the tortilla chips

and the coolness from the guacamole itself.

You've got the smooth, delicious, sumptuous guacamole,

and then the fiery hot, crispy tortilla!

That, my friend, is the beginning of a good party.

Absolutely. Cheers! Cheers!

Mm!

Back at the factory, my 27 tonnes of corn have been unloaded into silos,

before the kernels are piped into the factory, where they're cleaned

and measured, ready for their transformation to tortillas.

So, I'm heading to the balmy batch cooking area.

Whoa!

Rich, this is tropical hot, mate.

Yeah. No, steamingly hot!

This is our cooking area, Gregg.

I know a bit about cooking, so this should be easy.

This is where we start the nixtamalization process.

The what? Nixtamalization process.

What's nixtamalization?

It's an ancient process that was developed thousands of years ago

in Central America, and we follow that traditional method

to make our tortilla chips.

It's critical to make the correct texture of our tortilla chips.

Mate, I've holidayed all over Mexico and, let me tell you,

the ancient Mayans never, ever had great big steel pots

over three floors like this, and gauges.

We've moved on with technology to recreate the same process, Gregg.

Let me guess. Let me guess, you're boiling it up?

No, we don't boil it because boiling it damages the kernels of corn.

We want to keep them intact.

So, what's happening in here, then?

So, we've got 800 kilos of corn, 1,000 litres of water,

and we add some lime to the process.

Hang on, hang on, hang on. What lime?

So, we add lime to the process,

that's a key part of the nixtamalization.

Lime juice? No.

So, this is an alkaline solution.

Why do you add that?

It breaks down the pericarp.

The pericarp is the tough outer shell of the kernel

protecting the soft corn inside,

which contains protein and the essential starch

that will help it absorb moisture for the tortilla dough.

So, when the corn first came to site, it was around 15% moisture.

We need to now increase the moisture at this stage to around 40%.

We need that pericarp removed to allow us to achieve that.

And you do that with a lime solution?

Lime solution and the cooking process.

The Mayans and Aztecs made their lime solution

by heating up limestone and ash in water.

Richard uses calcium hydroxide - a food grade, odourless compound

which helps to break down the corn during cooking.

So, then do you bring the temperature up once you've done that? Yeah.

So, we increase the temperature up to around 90 degrees.

Just under boiling. Yeah.

So, how long it does the corn stay in here

at that temperature with the lime?

Approximately two minutes.

And this is all about creating that perfect dough that we need

to get the correct texture for our tortilla chips.

Brilliant.

Once they're cooked, the kernels are soaked and pumped into

one of 44 one-tonne soak tanks,

where the pericarp will continue to break down.

Ha-ha!

How long does our corn have to stay in one of these?

Around 15 hours we have to soak the corn for, to get the correct moisture.

What percentage moisture are you looking for?

So, in the cooking process, we're looking for around about 40% moisture.

When it gets to this stage, we're looking for around about 50%.

What happens if it goes above 50% moisture?

It becomes too mushy, and we can't make a dough out of it like that.

You won't be able make a tortilla out of it? That's correct, yes.

Do you want to take a sample with this, Gregg? Me?

Yeah. Oh, really?

Oh, right, OK, I can feel the corn.

Wahey!

Take a few kernels.

Well, they're definitely getting soft and mushy.

Oh, look, here's the skin coming off, I can see it.

Yeah.

So, that's the pericarp that's coming off, it's dissolving.

It's getting broken down really slowly.

And these are getting more liquid in them? Yeah.

So, the kernels, you'll see that they're actually increasing in size

and the moisture is increasing.

Listen, if you're going to be making a dough for your tortilla,

you need starch. Yes.

And it's that starch that's absorbing the moisture

within the actual soaking and cooking process.

Hey! OK.

Richard, you are a star. Thank you very much.

Cheers, Gregg. Thank you.

The starch in the corn helps to create the right texture

for my tortilla dough and, because we've only selected whole kernels,

none of it is being lost here, even during a dip in the tub.

Now, this little thing is actually one of the starchiest vegetables around.

And Ruth has been finding out how the unique properties of starch

have played a surprisingly important role

in ironing out our history.

