Original subtitles

Thank you very much.

Whether it's in a cone... Mm!

In a tub...

..or even with your favourite pudding,

we can't get enough of ice cream,

eating almost 444 million litres every year!

So I've come to find out how it's made at a family-run factory

that produces over 11 million litres of dairy ice cream every year!

I'm Gregg Wallace...

I am so happy! Oh, brilliant!

..and I'm following ice cream, from cows...

Whoa, what do you want?

..to volcanic cooking...

Dangerous, that's red-hot.

You've got to be careful.

..and finally, freezing.

Wow! How cold is it in here?!

It's as cold as the Arctic in winter.

I'm Cherry Healey...

..and I've come to this sweltering greenhouse

to find out why this lolly just won't melt.

And I'm discovering why ice-cold treats

can quickly turn from pleasure to pain.

You are an animal.

Why haven't you got brain freeze? WHISTLE BLOWS

And historian Ruth Goodman...

Whoa, my first ride in an ice cream van.

..is revving up to explore what drives our love of ice cream vans.

Ah! Whoa, whoa, whoa!

They make 50,000 tubs of dairy ice cream a day here,

and I'm going to reveal just how they do it.

Welcome to Inside the Factory.

I've come to the heart of rural Aberdeenshire,

to the Mackie's ice cream factory.

This family business churns out more than 49 tonnes

of dairy ice cream every day.

And I'm going to learn how they make one of their best-sellers -

the one-litre tub of honeycomb ice cream.

So to get the scoop on how it all begins,

I'm heading to the factory's very own milking parlour,

where this lot of lovely ladies

are producing the fresh milk I need for my ice cream.

HE CHUCKLES

There's been a dairy farm on site since the 1920s.

In charge today is farm manager, Dave Smurthwaite.

Dave. Gregg. How are you?

Do you know, I really didn't expect to see this

at the edge of a factory. Yeah, it's great, isn't it?

How many cows have you got here?

About 300.

In this 9,000 square metre barn,

Dave runs a state-of-the-art set-up.

So tell me about the operation.

Well, it's a fully automated system.

The cows voluntarily go and get milked up to five times a day.

Hang on, hang on. Voluntarily? Voluntarily, yes.

The cows just go, wander up, when they feel like getting milked,

will go and get milked. It's an amazing system.

Right, this one's going in. Tell me what's happening.

You see on this side of its neck, there's a responder,

that responder reads the reader up there.

You'll see the red light on the cow. Oh, yeah, yeah! That's a laser.

And it's picking up the coordinates of the cow's teats now.

Those flashing lights are like a milk cow disco.

DISCO MUSIC PLAYS

There are five of these robots dotted through the barn.

Each uses infrared light to attach itself to the cows teats...

It's properly lining it up. Wow!

..and it adjusts automatically if the cow MOOVES during milking.

Isn't that extraordinary? Amazing, technology, what it does.

Go ahead. Bull's-eye.

The cows have been trained with tasty barley treats

as an incentive.

She's thinking, "This is great." She's getting some sweeties there.

So when their udders feel full, they know what to do.

So as soon as that cow goes in there,

the computer picks up the chip in her collar...

Yes. ..and knows who it is. Yes.

Effectively, like your fitness watch,

it's recording how many steps it's doing,

how many minutes it's spent eating,

it's telling us how much milk it's projected to give

every time it goes to the robot.

It takes around seven minutes,

and each cow can be milked up to five times a day.

Oh, the teats are falling off.

That's done, right?

And off she goes.

With each cow producing around 39 litres,

the herd of Holsteins has a total yield of some 11,000 litres

every day,

all of which goes to the ice cream factory.

So how many cows are you going to need to milk

to give me my proper batch of ice cream?

Well, we would need to milk 40 cows to get your batch made.

That's easy for you, isn't it? No problem.

We'll have that in half an hour.

Whoa! What do you want?

Do I look like a milking robot?!

For my 5,000-litre batch,

I need 1,500 litres of milk.

And as the robots whir into action,

the countdown from cows to ice cream begins.

Have you always been this tall? Cos you make me look really little.

Yeah, well, it's all the ice cream I've eaten, you know?

We all love to tuck into an ice cream on a hot day,

but eating it too quickly can give you a terrible headache.

Well, Cherry may have an answer to this perplexing problem.

There's one kind of ache that even an ice hockey helmet

can't protect you against.

Brain freeze.

Every time you take a sip of an ice-cold treat, you run the risk.

Very quickly, pleasure turns to pain.

WHISTLE BLOWS

Before the coronavirus pandemic, I visited the University of Hull

to meet headache guru Dr Fayyaz Ahmed.

Ever since I was small, I've wondered what is going

on with brain freeze, why do we get it?

It's a protective, normal mechanism.

So when the ice cream comes, it touches the top of the mouth

and the back of the throat, and that's the sensitive areas.

Because of the rush of the blood,

the pain receptors, which are in the blood vessels,

perceive it as a pain. Yes.

They communicate with a nerve called trigeminal nerve.

Here you can see the trigeminal nerve, which is shown in white,

goes to your forehead... Yeah. ..and the eyes.

So therefore, you feel the pain mainly in your forehead. Right!

So the actual sensation is happening here in the mouth,

but because it goes up the trigeminal nerve,

it feels like it's happening in your head, but it's not.

There's nothing actually going on in your brain.

