Claudia Romeo: Flaky layers, lots of butter,

and a delicate crunch.

These are what makes a freshly baked croissant

absolutely irresistible.

It's a beautiful morning in Nice, on the French Riviera,

and I can't imagine a better way to start my day

than having a croissant.

I personally cannot imagine anything more French

than a perfectly laminated dough and,

if you know this series well, butter.

Lots of butter.

We're going to find out more.

I know we promised you butter,

and we'll get to that in a bit,

but aren't you curious to learn

how croissants get their perfect flaky layers?

Sit tight, because it's going to take three days.

At least, that's what happens in real life.

Luckily for you, we're here to speed things up.

Day one is the day of the dough.

We need sugar, salt, water, yeast,

leftover dough, and flour.

Claudia: This dough contains 8 kilos of flour

and will make about 240 croissants.

And this is only one-third of the daily production

here at Boulangerie Roy Le Capitole,

where over 1,000 croissants a day

are churned out during the weekend.

Frédéric even supplies the most prestigious hotel in Nice:

the Negresco.

The dough kneads for 12 to 14 minutes,

just enough to gain elasticity,

but not too much to heat up

and kick-start the fermentation process too soon.

This, in baker terms,

is called preserving the gluten network.

It's what Frédéric is showing me here:

The dough is not breaking nor stretching.

Once it has been divided into patons,

which literally means "pieces of dough,"

it is placed in the fridge and left until tomorrow.

Day two is the day of the butter.

Our favorite ingredient will take up

as much as 30% of the croissant pastry,

but butter is not mixed with the dough.

The two have to be perfectly layered.

Claudia: This is how lamination works.

The layers are achieved by, you guessed it,

folding the dough and butter over and over again.

To do that, there are two kinds of folds or turns.

A single fold, where the dough is folded in thirds,

like an envelope, gives three layers,

whereas a double fold,

where both ends meet in the middle

and then are folded again, like a book,

gives four layers.

A baker can choose whichever technique they prefer.

Frédéric starts with a single fold,

single again, and then double.

Claudia: As the lamination process heats it up,

Frédéric puts the dough in the fridge

for half an hour to keep it cold.

Keeping the dough cold and firm

is essential for what comes next:

cutting it in the tiny triangles

that will be our croissants.

You may think the croissants are ready to be baked,

but we actually need to wait another 15 hours

for that to happen.

Following Frédéric's step-by-step process

really made me appreciate how much time and energy

goes into producing the perfect product.

Do you remember the baguette tradition?

This type of baguette, by French law,

has to be made on-site with simple ingredients.

Well, for the last four years,

Frédéric has been campaigning

to get croissants the same protection.

Claudia: It's day three of our croissants.

Three, like how they grow three times their size

when they're baked.

[timer beeping]

[crackling]