While starch is vital to the production of our food,

it's also played a leading role in the story of our clothes.

I have such strong memories from childhood of fresh, crisp sheets.

And that crispness was achieved through the use of starch.

I mean, if you're my generation, you may have used something

like this to starch collars and cuffs on shirts.

But the history of laundry starch stretches back

to the Elizabethans of the 16th century.

In houses like this at Harvington Hall, servants would toil away

to process the starch for linens and clothes.

But there was one garment in particular

that they really wanted to starch - the ruff.

These elaborate collars were fashionable symbols

of wealth for men, women,

and the very uncomfortable children who wore them.

Now, as a historian, I have in fact starched a fair few ruffs myself.

It's a bit of an art form.

But I've always wanted to understand how starch acts on flimsy fabrics

to transform them into such beautiful,

stiff-as-a-board specimens.

So I've invited Professor Mark Lorch -

Head of Chemistry at the University of Hull - to explain the science.

These are amazing. I love ruffs.

I really love ruffs!

But, before we stiffen them, we need to make our starch -

which the Elizabethans did using home-grown plants and crops.

It was primarily wheat they were using.

if you didn't want to do that, there's bluebell bulbs.

There were lots available. Of course. There's plenty of starch,

thinking about it, locked up in the bulbs,

because that's the store of energy

and means that the flowers can bloom again next year.

And, then, rice. Which, believe it or not,

we were actually growing in Britain. That's amazing.

Tudor servants extracted starch by boiling and straining

these crops over an open fire for days.

To speed things up, we're using rice that has already been ground down.

Looks like a badly made gravy, doesn't it?

The starch is released into the water as a sticky scum,

a bit like when you overcook rice at home.

We can see that going all milky.

Oh, yes, that's starting to change, isn't it? Yep. Really quick.

That's the starch that's been suspended in the water.

So, there we go.

The most elaborate ruffs for the highest status Elizabethans

were made of a strip of linen up to 50 metres long.

They required a lot of stamina from the servants,

who laboured making starch for at least three days,

before they took on the ruff itself.

And the full starching process, from now on in,

we're talking about five hours. OK..!

Going to be here for a while, then.

Before applying the starch, the ruff is washed in soapy water.

As well as their size, the pure whiteness of ruffs

reflected wealth by displaying that the wearer could afford

to be super clean.

So, how exactly does this work, then?

Well, there's loads of actually really interesting chemistry involved.

It might be best if I actually draw this out for you.

Linens are made up of long, thin molecules,

all linked together by masses of weak hydrogen bonds,

and together they form quite a strong network.

But these hydrogen bonds can break apart,

and reform in the wrong place when the fabric gets washed or creased.

The way starch helps, then, is because starch is a very similar

molecule to the molecules in linen.

These can then form hydrogen bonds with your linen

and holds it all in place.

So, it's like a rigid scaffold being put on top?

Yeah, exactly. But it's all down to these hydrogen bonds.

That's so interesting! I had no idea.

The strengthening power of starch gets to work when the fabric

is heated, and to do that we need some Elizabethan laundry weapons.

What we need to now do is, to form the shape.

So, you can just pinch, push the iron in, and lift.

OK, let's have a go.

But what's happening to the chemistry of the starch?

What's going on here is, those hydrogen bonds,

we're just breaking those with the heat from the iron,

and then reforming them in the shape of the iron.

So, as the pressure of the iron heats the fabric,

the starch locks it all in place to create the stiff shape of the ruffs.

How's that? That's coming, isn't it?

Have a feel. Yeah, solid.

By the 1600s, the use of starch meant that ruffs

could grow to astonishing proportions.

In fact, they restricted the movement of their wealthy wearers

so much that servants had to perform most tasks for them.

And it's not that easy for us, either,

on our more low-key Elizabethan dinner date.

They're pretty uncomfortable, but it certainly makes you sit upright.

It's really good for posture. Yeah. Posture and etiquette.

Maybe we should toast the starch.

So, here's the starch, supporting fashion for 500 years.

Back in Coventry, my corn has been cooked and soaked for 15 hours

to soften the hard shell and pump up the kernel to 50% moisture.

So, I'm heading to the tumbler area...

