After scientifically determining the Bloody Mary is the world's most complex and unstable cocktail, scientists have made another major breakthrough: identifying the main substances that cause the bitter, harsh aftertaste of aged beer. It's good to know science is working on the important problems.
Experts estimate that the average beer goes bad after 6 to 12 months of storage. (You don't have to earn a PhD in biochem to know that.) Researchers analyzed a variety of commercial beers before and after storage. They identified 56 substances — mostly prenylated polyketides derived from hops — that contribute to beer's bitter taste. In specific, five of these appear to be largely responsible for beer's harsh flavor after aging. The findings appear in American Chemical Society's Journal of Agricultural and Food Chemistry.
Preventing the formation of these prenylated polyketides could have several important commercial applications.
The study concludes:
“The present study offers the scientific basis for a knowledge-based extension of the shelf life of the desirable beer's bitter taste and the delay of the onset of the less preferred harsh bitter aftertaste by controlling the initial pH value of the beer and by keeping the temperature as low as possible during storage of the final beverage.”
In layman's terms: They're going to use the results of the study to figure out ways to keep beer fresh longer. Duh.