Nothing. The brain is just saying, "Stop it."

Stop eating the ice cream.

This is like a panic button.

But once the brain's panic button is pressed,

is there a way to stop the horrible headache in its tracks?

Break time!

Who wants a slushie?!

Ooh!

To find out, we've enlisted the help of a local ice hockey team

who have volunteered to scoff some slushies in the name of science.

I'm afraid you today are our brain-freeze guinea pigs.

Do you mind having a bit of brain freeze?

For you. Thank you so much.

In the name of science!

Dr Ahmed has suggested three techniques

to get rid of brain freeze.

Each one warms the blood vessels in the mouth.

But which is most effective?

One for you...

We've split the players into three groups,

and we'll time which technique is the fastest.

Method number one...

When you get the brain freeze, you put your fingers up,

and then put your tongue under, touching your roof of the mouth,

but keeping your mouth closed.

Three, two, one. Drink those slushies!

Don't forget to put your finger up when you get brain freeze.

You got it. We've got one. One down, one down.

She's got it. She's got it! That's another one.

Are you putting your tongue at the roof of your mouth?

Yes, you are too. Good.

You are an animal.

Why haven't you got brain freeze? Yours is gone? Gone.

Can you please describe what just happened?

It went straight away. It went. It cleared.

Ahmed, what is method number two?

As soon as you feel the brain freeze coming,

close your nose or your mouth, like that,

and breathe and re-breathe into it.

Here you go. Little pot of pain.

Three, two, one.

It's brain freeze o' clock!

Oh, yeah.

It's gone.

I think it was almost quicker than the tongue on the palate.

For the last test,

our players will drink warm water when the pain strikes.

Anyone?

Yeah, there it is.

Still got brain freeze?

Is it gone? It's gone.

Tests complete, and the timings are in.

Thank you very much, you can have that.

First, we tried the tongue on the roof of your mouth technique.

On an average, it took about 13 seconds to end the brain freeze.

Next was blowing into your hands.

3.5 seconds.

And finally, how was warm water as a cure?

About ten seconds.

So putting your hands over your mouth and blowing

was a clear winner by about six-and-a-half seconds.

And I can hypothesise that because when you're re-breathing,

it's your own warm air going back quickly.

That's why you get it a bit more quicker.

So your blood vessels get a nice, warm breathe

and stop contracting. Central heating.

THEY CHUCKLE

We've given you knowledge for life.

Now get back on the ice!

There we have it, the world finally has a cure for brain freeze!

So when you feel the pain setting in,

cup your hands to your mouth and blow hot air,

warming up your soft palate,

and hey presto.

I think I might have had enough slushie for one day.

COW MOOS

Back in Aberdeenshire,

I'm 30 minutes into production of my ice cream.

The cows have been robo-milked and 1,500 litres are pumped

from the shed into the mixing area...

..where the milk is combined with 500 litres of cream.

And I'm meeting Kirsten Mackie, whose family runs the business.

You must be Kirsten. Kirsten, hello!

Oh, hey, Gregg! Can I come up? Nice to meet you.

Yeah, come on up.

Today, we're going to make honeycomb.

Oh! Yeah, that is our second best seller.

I am so happy!

Oh, brilliant! I am so happy.

Well, I'm delighted!

But before we get to the honeycomb, we need the ice cream,

so it's time to start adding ingredients.

Ah-haha!

This is the skimmed milk powder going in.

What happens if we didn't put it in?

If we didn't put it in, your ice cream is more prone

to go rough texture, sandy, gritty, icy.

And we don't want that.

Next, 300 kilos of sugar from British sugar beet

arrives by pipe from a silo outside.

Kind of want to lick it.

Not allowed, are we? None of that in the factory.

You can't dip your finger...? You can taste it later, OK?

This is torture for someone with a sweet tooth like me.

What are you doing? This is the emulsifying stabiliser.

Would you like to put it in? Yeah.

The emulsifiers find the fat from the cream

and the water from the milk.

Sure, things that would normally sit one on top of the other,

you have to blend, emulsify. Yep.

We have to make it all come together.

If we didn't, it would separate out.

I gotcha!

You'll see a lot of the other things that we do to the ice cream

make it really, really smooth and rich and creamy.

Smooth and rich, that's what I've always dreamed of being.

Let's go.

SHE LAUGHS

Moving smoothly along to the other side of the vessel,

we add two more important ingredients.

First, glycerine, which makes up 1% of the mix.

You see that yellow pump there?

If you just twist that...

Isn't glycerine sugar?

Glycerine is actually derived from rapeseed,

and it's not as sweet as sugar.

What do you use it for?

Glycerine freezes at -36,

and most people's domestic freezers are, what, -18, -20?

So it won't be frozen, and it'll just help it

with that little bit of scoop-ability.

And finally, five kilos of whole egg.

It's a very small amount of egg that we add to the whole batch.

Yeah, isn't it? However, it does add to the taste.

In there? Yes, please, pop it in there.

Kirsten and the team make around ten batches of ice cream a day,

a tantalising 50,000 litres.

So here we're heating it up to a very special temperature.

What temperature?

Well, that's a secret, but it's really special

because that's where the Maillard reaction starts.

I've heard of this. What's a Maillard reaction?

Maillard reaction is when the proteins from the milk

reacts with the sugars,

and it gives this really subtle caramelised note.

It's a bit like when you're toasting marshmallows, you know,

you get that lovely caramelised extra.