..where my corn is getting in a spin with research and development

specialist Dr Depesh Pankhania.

Gregg, that's our washing tumbler.

That is like a cement mixer!

How much corn going through this thing?

So, currently, we've got 1,800kg per hour.

There's 14 jets spraying water constantly at 70 psi, roughly,

and that's washing the corn, and also helping to get rid of

that last bit of pericarp that we've got there.

One of the last steps for nixtamalization that we've got.

Can I touch it? Yeah, go for it, Gregg.

That's still rock hard. I know.

But if you compare that to what the intake corn was,

and that was about 15% moisture.

Ah-ha-ha!

Yeah, yeah, yeah, yeah, yeah. And that's really plumped up.

And it's also lost its pericarp, so it's a lot more yellow.

Right, right. OK, all right.

Its pericarp coat's come off, it's swollen up.

How much bigger is it? So, it's about 25% bigger.

Right, I'm getting the hang of this process.

I'm really enjoying this.

A yellow river of five million kernels an hour

travel six metres along a drain belt,

before dropping into a hopper.

Gregg, this is our mill.

So, the mill, I'm guessing, is crushing the corn kernels

and making them into, like, a flour, a cornflour?

No. Let me show you, first of all, Gregg.

Give us your hand.

Oh.

Oh.

That's like a... like a paste. Correct.

So, this is what we're doing. We're trying to make a dough...

Hang on a minute.

If I was going to make a dough at home,

it would be some flour and some water.

Whoa. Whoa, whoa, whoa. Right...

You've already made the dough. Correct.

Hang on a minute, I'm amazed.

I thought you had to make a dry flour. No.

What we've done now is, we've crushed this corn here

in our two mill stones.

Basically, the two stones that weigh about 25kg.

And we've crushed it into making a dough to give us

the authentic tortilla chip.

But wouldn't the ancient Mayans have originally crushed

this into a flour? No.

So, the idea is that we want to make something called masa,

and this is what we call masa.

Masa? Yeah.

So, it's Spanish for "dough".

Masa. So, in the late 1960s, this landed on the moon?

Not Nasa. Masa, with an M.

This can't be traditional, is it? Yes, it is.

Well, this is how they've been doing it for thousands of years, Gregg.

That is unbelievable.

That is just incredible.

But you have got to get the mix and the soaking and the lime solution

absolutely right, haven't you? Exactly.

And that's why it's so critical.

Otherwise, you would never get this dough. No.

You know, that's amazing.

So, this is the final step of nixtamalization.

No wonder you were so concerned about how much moisture was in it.

Exactly. You're actually going to make proper tortillas.

Exactly.

This is amazing!

Job's a good one.

It takes just 60 seconds for my freshly milled masa

to be pumped through a system of pressurised pipes

to the sheeting machine.

So, we've got the masa that's coming through the pipe

and going through what we call the fish tails.

The fish... Yeah, I can see why they're called fish tails.

The dough seems to be coming out of there quite slowly,

although it is thick. Correct.

The fish tail distributors drop an even layer of masa

across the length of two rollers.

Corn is getting pushed onto that front roller,

and underneath there you've got your cut-off,

which is just like this.

And we've got a wire that's going across, which is basically

like a cheese wire, that's taking off the chips.

Otherwise, the dough will just circle around that front roller.

The two top rollers are just to make the fat dough really, really thin?

Correct.

This then sits underneath it and cuts it into shapes? Exactly.

Then there's a wire on the front roller that catches those

triangle shapes and puts them on the conveyor belt,

otherwise, they go back in the machine again?

Correct. Whoa!

Brilliant!

This incredible process has been all about getting

the right moisture content for the dough.

If the corn is too wet, the masa would be too sticky for the machine.

And low moisture would make it difficult to cut

into perfect tortilla triangles.

Why are they called tortillas?

So, they get it from the Spanish "torta", which means cake.

Little cake? Yeah.

This machine cuts a staggering 11,700 triangles every minute,

before they speed off to the next stage of production.

Snacks like tortillas are a big hit at the cinema,

but the most popular movie treat we munch on is popcorn.

So, how did this American import become a British box office smash?

Cue Ruth.

