What are polyphenols primarily found as in brewing?

Polyphenols are primarily found as tannins in brewing. Tannins are a specific group of polyphenolic compounds that contribute to the astringency and bitterness of beverages, particularly in wine and certain styles of beer. They are derived mainly from the malt, hops, and even the water used in the brewing process.

In addition to their sensory contributions, tannins also play a role in the stabilization and clarity of beers through their interaction with proteins, which can help precipitate particles and improve clarity over time. The presence of tannins is significant for flavor complexity, mouthfeel, and even the longevity of a beer, as they can help preserve freshness by providing antioxidant properties.

Tannins should not be confused with sugars, proteins, or amino acids, which have distinct roles in brewing. Sugars are primarily fermentable carbohydrates that yeast convert into alcohol and CO2. Proteins are large molecules that have various functions, including forming part of the structure of yeast and other cells but do not primarily include polyphenolic structures. Amino acids are the building blocks of proteins and are involved in flavor development and nutrient provision for yeast, but they do not represent the polyphenolic fraction that is primarily categorized as tannins.