M-52: A simple, quantitative approach to beer freshness

M. D. KOPPELMAN (1); (1) Badger Hill Brewing Company, Minneapolis, MN, U.S.A.


Beer is a perishable product, and brewers spend a considerable amount of effort managing freshness and setting freshness expectations for their customers. Here we present a simple, quantitative approach to freshness in a unitless ratio, referred to as the “freshness ratio,” which is the total amount of heat experienced by the beer, in units of degree days, with respect to the maximum amount of heat allowed according to the specification of the brewer. A brewer may determine that a given beer expires after 120 days at 3°C. The freshness ratio implies that the same beer would expire after just 18 days at room temperature. This allows quantitative analysis of processes and even, perhaps, detection of heat exposure in the form of a “freshness badge” on the product itself.

Michael Koppelman is head brewer at Badger Hill Brewing Company, a small, growing brewery near Minneapolis, MN. He is a graduate of the American Brewers Guild and also has degrees in music (Berklee College of Music) and astrophysics (University of Minnesota). He was formerly a record producer and engineer for artists such as Prince and Booker T and the MGs. His entrepreneurial pursuits include being a founder and principal at Clockwork Active Media Systems, a digital agency also in Minneapolis. He has been a home brewer since 1985 and has a special interest in pale ales.

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