Like Laurel and Hardy, or Thelma and Louise,

cinema and popcorn are a double act,

and it's hard to imagine one without the other.

But how did popcorn get this starring role?

To find out, I'm taking a trip to the flicks

with film historian Dr Robert James...

Hi, Ruth. Hello, Robert!

..who, like me, loves his cinema snacks.

Popcorn, please, sweet. Salty for me, please. OK.

So, where exactly does popcorn start?

Initially in America, in the Midwest,

because it's where corn is grown.

The first machines to pop corn kernels

were in Chicago in the 1890s.

It was sold by street vendors, who often pitched up outside

of cinemas and would sell it to cinemagoers

before they went in to watch a film.

At first, managers didn't want snacks inside.

But when the economic disaster of the Great Depression hit

in the 1930s, they needed a way to entice customers

to part with their cash...

..so they started to sell goodies inside the cinemas.

There's a great amount of confectionery being sold

in cinemas at that time, because they could make a lot of money.

But why is it then that popcorn becomes king?

Mainly because of the Second World War.

During the war, sugar was rationed.

Sugar must be distributed as equitably as possible

for household and industrial uses.

Suddenly, American cinemas couldn't get hold of the sweets

they'd become dependent on.

So the only thing that could make money on, really, is popcorn.

The cheap and widely accessible American corn exploded into cinemas,

and soldiered on through rationing when other snacks failed.

But in 1940s Britain, most of us had not even heard of popcorn.

So, how did it fly across the Atlantic and pop up in our cinemas?

I've come to the Imperial War Museum in Duxford...

Hello, Emily! Hello.

Nice to meet you. Nice to meet you.

..where curator Emily Charles is going to fill me in.

What an amazing bunch of planes. They are all American, yeah?

Yeah, that's right.

From 1942, after the United States had entered the Second World War,

about half a million servicemen were serving with

the United States Army Air Forces -

and that includes right here at Duxford.

And what's that got to do with popcorn?

Well, the arrival of the Americans was a huge culture shock.

They seemed very glamorous and also brought with them great luxuries,

and popcorn was one of those.

War flash. Yanks occupy London.

But, of course, it's a friendly invasion.

So, what are these, then?

These are popcorn balls.

Popcorn balls?

They're quite a popular American confectionery and the sort of thing

that American servicemen would have been sent from home.

Can I try this? Absolutely. Is that all right?

Food is really important for morale,

especially when you're serving overseas.

I like the idea, too, of it being, you know,

a home-made thing by your mum.

Now, that's really got to mean a lot, hasn't it?

Yeah, it's really special.

And with the airmen came American movies.

Most bases had a cinema.

Here at Duxford American Air Base, there was a permanent cinema.

What sort of films were they showing on air bases?

So some of the most popular films were animations.

The animations were cutting edge technology for the time.

They wanted that escapism.

You don't want to be reminded of your day job

when your day job involves putting yourself in great danger.

And movie nights weren't just for the troops.

Sometimes, the local population were invited to come and join in.

And since the American airmen were enjoying popcorn...

Exactly.

So, there was a lot of cultural exchange

and, so, sharing popcorn was another aspect to that relationship.

For three years, American airmen shared their favourite treat

with us Brits - and our love of cinema, and popcorn, stuck.

Who'd have thought that popcorn could have such a place in history?

To save American cinemas in the Great Depression,

then to cross the Atlantic and comfort the troops during World War II -

and all from a puffy little bit of corn.

At the tortilla factory,

I'm 17 hours and two minutes into production.

My corn has been made into masa and cut into 14 million triangles.

Hot.

Now it's time for a change of temperature.

Ah-ha-ha!

Oh, that is hot.

That is red hot.

So, Gregg, this is our crusting oven. Crusting?

So, it's basically a triple pass oven.

So, the chips are coming off those conveyors, going through this oven,

and they're going past three times at three different temperatures.

What we've got is the top oven, which is your infrared,

at about 400 degrees.

And what that's doing is trying to really get a hard crust

on top of your chip.

And then you've got the second pass of the oven,

which is about 370 degrees.

The second oven creates the crust on the bottom of the chip.

And the third is set to 250 degrees.

That's equivalent to your conventional oven at home,

and that's basically trying to evenly distribute that moisture

across that tortilla chip.

