Cold trub

Wort freed from spent hop material and trub is cooled in order that it can be pitched with yeast. In very old breweries, the wort is cooled in shallow open vessels, using only air cooling. These open coolers or coolships had three functions cooling, aeration of the wort and separation of cold trub. 

A recent survey [30] has shown that in Swiss breweries, the cold break content of beers varied over a wide range, independent of separating procedure. The effects on fermentation, maturation and beer clarification were not significant.. During the course of successive fermentations, the preference of tasting panels shifted from beers where cold trub had not been removed... 

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