Why Beer Goes Bad: The Latest

beer8380.jpgI’m a veteran of graduate school social events, so the concept that the party is over when the alcohol runs out is firmly entrenched in my psyche. As a result, I was a tad overzealous the last time I bought beer for a party. To be honest, several cases were left over. Now, months later, I still haven’t finished the beer. The thing is, I have this nagging guilty feeling about serving my friends old beer or bringing it with me to their parties. I’ve done a pretty good job of following basic rules for keeping beer fresh. But some new research in the Journal of Agricultural & Food Chemistry suggests that beer aging could be nipped in the bud just by using the right additives. The reference: “Formation of alpha-Dicarbonyl Compounds in Beer during Storage of Pilsner,” J. Agric. Food Chem. 2008, 56, 4134. The research team behind the study, led by Adriana Bravo at Empresas Polar, Venezuela's best-known brewery, in collaboration with researchers at the Universidad Simon Bolivar, in Caracas, says the brewing industry’s focus on minimizing oxygen during the brewing process hasn’t dramatically improved beer flavor stability. They identified a group of alpha-dicarbonyl compounds, products of carbohydrate degradation, that go on to become aldehydes that contribute to “aged” beer flavor. They also showed that by specifically trapping alpha-dicarbonyls with 1,2-diaminobenzene, formation of some offending aldehydes was significantly blocked, even when they heated the beer to 60 °C for three days. Table 7, for me, is the highlight of the paper. The researchers list the effects of 1,2-diaminobenzene on various odor-causing compounds present in old beer. Check out the column of odors assigned to the various compounds. It's a veritable treasure trove of descriptive words like fetid, rancid, solventlike, plasticlike, and more. None of those are really something I'd want my beer smelling like, but it called to mind a classic Tenderbutton entry about how hexanoic acid smells like goats. I don’t think this is a miracle beer-preserving strategy just yet. On the second-to-last page of the paper I read this sentence: “The impossibility of ingesting the beers spiked with 1,2-diaminobenzene to perform sensory analysis was overcome by the use of GCO analysis of the beer headspace using SPME.” Sounds like they didn’t want to taste-test that beer for some reason. Maybe the next step will be to make other compounds that can trap alpha-dicarbonyl compounds and taste test the effects of those. This certainly isn’t the first study on the chemical mechanisms leading to bad beer (see here, for instance), and the findings come too late to help my batch of brew. But with a little creative chemical thinking, forever-fresh beer could be in existence by the time my retirement party rolls around. I’ll drink to that. Photo: Courtesy of public-domain-photos.com UPDATED 6/16: to include corresponding author and institutions

Author: Carmen Drahl

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3 Comments

  1. i read with interest the above regarding the use of 1-2-diaminobenzene to improve the beer stability but , you do not mention the names of the venezuelan team. For any researcher is very important to be recognized with his name when some magazine publishes his job

  2. Thanks, Luis. I’ve updated to include that information.

  3. Personally, I’m a veteran of undergraduate social events, events pre-18 where there wasn’t supposed to be any booze, and even early-teen events where there really, really wasn’t supposed to be any booze…