The moisture inside will help to create those blisters,

which is basically a part of our authentic tortilla chip.

How long is each chip staying in there?

17 seconds.

No, that can't be right.

It is. That can't be right!

That goes through three separate ovens in 17 seconds?

How many individual chips are coming out of here?

So, it's about 10,000 chips every minute.

Extraordinary.

Despite the heat of three ovens,

the moisture content has only been reduced by 10%.

So, if you take a chip...

..what you'll feel is the hard crust on the outside.

Well, it's crusty, but it's really bendy. Exactly.

If you rub it between your two fingers,

you've still got some moisture,

and that's the 40% that we still want to keep within that chip.

So, onward and upwards.

I'm following my baked but bendy chips as they trundle along

12 metres of conveyors...

..to quality manager Jyoti Saita,

who's putting the crisp into my tortillas.

Hello.

Hello, Gregg.

This is now the final stage of cooking.

The first step as soon as the chips enter the fryer

is what we call a free fry zone.

The chips are let loose to be fried.

The oil - a blend of corn, sunflower and rapeseed oils -

is heated to 180 degrees,

and the chips free fry for just five seconds.

The next step is a drum.

We call it clump buster.

The drum basically keeps the chips separated

so they don't stick together in the fryer.

The third step in the fryer is four large paddles

which flip the chips in and out of the oil.

Inside the fryer, the chips flow with the oil along the pan,

and are turned by the "clump busting" drum and rotating paddles.

As they cook, the trapped moisture turns to steam,

which raises the surface of the dough.

The steam is what actually forms the blisters, or the bubbles.

The blisters, or the bubbles, are really, really important

to form the texture, and that's what gives us the crunchy texture.

You must... Right, this is why you want this moisture, right?

Absolutely.

You want the steam to come up and bubble up the surface.

Yeah.

No wonder... Every step of the way, everything is moisture,

moisture, moisture - and it's making you your bubbly top.

That's right.

Is all the moisture now out of this chip?

We try and maintain now to around 1% of moisture.

So, it's never completely gone? That's right.

How long does all of this take?

Just 60 seconds, Gregg.

60? 60.

Three stages in one minute?

About 60 seconds, absolutely.

Am I allowed to taste these? Absolutely.

We can take some samples in here...

Wow!

..and you can try them now.

Well, I just wanted to see the blistering,

and you can clearly see it.

It gives it, like, a surface, like the surface of the moon.

You can see the little raised surfaces.

We keep the blisters less than seven to eight.

If it's too many blisters, it absorbs too much oil

and it loses the crunch, and we don't want that.

Well, they're crispy. May I?

That's what creates the crunch.

They're lovely and crunchy, they've got a mild corn taste.

But they need flavour.

Even if it's only salt, they need flavour. Absolutely.

That's our next step, Gregg. Oh, is it?

I'll show you how we flavour our chips.

Yeah, come on, then. Put that down. Let's go.

I'm taking another one, but just for professional interest.

And while I munch on a perfectly crispy chip,

thousands of others trundle along to the next destination - seasoning.

Of course, tortilla chips come in a huge variety of flavours.

Mine will be chilli.

And this spicy little plant has become very popular

in all sorts of dishes here in the UK.

But how much heat can Cherry handle?

As a nation, we're crazy for chillies -

eating a whopping 230 million of them every year.

Most are grown in Morocco, Spain, Egypt and Kenya.

But if you thought that chillies only grow in hot countries,

think again!

Because I'm in Bedfordshire.

This is the UK's largest chilli farm,

where they grow up to one million fresh chillies a week.

Salvatore Genovese is in charge of this ten-acre indoor chilli crop.

Let's go for a ride, come on.

What an amazing place!

This is a really impressive greenhouse, it looks very high-tech.

Why do you have all this amazing kit?

There's lots of reasons, but I think one of the key ones is

we try to keep the heat, the strength of the chilli, consistent.

So, if it gets really hot in here, the plant gets really,

really frustrated and angry.

Too much variation in temperature makes the plant stressed,

which over-intensifies the heat of the chillies as they grow.

To regulate it, Salvatore uses huge electronic thermal screens

to block intense sun in the summer

and seal warmth inside during the winter.