And that's called the Maillard reaction?

It's this reaction between amino acids and sugars

that gives cooked food, whether it's a marshmallow or a roast potato,

it's distinct flavour and aroma.

You're clever.

Thank you.

I'll put the jug down.

It's a complex business, this ice cream making.

After 20 minutes, the mixture is pasteurised,

where it's heated to around 80 degrees

to kill off any harmful bacteria.

And then it's pumped to this machine called a homogenizer.

Breaking down the fat globules into millions

of tiny little, small fat globules.

Do you think you might be able to do that to my beer belly?

Why do they need to be tiny?

This is one that we just did yesterday,

and we didn't homogenise it.

You can see it's begun to separate out.

Oh, yeah.

In the olden days, when you got your milk bottles,

do you remember how the cream would rise to the top?

So that's what's happening here.

I get it. You need your fat broken up and spread through your mix.

Absolutely.

With my mix thoroughly blended,

it's pumped to the ageing tanks,

where it's held in a 10,000-litre vessel,

the equivalent of 125 delicious bathfuls of liquid ice cream.

So this is where we age the ice cream.

Hang on a minute. We age cheese, we age wine,

you don't age ice cream, do you?

Ageing is very, very important for ice cream.

It's probably one of the most important things for ice cream.

And if you didn't age it?

Basically your ice cream mix would separate out.

The mix is aged for a minimum of four hours

and kept at a cool five degrees Celsius,

the perfect temperature for the emulsifiers to get working.

So that is just chilling out and coming together in a huge amount?

Absolutely. Yeah, it's chilling out.

It may be chilling out,

but I'm excited to have my first taste.

You can taste, like, the fresh milk.

Yeah. And actually, it's really creamy.

There's a toasty, sweet finish on that, not unlike vanilla.

Yeah, that will be the Maillard reaction.

How long are you going to keep my mix in there, then?

Your mix is going to be in there for a minimum of four hours.

Come on, then, we'll go and put our feet up, shall we?

Here in the UK, we love ice cream in a cone,

so it's not surprising that we have a soft spot

for the funny little vans that sell them.

Ruth is in search of their story.

YANKEE DOODLE PLAYS

Oh, listen to that sound!

There is only one thing that noise can mean - ice cream!

Fantastic!

But what has driven our long love affair

with the mobile ice cream seller?

I'm hoping that Ed Whitby...

Ed! Good morning. How are you? Hello!

..can give me the scoop.

Oh, wow!

What a blast from the past.

Lots and lots of memories.

Ed's family has been manufacturing and collecting ice cream vans

for three generations.

Their earliest models date back to the Victorian era.

There's everything from the early 1900s through to... Oh!

..near enough the modern day.

Starts off with, like, the penny licks.

Penny licks were ice cream sold from carts in reusable glasses,

but it was with the invention of the edible cone in the 1920s

that our taste for mobile ice cream really took off.

So when does it start to become what we know of as the ice cream van?

It wasn't really until post Second World War,

where we'd move to things such as the Morris vehicles,

and this is a great-looking van, typical of the 1950s.

The vans were evolving, and so was the ice cream.

STAR SPANGLED BANNER PLAYS

In America, aerated soft serve ice cream was highly desired.

Air was pumped into the mix by heavy-duty generators.

But they were too bulky to fit into the smaller British vans.

So a van like this Bedford CA of the '60s, very popular,

lots of them made,

but nowhere near the space to accommodate the generator.

We're trying to take this huge, great American technology

and then sort of jam it into much smaller British vans?

Yes. Time for a new system.

It was Ed's grandfather who came up with a solution.

He realised he could get power to the soft serve machine

direct from the engine.

He called it a direct drive system.

Power from the engine is transferred across, very simply, through and up.

You've got your van, you drive up,

you flick a switch. Yep.

And then your engine, instead of making you move,

now it's busily working all of this.

Through the simple pressing of a button.

You know, I mean, it's not a tiny thing, but nonetheless,

in comparison to a generator, it's pretty small and light, isn't it?

It's almost too simple.

Throughout the 1960s, the soft serve vans took British roads by storm.

And Ed's grandfather's legacy lives on.

His system is still fitted on all new vehicles leaving the factory

to this day,

and I'm taking one for a test drive.

Whoa!

My first ride in an ice cream van.

Showing me the ropes is Antonio Coronato,

who began working on the vans 35 years ago.

And he is letting me try the direct drive system for myself.

Cone in your left hand. Left hand.

And what we're trying to do, obviously, is

build the circles up with a little bit of a peak

to make it a nice presentation.

What customer wouldn't be happy with that? Exactly. That is gorgeous.

Right. So we're going to get you to do one now.

This is not going to be gorgeous.

Oh... Oh! Whoa, whoa, whoa!

Shall we start that one again, Ruth?

Well, that didn't go quite so well.

This is like an accelerator on a car.

So the further down it comes, the faster... OK, the faster it comes.

Don't let the ice cream flow control you.

My throttle control is...improving?

There you go. Better.

But am I ready to serve a real customer?

Ah! Oh, that's fabulous. It's, uh, large.

Very generous! That was great. Thank you so much.

I think my portions could bankrupt the business.

Really sorry. That's all right. Thank you.

SHE LAUGHS Thank you very much.

It's amazing to think that in their heyday,

there were thousands of these vans roaming our streets,

and still today, it brings out the big kid in all of us.

