take you to see how Gorgonzola cheese is made in Italy.

I'm in Trecate in the Piedmont region,

which is one of the only two Italian regions

together with Lombardy where this cheese can be made,

and this is one of the only 29 dairies

in the world that can produce this cheese.

The Gorgonzola industry is worth over $800 million.

Almost 5 million wheels are produced each year,

and production is confined to this small area only.

Gorgonzola cheese has a centuries-old history,

and it is still done using the same

ingredients and techniques that it was decades ago.

Even machines like this one used to stir the curd are

designed to recreate human movements as gently as possible.

Its beautiful marbled interior is given

by Penicillium roqueforti, a fungus that

is used to ripen the cheese.

And this is why, in fact, blue cheese is called so.

- Claudia: Gorgonzola cheese is made with unskimmed

pasteurized cow's milk, and it can either be

mild and creamy or hard and pungent

depending on how long it is left to age.

The two kinds are easily distinguishable by

the color of their veins:

blue in the creamy and green in the pungent.

Claudia: Penicillium roqueforti, the fungus, is added

to milk at the very beginning of the production process

in a big cauldron together with enzymes, rennet, and yeasts.

In about 20 minutes, milk becomes curd

and can be transferred into molds.

Each wheel is marked with the dairy's identification number.

You can see number 60 here,

that's Caseificio Si Invernizzi we visited.

Here, between 450 and 500 Gorgonzola

wheels are made every day.

To help the curd settle, wheels are turned four times

then left to rest overnight.

Then, they are salted a couple of times.

At this stage, they weigh about 18 kilos,

that's 40 pounds, but this number will drop

to 12 kilos, 26 pounds, at the end

of the aging process as excess whey is released.

The salting rooms are warm and humid.

This is also to favor the activity

of yeasts inside the cheese.

Mild Gorgonzola wheels stay for three days

and hard Gorgonzola for five.

Then, they are moved again into a cold room

where they're punctured 100 times on each side.

This is to allow oxygen into the cheese

for it to grow its signature blue veins.

All Gorgonzolas at Caseificio Si Invernizzi are

punctured with a machine, but some other

in-house cheeses are still punctured by hand.

After this step, the cheese is left to age.

It takes two months for the blue creamy Gorgonzola

and three months for the green pungent one.

The color difference is pretty evident,

but do they really taste different?

The dairy set up a little cheese tasting

so that we could try them both.

That's amazing, my God. It almost doesn't feel

like you're biting

into cheese. It just melts in your mouth.

Oh, wow, they are so different. It's crazy. You know?

I mean, you can tell from the texture

that this is harder and this is creamier, but

this is much, much stronger. It has a stronger bite.

After trying Gorgonzola on its own,

in-house chef Gianpiero Cravero

wanted to show me how versatile the cheese is,

so he cooked some squid ink spaghetti with both cheeses.

- Your pasta.

- Mmmm. Wow. The cheese tastes very strong,

but I think the combination with the squid ink

is great. I mean, color-wise of course it's amazing

because black and white, they're like opposites, right?

So you can really see the cheese in there

and its sort of creamy texture on the pasta.

Gorgonzola cheese is protected by the European Union

by the Protected Designation of Origin Scheme.

This means that any cheese labeled "Gorgonzola"

must meet a particular set of standards

and is subject to quality checks.

It's also wrapped in a signature aluminum foil.