So, you can decide what the weather's like in here

at the touch of a button?

Really, if I get it right, I can double the yield.

But, then again, if I get it wrong,

I can actually kill the crop at the same time.

Once ripe, the chillies are all picked by hand.

Is there a trick to picking a chilli?

There's a natural little break point,

and it just snaps off like that.

It's a twist? It's more of a snap.

Is that a first one? Well done.

When's the best time to pick a chilli?

We start harvesting around April and we'll go through to November.

How often do you harvest?

I really want to pick the same plant at least once a week, twice a week.

Once a week? Although, sometimes, there's just billions.

It's just red everywhere, and you just can't get around fast enough.

The plants are fed nutrients via a drip,

guaranteeing a whopping crop of up to 25 tonnes every week.

Salvatore grows more than 20 varieties of chilli,

all with different levels of heat.

So, he's going to give me a lesson on how to rank them -

according to a system called the Scoville scale,

which measures the pungency of peppers,

starting at zero for a mild salad pepper.

What do we have here?

A selection of British chillies.

The most famous classic is your jalapeno.

On the Scoville scale, how hot is a jalapeno?

That's one of the mildest ones, that's around 5,000.

It sounds like a lot, but 5,000 Scoville heat units is pretty mild.

The scale climbs a lot higher than that.

Go a little bit hotter - serenade.

Great chilli, 20,000 on the Scoville scale.

Is it getting a bit more dramatic around here? Well...

The habanero scotch bonnet.

Extremely incredible flavour.

The scorching Scotch bonnet is a smoking hot 350,000

on the Scoville scale.

And we're not done yet.

What's under there?

We have officially the hottest chilli in the world.

Whoa.

The Carolina Reaper.

It's small, but very angry looking.

So, on the Scoville scale, how hot is the Carolina Reaper?

Around 1.8 million.

Very dangerous.

The Reaper can be dipped in curries for a super-hot chilli kick.

And, with our growing taste for heat,

they're now sold in supermarkets.

You've got 400 jalapenos here.

This little thing is equal to all of those.

Oh, my goodness!

That tiny little chilli is the equivalent to a crate of jalapenos?

Mm-hm.

Why are chillies spicy?

It's all to do with the capsaicin that's inside the chilli.

When you eat a chilli, your mouth starts to burn.

But it's not really burning.

Cos that capsaicin is fooling your brain to think

your mouth is on fire, where it really isn't.

I'll show you. So, if you grab a chilli...

Contrary to popular belief, it's not the seeds,

but the white pithy membrane which packs the heat,

triggering the same nerve receptors in our mouths

that tell us when food is hot in temperature.

So, my brain thinks this is really hot, as though

I was drinking a very hot cup of tea? Yeah.

So, what will my receptors make of the Carolina Reaper?

OK, I've come all the way to Bedfordshire,

I should probably try it.

It's quite a nice flavour. Mm-hm.

Don't try this at home.

Uh...! OK, I've got it.

Uh!

CHERRY COUGHS

It's hot... Milk?

Oh! Guzzle that.

Put hairs on my chest...!

You would not want to eat one of those without knowing about it, would you?

And that is why we have the Scoville scale.

If you can't stand the heat,

I really would avoid the Carolina Reaper.

But if you think a bit of spice is nice, it's thanks to farms

like this that, when you bite into one of these,

you don't get a nasty surprise.

Back at the factory - and 17 hours and four minutes into production -

my tortillas have left the fryer and joined a superhighway of chips,

heading to the flavour tumbler, ready to be doused

in the factory's most popular seasoning, Chilli Heatwave.

This is our seasoning hopper.

That aroma is extraordinary.

It's almost like a sweet pickle and lots of pepper.

What is it?

It contains paprika extract, garlic, onion and some salt.

How much of this do you go through?

So, for chilli seasoning, we use about three tonnes per day.

Three tonnes a day? Three tonnes a day.

Can I taste this? Cos the aroma is really powerful.

Sure, Gregg. There's a sample right behind you.

If you open, you can have a try.

What does that taste like?

Slightly sweet...

Slightly sweet. Very, very salty.

Sweet like a pepper...