Back on the factory floor,

I'm five hours and 20 minutes into production.

The creamy mix has aged...

Yeah, I know the feeling!

..and it's pumped to the freezing area.

So this is our freezing machine,

this is where we freeze the ice cream mix.

That's proper ice.

I thought you just decorated it to make it look icy.

That is very cold.

The mix is sent into one of six freezing machines.

Got a refrigerant gas in here,

it's ammonia, it's about -20.

Why do you use ammonia to cool the ice cream?

It's a very, very green refrigerant gas.

There's no emissions whatsoever.

The ice cream mix comes in at +5

and it comes out at -5.

So is that as cold as it gets?

No, it can get much colder, but at -5 degrees,

basically 50% is still free water, 50% is frozen.

But if we get it even colder,

it would be too thick, too viscous,

and you wouldn't be able to flow it around the pipes,

and you wouldn't be able to get it into the tubs.

You don't freeze it until its final amount

cos you wouldn't be able to get it through the pipes of your machines?

Exactly. That's brilliant!

Everything is so practical. I love stuff like that.

It is, well... This might sound basic to you,

I've never been in an ice cream factory.

It takes just 60 minutes to turn my liquid mix

into a 50% frozen ice cream mix.

It's so important to freeze it down as quickly as possible.

The quicker you freeze it down, the better quality it's going to make.

This is the only part in the process where we produce ice crystals,

so we want millions of tiny, tiny ones,

and that's really important for later on in the process.

Why do you want little tiny ones?

If they're tiny, you will not detect them in the mouth,

and it'll just be like this lovely, really smooth ice cream.

Inside this ingenious machine, set to -20 degrees,

my ice cream cools rapidly as it's churned against the walls,

forming millions of tiny ice crystals.

The motion of the stainless steel blades also adds air,

creating a light and creamy foam.

So much of what you do is about maintaining texture.

Texture is so important in ice cream.

The other really important thing here is the fact that

we're adding in a certain amount of air into the ice cream.

Pump up the volume

When it comes to texture,

the most surprising ingredient in my ice cream

is actually all around us.

It's air.

So Kirsten is taking me to the research and development kitchen

to show me how much we need to make the perfect ice cream.

It's vitally important to put some air into ice cream.

Here's a sample that we made up earlier.

This one has got no air in it.

Crikey!

This is like a block of ice.

Not the texture you're after, is it, in ice cream?

No, we want it as smooth as possible.

There's no structure to ice cream there whatsoever,

there's nothing.

The next batch has 160% air.

That's too light. And it's going to disappear in your mouth,

and you're not going to get the full taste of the ice cream.

The final tub has one part ice cream to one part air, known as 100% air.

See how that compares to the solid block.

Oh, wow, that's the stuff.

That is light and not just creamy, but fluffy.

I bet if you ask people what ingredients

are important to ice cream, I bet air wouldn't come up.

If we went, "Our survey said..." HE IMITATES BUZZER

The air has bonded with the all-important fat globules,

and the end result is a tasty one.

So I'm learning, without air, you won't get proper ice cream,

you'll get a solid lump. Exactly.

It's interesting, when you learn subjects you're interested in,

how much better at it you are.

You're a good teacher.

Thank you. Thank you very much, indeed.

And I'm definitely interested in ice cream!

Do you have a meltdown every time an ice cream or a lolly

drips down the front of your T-shirt?

Well, you can chill out because Cherry has the answer.

Summer in my house means more washing,

and often the culprit is the dreaded drippy ice lolly.

But what if you could make a lolly that doesn't drip?

Cutting-edge food designers

Bompas & Parr think they've done just that.

So I'm meeting Sam Bompas at their South London studio.

Hi, Sam, lovely to meet you. Hello, so good to meet you.

Their new secret ice lolly formula

was inspired by an eccentric British inventor in World War II.

What is it? This is the Pykrete Project.

What on earth is Pykrete?

So, in 1943, British shipping is being hammered by the U-boats

who are torpedoing it.

So Jeffrey Pike realised that if he mixed ice and sawdust

at the right ratios, he could make an ice that took

way, way longer to melt, and if you've got enough of it,

you can make aircraft carriers out of it.

With steel in short supply,

the extraordinary idea of building aircraft carriers out of wood pulp

and ice was seriously considered by the military.

It was dropped after events turned in the Allies' favour,

but the concept remained.

What you're doing is you're stopping the rate at which the ice melts

through all that natural fibre inside.

So when you heard that, did a light bulb go off,

did you think, "Hang on, ice that takes longer to melt"?

So we thought, well, what if you weren't doing sawdust?

No-one wants sawdust in their ice.

That's not what I want, honestly, on a hot day.

But we found natural fruit fibres, and different fibres,

put them into the ice lolly,

and we could make the world's first non-melting ice lolly.

To test the theory for myself,

I'm working with development chef Danny Cheatham.

Hi, nice to meet you. I'm very excited.

No-one's ever made a non-melting ice lolly.

It's like the unicorn of desserts.

Where do we begin?

For the lolly mixture, we start with an everyday ingredient.

This is off-the-shelf, only from the supermarket,

concentrated apple juice.

Then natural fruit colouring is added,

and the juice is heated to 60 degrees.

That's a lovely, fresh green apple colour.

Exactly.

Next are the special ingredients to stop our lollies melting.

Can you tell me what is in this magical substance?

