What is krauesen?

[Lando]

Some of my beers and starters develop it, some don't. What is the reason for this? What is in it?

 

[killian]

yeast.....

 

[Lando]

Then why don't we call it yeast?

 

[Mountainbeers]

Krausen is just what develops in the most active stages of fermentation. If you have a slow fermentation you might not develop any at all. Likewise if you have a fast one you might have blowoff. It's just CO2 mixed with nasties and well I don't know what else.

 

[menschmaschine]

The true German speakers can correct me, but kraus means frizzly, so krausen must be a plural noun meaning "frizzlies". Your beer has a case of the frizzlies.

It's CO2 carrying up yeast and wort compounds (proteins, etc.) forming a foamy head similar in concept to what happens when you pour your beer in a glass.

 

[david_42]

Krausen is nothing more than a big, hop-infested head. The more active the ferment, the more likely you'll have a big one. Slower ferments, the bubbles burst before they can build up.