..and a creeping heat of chilli.

That's Chilli Heatwave.

Around 90 kilos of chilli seasoning is loaded into

a 2.5m spinning drum every hour.

And my chips, still hot from the fryer,

are dropped in 100 at a time.

How long are the chips in the drum?

Just 50 seconds, Gregg.

It's all so, so quick.

So, how many are we watching going past here?

About 1,000 kilos an hour.

And that will make 6,500 bags of Chilli Heatwave.

Every one of my chips is coated in 0.2 grams of spice

and, together, they travel along a pocketed conveyor

to the largest room in the factory - packing...

..where I'm meeting Victoria Hodgson.

Victoria, hello. Hi, Gregg.

These look like a lot of fun.

Yeah, these are our multihead weigh hoppers.

Multihead weigh hoppers?

Yeah. Right.

Yeah, got it, I got it. Go on.

So, the chips fall onto the central scale, and they shuffle across

into the 14 weigh hoppers.

Each hopper weighs a handful of chips, and when the bag below

calls to be filled, a computer, in a millisecond, calculates how many

grams are in each hopper, gets the best four hoppers

and puts it into the bag below.

How fast is this machine filling bags?

70 bags a minute.

And how many of these machines are running here?

In the whole factory, we have 100.

Doing roughly 70 bags a minute? On average.

All day? All day, every day.

Wow!

That's crazy!

From the weighing hoppers, the chips fall through a chute,

filling a bag with 150g of tortillas.

A tiny blast of nitrogen is added into the bag,

before it's pulled through two hot jaws to create a seal

at the top and bottom.

Why nitrogen?

To keep them fresher and to stop them going stale.

It's harmless, is it? It must be. Absolutely harmless.

And if you didn't put them in there, what would happen?

It would lose its smell, it would lose its taste,

and it wouldn't be as fresh as when it came out of the seasoning drum.

Cos it's more like a pillow - I'm guessing here -

does that help it...? Absolutely.

It cushions the bag and keeps all those triangles intact.

12 packets of my spicy tortillas fill each box,

which then salsa along a network of roller conveyors,

bound for dispatch.

These days, most factories are trying to find ways

to make their packaging more environmentally friendly.

Cherry's tracked down a British invention

that could be a game changer.

Crisps and snacks take just minutes to eat -

but their packets can stick around for decades.

Lots of plastic waste ends up in our oceans,

and old crisp packets like these can sometimes be washed up

onto our beautiful British beaches.

Incredibly, some of them are over 50 years old,

and they've hardly degraded at all.

In the UK, we chomp through six billion packets a year -

but only a fraction of these are recycled.

And that's largely because there's a lot more to your average crisp bag

than meets the eye.

A crisp packet is actually made from four very distinct layers.

Meet packaging scientist Mike Swain.

I've built a gigantic model for you to have a look at.

This is the layers of the packaging explained in big detail.

A packet's inner layer is transparent food-safe plastic.

Layer two is aluminium, just a few atoms thick,

that stops moisture and oxygen from the air getting into the bag.

So, without this, what would happen to the crisps?

The crisps would go stale and they'd also lose their crispness.

You'd get a bag of soggys! You certainly would.

Layer three is the print for branding

and glue to hold the layers together.

And the outside is also transparent plastic

to make the bags strong.

How do they all work when it comes to recycling?

Unfortunately, it's very difficult and costly to separate these layers

once they've been put together.

In fact, it's cheaper to make a new packet.

But hope is on the horizon.

So. I'm going in search of the UK's first plastic-free crisp packet.

And the key to this British innovation is a special film.

So, I've come to Carlisle to meet Andy Sweetman

to find out how it's made.

Why have we stopped at a big pile of cardboard?

Well, Cherry, this is actually wood pulp.

So, that's come from trees, and that's the key raw material

for what we're going to make into film.

You must perform some kind of magic to turn this into a crisp packet.

It is really quite magic.

OK, I need to see it to believe it, Andy.

Let's go.

First, this sustainable wood pulp, from South America,

is sent to the pulping room...

It's absolutely massive!

..where the bales are lined up,

ready for me to get the enormous mulching machine started.

Do I have to press it at the same time?