It's mostly products that are made from vegetables and fruit.

Dehydrated plant fibres, called konjac and gellan gum,

are added in powder form.

What is gellan gum?

It's from a lily pad.

What?! That's amazing. Yeah. THEY CHUCKLE

Oh, it's getting a bit more viscous, isn't it? Yeah.

So each of those little fibres in there is like a teeny, tiny

little sponge that's soaking up the apple juice? Yep.

The molecules are all going to start joining together,

and then that's going to create the gel.

Along with the natural fibres, stabilisers called carrageenans

are mixed in to give the lollies a creamy texture.

And the last ingredient is malic acid,

which is naturally found in apples

and gives them their distinct sour taste.

It's heated to 95 degrees, and then it's ready.

And it has a really lovely, tangy apple smell.

As it cools and hits the moulds, my lolly mix starts to thicken.

So they are going to go off to the freezer.

They just need to get to at least -18 degrees centigrade.

After eight hours in the freezer, it's time to taste the lollies.

I feel like I'm about to take a step into the future.

Cheers. Cheers.

Flavour's really lovely, appley.

The texture is a bit strange. HE CHUCKLES

A bit rubbery.

So the high fruit fibre content does affect the texture,

but will it stop it melting?

To find out, Danny and I have relocated to a hot house,

where we'll pit our future lolly against a traditional one.

It is a very balmy 32 degrees. It's hot.

We're going to time to see which lolly drips first.

As we release them from their freezer bags

filled with liquid nitrogen,

I'm backing the traditional lolly,

while Dan is rooting for his apple-green future lolly.

Right. Three, two, one - melt!

Which will drip first?

This could take a while.

Oh, my God. Quick, quick, quick, quick! Oh!

Eight minutes and 18 seconds.

And the drips keep coming, until...

Here we go!

Ah! Oh, what a splat!

It takes 15 minutes and seven seconds

for my lolly to hit the deck.

But Dan's future lolly is still going strong.

I think that makes you the winner.

I think it definitely does.

Well, look, on behalf of all the parents who do all the laundry,

congratulations and thank you.

My absolute pleasure.

So it's been an hour and 40 minutes,

and Dan's lolly is still going strong,

so maybe the days of a drippy lolly might be over,

but, personally, catching the drips is the best bit.

VARIOUS WHIRRING

In rural Scotland, we're six hours and 20 minutes

into making 5,000 tubs of ice cream.

I started with milk.

My mixture has been 50% frozen and pumped with air.

But there's still an important ingredient missing...

..honeycomb.

To create this sweet delight,

I'm meeting the factory's very own Willy Wonka, Louise Hunter.

Oh, I like the smell of it in here!

What is this place?

This is called the Sweetie Kitchen.

This is where we make the honeycomb. Ooh!

Listen, honeycomb is what I want.

Can I help you make it?

Yes, of course you can. If you grab that jug of water...

Water first?

Yes, you put it into here.

Louise makes all the honeycomb from scratch

in this 25kg copper cauldron.

Right. Now what?

Grab the two tubs of sugar.

So there is no honey in our honeycomb? No.

Is there a comb? No.

Just pour it in. OK.

Hmm. Well, that's me told.

Whoa!

Super sticky, right?

Yeah.

Next, we add seven kilos of glucose syrup,

which helps sweeten and thicken the mixture.

Just leave it sitting.

Oh!

The big cooker. That's like an electric hob. Yeah.

We heat it to a scorching 158 degrees centigrade,

so the sugar breaks down and caramelises.

How much honeycomb are we going to make in this bowl?

About 25 kilos.

Do you know how much honeycomb you make in the course of a year?

Yes, about 66 tonnes a year. Of honeycomb?!

Yeah! But your teeth haven't rotted.

SHE CHUCKLES No.

After cooking for 40 minutes,

it's taken off the heat, and things start to get dangerous.

Whoa!

The mixture is about twice as hot as a cup of tea,

and the copper helps to retain the heat.

So what's going in there? This is your bicarbonate of soda.

Bicarb contains sodium, carbon, oxygen and hydrogen,

and the heat of the caramel is crucial to what happens next.

The bicarb is actually what fizz up now, right? Yeah.

Is that all you put in there?

Yes, that's all it is. Really?!

And you just stir it up.

A mere 150g of bicarb is enough to trigger the release

of carbon dioxide...

Whoa, that is seriously hot in there.

..which is trapped within the sugar and causes it to expand,

forming a lovely, bubbly structure.

You've made a caramel mix with the sugar and the water.

Right. When you put the bicarb in, that's putting CO2 in the mix

and it's bubbling up, but, dangerous.

That's red-hot! It can be. You've got to be careful.

You wouldn't want to dip your foot in it. No.

SHE CHUCKLES

You're like one of Macbeth's witches. Exactly.

SHE LAUGHS

Stirring your cauldron!

You've got to work quick with that now, right? Yes, we do, yes.

It rises very quickly.

After three minutes of toil and trouble, we need some backup.

Who's this? Who's your friend?

This is Deirdre. She comes to help to spread it.

All right, Dierdre? I'm fine, you?

Whoa!

I've never seen so much honeycomb in my life.

What will we do now, spread it out across the table? Yeah.

It is hot like the sun.

It won't be hot for long because this metal cooling table

has pipes of cold water running underneath.

But we need to work fast,

otherwise the honeycomb hardens into, um...

