The Invisible Beer Molecules – Episode 2 — The Beer Foam.

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Beer foam is not just aesthetic.
She is chemistry.

That white collar that forms at the top of the cup is supported by a delicate network of molecules—mainly Proteins from malt.

During the beer production process, some proteins survive mashing and fermentation.
These proteins have hydrophobic regions capable of interacting with the Iso-alpha-acids of hops, forming structures that stabilize CO₂ bubbles.

The result is the foam we see in the glass.

But the function of these proteins goes beyond appearance.

They directly influence:

• the Foam persistence
• the beer texture
• the Retention of aromatic compounds

That’s why different styles have such different foams.

A hefeweizen usually has abundant and creamy foam, thanks to the high protein content of wheat.
A stout can have an extremely dense and stable foam, especially when served with nitrogen.
Meanwhile, a Pilsner seeks an elegant and persistent foam that will accompany the crystal clear clarity of the beer.

In the end, each bubble that forms in the foam is supported by an invisible molecular architecture.

And understanding this architecture shows us something fascinating:
Beer foam is a visible manifestation of chemistry that takes place inside the glass.

This is the Episode 2 of the series ‘The Invisible Beer Molecules’.

In the next episode we will explore another fascinating phenomenon of brewing science:
When turbidity ceases to be a defect and becomes an identity—the famous haze of modern IPAs.

Do you usually observe the beer foam before the first sip?

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Maria Anita Mendes
Beer Sommelier | PhD in Science
Newsletter author Entre a espuma e a molécula

#beerscience #artesanal #brewingscience #sensoryscience #sommelierdecerveja