The foamy, dirty head of bubbles, yeast, and fermentation by-products floating on the top of an actively fermenting beer. Some believe that removal of the krausen improves the final beer's flavor. Since the krausen has a tendency to clog airlocks (sometimes leading to exploding fermentors), blow-off tubes can be substituted during primary fermentation. "Krausening" refers to the addition of freshly fermenting wort (that is, wort with a krausen) to a previously fermented batch just before it is bottled. Krausening will carbonate the packaged product, and produce a freshness of flavor not found in artificial carbonation methods or natural priming with residual yeast.

Krausen the cool brewing term for the layer of foam and gunk which forms on the top of your beer as it begins fermentation. It is pronounced "KROY-sen." For example, it is best to pitch your yeast starter at high krausen.

A traditional technique of carbonation is to add a small dosage of unfermented malt sugars to the conditioning tank. The wort ferments out and the beer is conventionally filtered.

KRAUSEN - (German) Traditional technique of carbonation in which a small dosage of unfermented malt sugars (wort, in English) is added to the conditioning tank. In normally Krausened beer the wort ferments out and the beer is conventionally filtered.

the ugly foamy head that appears on new beer as it ferments. This is a good thing.

Used to refer to the foamy head that builds on top of the beer during fermentation. Also an advanced method of priming.