..a sticky mess.

How am I doing? What do you reckon?

SHE GIGGLES

Can I see?

I'm not very good, am I?

THEY LAUGH

The honeycomb is left to harden at room temperature for 15 minutes,

but I don't think it's ready for my pot.

You can't get big lumps of this into a pot of ice cream, can you? No.

Just lift it up and break it.

Wait!

Oh, I like that! Oh!

I just throw one up in the air, let it break?

Yeah!

HE LAUGHS

Oh, brilliant!

What a job!

I feel like I've been to 100 Greek weddings.

Next, it's over to Deirdre's domain.

Deirdre, what's happening here?

I'm chopping the honeycomb into smaller pieces.

The chopper machine breaks down my honeycomb shards.

That's not a bad job, is it?

No, it's pretty good.

Then the chunks are sorted into different sizes.

So what is it sieving out, the big bits?

There's two sieves in here.

The big bits go to the factory for the one-litre tub ice cream.

The small bit goes for the small pots.

I've had a go at making it, I've spread out the hot mix,

nearly burnt my fingers, I've helped break it up,

I've shovelled it into the sieve.

Is it all right if I taste a little bit?

Yes, you can.

It almost fizzes, doesn't it?

Nice sugary crunch with a slightly bitter caramel finish.

Very, very nice indeed.

Before I eat any more, we sort the big bits into 10kg boxes.

Back of the net. You're good.

Yep. Yeah, we've got ten kilos.

How much of this am I going to need for my batch?

How many boxes? 22.

So I'll take this one over. Yes, please.

Deirdre, Louise, thank you very much.

I like it here. Thank you. Bye.

I just need another 21 boxes of this lovely stuff

to finish off my ice cream.

There are lots of flavours of ice creams these days.

Honeycomb, pistachio, choc chip.

But why stop there, when you can also add something special on top?

Cherry's finding out how one of these best-loved

embellishments is made.

One of life's great pleasures is ice cream with a topping.

And everyone has their favourite.

For me, my heart will always belong to the most colourful of them,

the sprinkle.

And today I'm going to find out the magic of how to make them.

Sprinkles were invented by confectioners

in 18th-century France.

Today, the UK's biggest producer is Cake Decor in Glasgow.

And Robert Simpson is their top man.

Am I about to learn the secret of sprinkles?

You are, yes.

Each vibrant colour is made in separate batches...

All right, let's get cracking.

..starting with the main ingredient, icing sugar...

That's a lot of sugar.

..175 kilos of it.

First, we haul it into a massive mixer.

It smells really nice, because it's all so fine,

and the air is full of sugar.

Next, we add gum acacia, a natural thickening agent

made from hardened tree sap,

to give my sprinkles strength and rigidity...

There's no elegant way to do this.

..followed by a mix of coconut and shea oil

to bind the fine icing sugar into a paste.

And finally, food colouring.

We're making orange.

My favourite.

This reminds me of my fake tan.

I think I'd probably get a little bit too orange if I used this.

Ready? Go on.

The orange colouring comes from unscented paprika concentrate.

It's diluted at a ratio of three-to-one with water,

before we carefully add it to the mix.

Oop, don't spill it.

After a 15-minute spin, it's ready.

Oh, my goodness me, that is beautiful.

It's crumbly and pasty.

180 kilos of orange sprinkle mix is then lifted onto a conveyor.

Ah!

In she goes.

And it's slowly forced through a giant strainer.

That...is so weird.

It's like a furry alien is trying to get through the sieve.

The sweet strands are just 1.3 millimetres in diameter.

So what do you call this machine?

So that's a vermicelli extruder, we call that.

Are you sure it's not called a "sprinklator"?

We could call it that. I'm pretty sure it is.

After leaving the "sprinklator",

my orange strands are sent through an eight-metre-long tunnel,

which blows room-temperature dry air onto them until they're touch-dry.

Then they're left in a drying room for a further 24 hours

before they arrive here.

What is this amazing machine?

So this is a coating pan that we use to break the product down.

So what's the perfect length?

We're looking for between three mils and 12.

Yeah, that one's about right.

Back you go, you're not ready, sprinkle.

It's a bit like a fairground ride.

CAROUSEL MUSIC PLAYS

Hold tight.

MUSIC CONTINUES

That is mesmerising.

I can't take my eyes off it.

A shiny coating of sugar syrup is added to stop the colour running.

It crystallises into a hard shell as it's dried for three minutes.

It's like a hairdryer. Exactly, yeah.

That's great!

Not very portable, not good for holidays, but fine at home.

So, last thing is beeswax.

The edible beeswax seals the sprinkles

and stops them from sticking together.

So, have we finished the sprinkles?

The orange ones are now 100% ready to go,

but we don't want just orange,

so we've got another four colours to go in this one.

Lift off!

The moment I've been waiting for.

Oh! Oh, ho, ho!

Wow, that is beautiful.

That is even cooler than I thought it would be.

Incredible. You almost get every colour of the rainbow happening.

It's beginning to look a lot like sprinkles.

They make 50,000 pots of these gloriously coloured sprinkles

every single day.

Dipping an ice cream into a big bowl of sprinkles

is just one of life's great and simple pleasures.

Next time I get to do that, I love that I will know

how much work and precision has gone into making them.

Over in Aberdeenshire, I'm nearing the end of my ice cream production.

