Kräusening

Krausening: Introduction of actively fermenting beer to more thoroughly fermented beer. (Taken from "The Brewmaster's Bible" by Stephen Snyder)

Kräusening

Kräusening is the traditional method German brewers use to carbonate beer. The process consists of adding freshly fermenting wort to beer that is ready to bottle. Kräusening overcomes the problem of yeast going dormant. It helps clean up the flavor of the beer by reducing levels of diacetyl and acetaldehyde.

Traditional German Kräusening

In a traditional German brewery, kräusening is done by adding a bit of the most recent batch of beer to the batch that was made about six weeks earlier. If you make the same style of beer every six weeks, this method works well.

Modern Brewing

Advances in brewing science have created a situation whereas brewmasters have shortened the time required to deliver fresh beer. Today, most breweries force carbonate beer after filtration, to remove yeast and other sediment, then bottle the beer under pressure. CO2 is injected directly in the beer. This allows the beer to be consumed as soon as it's packaged.

References

[1]Redwood Avenue Picobrewery - Ask the Brewmaster
[2]Hair of the Dog Brewing Company Bottle Conditioning
[3]The Brewmaster's Bible: Gold Standard for Home Brewers ISBN:978-0060952167