Strains of Saccharomyces cerevisiae or Saccharomyces pastorianus selected for their ability to consume malt sugars and produce alcohol, carbon dioxide, and desirable flavor compounds. In a production context, it refers to the active slurry pitched into wort. In the food processing sector, it also refers to the spent, deactivated yeast cells recovered after fermentation, which are debittered and dried into a nutritional powder rich in B vitamins.
The brewer's yeast from tank four is starting to lose viability, so we need to propagate a fresh pitch for the next batch.
Related terms
Yeast-bitten
Describing a beer that has taken on harsh, bitter, or meaty off-flavors from prolonged contact with dead yeast.
Attenuate
To consume dissolved sugars during fermentation and convert them into alcohol and carbon dioxide.
Turbo yeast
A specialized blend of highly alcohol-tolerant yeast and chemical nutrients designed for rapid fermentation.