I've made some smashing honeycomb,

and the creamy mix has been half frozen,

so it's flowing through the pipes to the filling area,

ready for production manager Morag Haggerty to bring it all together.

Morag! Hi, Gregg. Can I put these down? Yeah.

Right down there.

Where are we?

We're in the filling room. Filling? Yeah.

What, like when you go to the dentist? Yeah.

SHE LAUGHS

This is where the ice cream actually goes into the tubs.

So what happens to my honeycomb?

So, we put it in here.

Straight in? Yep.

I love this stuff. The smell is incredible, isn't it?

Yeah. All in.

And then what happens to it?

So, the honeycomb goes into the hopper,

it mixes with the ice cream.

So you must have to keep filling this thing all day!

Yes, every five to seven minutes.

You must be built like a weightlifter.

How much honeycomb goes into every pot?

This much, Gregg.

That's quite a bit. Yep.

So as the ice cream flows, what, it's just a pinch each time? Yes.

Enough honeycomb is added to ensure there's a crunch in every spoonful.

And then the 50% frozen ice cream is ready for the tubs.

So what's the first job here, make sure you've got enough pots?

Can you put in some tubs, please? Straight in? Yep.

You actually go through those really quickly, don't you? Yeah.

How quickly? How fast is ice cream coming down here?

We're doing 58 tubs per minute.

58 tubs a minute. Ooh, crikey!

Good job someone's watching, isn't it?

How do you know for sure that the honeycomb

hasn't gone all the way down to the bottom?

We can tell by eye.

It's the ripple and nipple effect, Gregg.

What do you call it?!

It really is called ripple and nipple.

Go on, what is that?

We have a ripple across the top,

and then the nipple in the middle.

It shows us that we've got the right amount of air in the ice cream

to give us the correct viscosity.

And that ensures that the honeycomb is mixed throughout the pot.

Ripple and nipple.

I love that.

And now my ice cream is fully flavoured,

I can't resist another taste.

That is lovely!

Cos it hasn't dissolved, it hasn't dissolved,

it's still got crunchy bits.

I kind of like it half frozen.

I'm so happy!

You seem at home here. How long have you been here?

20 years.

No way! Yeah.

Is it fun? Sometimes. SHE CHUCKLES

Is it stressful? Sometimes.

Mm!

This is dangerous.

Yeah. Are these ready to go now?

No, we still have another freezing process to go through.

I'll put this down, before I eat the whole pot.

With the perfect ripple and nipple on my ice cream,

vacuum suckers add lids to my pots,

before they're sent through the wall into an ominous-looking chamber.

To follow them, I need to dress the part.

Morag, how come you haven't got a balaclava or woolly hat and gloves?

I'm a good bit heartier than you are, Gregg.

Wow! Any penguins? SHE LAUGHS

How cold is it in here?

It's as cold as the Arctic in winter.

No wonder polar bears don't smile!

SHE LAUGHS

As tall as a house, this freezer is -35 degrees Celsius,

nearly twice as cold as the one you or I have at home.

That is seriously, seriously cold. What is happening?

We need to get the ice cream down from -5, remember, to -18.

Why do you want it at -18?

That's the temperature we need for it to be 80% frozen.

This is the final freezing process.

At 80% frozen, the ice cream is still scoopable,

but the ice crystals remain tiny,

ensuring a creamy and smooth final texture.

But it's not just a funfair for ice cream pots, is it?

No.

The journey along the spiral takes an hour and a half,

and every hour an incredible 7,000 litres spin by.

Where do they go when they've got to the end of this spiral, then where?

Into final pack.

Is final pack warmer than this?

Yes, it is. Let's go.

You have to go through that to enjoy a pint of ice cream.

My ice cream exits the freezer for the final leg of its journey.

Now, ice cream has been around for a lot longer than high-tech freezers.

So how did we keep it frozen before the days of electricity?

Ruth has been finding out.

In the 1800s, Park Crescent in London

was home to the Georgian elite,

who had indulged in extravagant dinners,

including the delights of ice cream.

But to enjoy ice cream, they needed...ice.

Only the very wealthy could afford ice.

You had to pay handsomely for it in the first place,

and then you had to work out how to store it.

How on earth did they do that?

The modern-day Park Crescent holds the answer.

During recent redevelopment,

the build team came across an intriguing underground structure.

Hidden deep beneath the site was an historic ice house.

SHE GASPS

Oh, my goodness, that is enormous! Huge, isn't it?

Danny Harrison from the Museum of London Archaeology

is in charge of the excavation.

This would hold several hundred tonnes of ice.

It will stay frozen in the ice hole for a whole year.

This vast, hand-dug cavern is nine-and-a-half metres deep.

Built in the 1780s,

it stored ice collected from local canals and lakes.

Unsurprisingly, the ice was dirty from the polluted water,

and the supply depended on cold British winters.

They needed to start bringing in a reliable source of ice into London.

So, when does that happen?

Our first records of that is the 1820s

with a man called William Leftwich,

who brought it from Norway.

And that initial speculative venture turned into a real business.

Leftwich was a confectioner and entrepreneur.

He quickly recognised the soaring demand for ice,

and in 1822

shipped 300 tonnes of pristine ice from the fjords of Norway

direct to London.

This is from the 1826 morning post,

and Leftwich frequently advertised, throughout the 1820s,

his wonderfully clean ice from Norway.