Roughly. OK.

Three, two, one!

Go! Go, wood pulp!

So, what we do is take those sheets

and break them down progressively into cellulose.

This wood pulp is full of cellulose, a strong fibre in the cell walls

of plants that gives them their structure,

and which is also used to make paper.

Once they're loaded, the bales are shredded in the pulper

with water to start the fragmentation of the cellulose.

It looks like a giant blender.

And that's essentially what it is.

We've added in an extra ingredient, caustic soda,

and it's reacting with the wood pulp to open up the chains of cellulose.

And that's critical, because we need to regenerate them into a different form.

In there, it basically looks like porridge.

Oh, look at this!

We're trying to move from wood pulp to transparent film.

We've got to break it down fully so that we can then regenerate it,

and it will turn transparent.

After 24 hours, the raw cellulose fibre has been broken down enough

to become a gloopy liquid called viscose.

So, that's our cellulose in liquid form.

So, it goes from porridge...

So, you add chemicals to the porridge... Yep.

..to turn it into marmalade? Yep.

It comes through the pipe work into this part of the machine.

And that's like two lips very, very close together,

and as it goes through the lips and into the bath,

it transforms into film.

What is in the bath?

So, this is a bath of dilute acid,

and that transforms it into the film.

It's essentially transformed the molecules of cellulose

and lined them up. So, although, it's chemically identical

to paper, it turns transparent.

In an incredible reversal of the first chemical reaction

that turned the fibrous cellulose into liquid,

the acid bath regenerates it to pure cellulose -

not back to fibre, but in the form of a clear film.

Wahey!

Just like magic, it's turned to film!

Last thing it needs is a little bit of a wash,

so that we get it crystal clear.

It's beautiful.

So, it's a food-safe, solid film?

That's right.

It looks like plastic, but it is not plastic.

That's some seriously clever chemistry.

This biodegradable cellulose film is sent off-site

to be coated with a microscopically thin layer of aluminium...

..and printed with the product details...

..before being loaded up with crisps.

It looks exactly like plastic.

But, really, it's a transparent paper.

It's made from cellulose, not plastic.

Is this a UK first?

Yes, absolutely. This is the first certified compostable,

certified plastic-free crisp bag.

So, for the first time in the UK, you can put a crisp packet

like this in your compost to biodegrade, in around 30 weeks,

which is great news for those of us that love snacks

and great news for the planet.

After 17 hours and eight minutes,

my tortilla chips have been seasoned,

sealed inside bags, and boxed,

before heading to this crazy place...

..a room of robots juggling boxes of different chip varieties,

including my Chilli Heatwave.

Wow!

Wow. Seriously, I mean, I've seen stuff like this before,

but this is very, very impressive.

What's happening and how fast are they doing it?

So, the computer scans the barcode on each box and sends it

to the right robot.

So, the robot will pick up 15 boxes a minute

and put them on the correct pallet.

So, an average pallet has 60 boxes.

Wow. So, it will take four minutes to complete the pallet.

Wow! And then it goes off down there to be wrapped up, does it?

To be wrapped, labelled and dispatched.

And how many pallets are you doing in a day?

So, between the two, that's 768 pallets.

768 pallets of tort...!

43,200 boxes.

That...

That is amazing.

Well, I'm glad Victoria has done her homework.

The pallets are wrapped, and my tortilla chips

are finally ready to hit the road.

Dispatch, right?

Welcome to dispatch.

And it's a massive dispatch, as well!

Are these mine? They're yours.

Wahey!

Go on, sir.

Oh, look, I've seen these every single step of the way.

Shall we send him off? Yeah. Can I do it? You do it.

Go on, boss! Send her away.

I tell you what, it's been quite experience, quite a journey.

This factory sends 50 truckloads of tortilla chips

all over the UK every day.

Most are munched in London, followed by central England.

I have to say, being in this factory,

I have never seen so much corn in my life -

almost 200 tonnes of the stuff delivered here every day.

I've almost got yellow spots in front of my eyes.

But what really amazes me is, even at a big, massive modern factory

like this, the process they use to make the dough for these crunchy

little fellas is ancient, it's thousands of years old!

I am never going to look at a tortilla chip in the same way again.