Skeptical Brewing

This article originally appeared in the November/December 2021 issue of Zymurgy Magazine

By Leandro Meiners & Matias Cavanna

Cohumulone is one of the chemical analogues (aka one of the many compounds that are similar enough to all be included in the same family) that make up alpha acids. Hence, it appears in beer as one of the iso-alpha acid forms. It has a bad reputation among many brewers: hops high in cohumulone (in proportion to the rest of the analogues that make up alpha acids) are said to confer a “harsher” bitterness, normally considered unpleasant.

This statement originates from a 1970s paper called “A theory on the hop flavor of beer” by Rigby, a fact that is confirmed in the recent review on hop chemistry by Ting and Ryder. It is worth recalling that Rigby first described alpha acids in the 1950s, as well as isomerization and their important role in the bitterness of beer.

Rigby’s work had marked repercussions in the hop industry: it unleashed an international demand for varieties low in cohumulone, with its consequent impact on hop breeding programs for new varieties that sought to respond to this demand. Furthermore, Stan Hieronymus, author of For The Love of Hops, maintains that it even explains why suppliers usually indicate the percentages…