He said it was so clean you could actually drop it into drinks.

So this is something a little bit more reliable.

Absolutely, and by the end of the 19th century, we're talking hundreds

of thousands of tonnes of Norwegian ice coming in.

And it starts to become very affordable.

And suddenly you wouldn't have a world without ice. Yeah!

This is it. Ice is here to stay.

The supply of imported ice rocketed,

and suddenly ice cream became available

to a whole new Victorian market.

At the London Canal Museum,

I'm meeting food historian Polly Russell

to learn about a pioneering woman who became known as the Ice Queen.

Hi! Hello!

There was a woman called Agnes Marshall.

This is a very smart, savvy entrepreneur,

and she produced this most beautiful book in 1894

called Fancy Ices. Fancy Ices.

She also patented the first ice cream maker for the home.

Marshall's patent freezer.

This ice cream maker was revolutionary,

claiming the dessert could be made at home in a matter of minutes.

Using a replica, we're going to give it a go.

There's no, sort of, like, mechanical freezing.

I mean, it's not like... No, no, we're going to create ice cream

with salt, and ice, and a custard and some fruit.

It is sort of miraculous, isn't it? SHE CHUCKLES

Using Marshall's recipe for cherry ice cream,

first we make a custard base,

heating double cream, sugar and egg yolks.

We leave it to cool and move on to the all-important flavour.

We've stoned the cherries, and we're going to put them in a pan.

The cherries are heated, then lemon juice and carmine,

a natural food colouring, are added.

And after they've cooled, all the ingredients are combined.

That's our mix. Yeah.

Now we need to add salt and ice.

Surprisingly, it's salt that's the key element here.

Now something magic happens.

That is the technical term - magic.

SHE LAUGHS

You'd be right in thinking that salt melts ice.

But here, as it dissolves in the water droplets,

it changes its freezing point.

The melting ice absorbs energy, so it gets even colder.

When we pour in our mix,

its temperature drops to -6 degrees.

Lid on.

Locking bar.

We're in business.

Churning adds air and folds the mixture,

encouraging it to freeze evenly.

Ugh!

Is that hard work? I'm glad I've got a partner in crime to hand over to.

And after a final churn, it's the moment of truth.

Oh, my goodness.

Look. Ooh.

It's a soft scoop. It's a soft scoop.

That's so good. That is so good!

And imagine this in a 19th-century house.

Long before electricity.

Yeah! This would be magic.

No longer the preserve of aristocratic houses

or professional confectioners,

Agnes Marshall made home ice cream making accessible to anyone

who could afford the eggs and cream.

Back at the factory, my ice cream has been frozen to a perfect 80%.

And it's time for a few final checks.

Oh, it's getting colder.

You got it.

-18.5.

Brilliant. Right. Now you know you've got the right temperature,

now what do you do?

Now I want to cut it up to make sure that honeycomb

is right through the tub of ice cream.

What are you doing?

You'll never get that out there.

Well, hey!

There we go.

Whoa!

There is plenty of crunch in that.

Yep. Can I taste it now?

Yep!

I've tasted it every step of the way here, haven't I?

All the creamy flavour's there and the sugary flavour of the honeycomb.

I can't leave the stuff alone.

Now we're ready to pack.

Oh! I love packing.

I really do. Right, what's happening here?

So they're coming out of the spiral freezer,

along the conveyor, into the shrink-wrapper,

where they're getting wrapped into sixes, and then onto the pallet.

A heated tunnel is hot enough to melt plastic. Yep.

Hang on a minute, ice cream in a heater?

This thing is 186 degrees!

How long are the tubs of ice cream inside the tunnel

that's melting the plastic?

Just seconds, Gregg.

Not enough to melt -18? No. Right, got you. No.

And you're sure of that, obviously. Yes, yes, definitely.

And how fast do we pack it?

Nine packs a minute.

Nine packs of six? Yeah.

How many tubs are we going through here?

156 cases of six on a pallet.

Ah!

My maths can't do that.

936.

From here, the tubs head to a cold store,

where they're kept at -25 degrees,

and after 30 hours, my honeycomb ice cream

is arriving at dispatch.

That's my batch that fella's loading on the truck, is it?

Yeah, it is.

That is a pretty sight. Yep.

How much have we got on here?

There's 26 pallets with 156 cases on each pallet.

So it's about 24,000 tubs of ice cream here.

HE CHUCKLES

Not even I could eat that much ice cream!

I'm taking it for granted, this is a chilled lorry.

Yes, of course, it's -18, so it'll keep our ice cream perfect.

Right, OK, and how often does a truck leave your factory?

Anything from three to five trucks a day.

Seriously, that much? Mm-hm.

Why is it that we love ice cream so much?

Just makes you feel good. Yeah, I agree.

Should we let your guy finish loading the truck?

Yeah, let's go.

OK, Graham!

Thank you, Morag.

Us Brits love ice cream,

and apart from me, it's Scotland that eats the most.

And the creamy delight travels as far as Taiwan and South Korea

and is enjoyed throughout China.

They make a lot of ice cream here,

and I've been savouring it every step of the way.

That is lovely.

I've had a smashing time...

Yeah!

That is brilliant!

..with moments that have given me chills.

Whoa! Any penguins?

SHE LAUGHS

But what I think is really impressive is all the milk

for the ice cream comes from their own herd of cows,

who milk themselves whenever they want!

Now, that's incredible!