I've been busy lately not with brewing or school but with work, frisbee golf, and fly-fishing. The latter two sports have one thing in common--they're both best accompanied with beer. A cold IPA is almost a requirement for scoring under par, and a few sips before each cast creates an odd attractive force around my fly that makes every trout in the stream swim after it. There is however some skill involved in gulping beers on the river or at the frolf course; the beer must be either hidden from the sun or drunk quickly before UV rays react with the hop material to turn your tasty IPA into liquid skunk--known as light-struck or "skunked" beer. If you are wondering what I mean by skunked beer, buy a bottle of light-beer in a green or clear bottle and set it in the sun for an hour before you drink it. I've read that the transformation can occur within 15-minutes under intense sun light. Heineken has a reputation for being skunked, which can be attributed to the green bottle its packaged in. Green and clear bottles will allow more sun light to penetrate the beer while brown bottles minimize light exposure.
The chemical explanation for skunked beer is that hop material such as isomerized humulones are broken apart when exposed to high energy light waves. Portions of the ruptured molecules can then react with a sulfur compound readily found in beer to form a molecule that is almost identical to that found in the aroma produced by skunks. Hops can however be treated with sodium borohydride to reduce them to a more light stable form that does not break down as easily--Miller treats their beer with this to keep it from skunking.
So next time your drinking beers while frolfing keep this information in mind. I've found that if my beer becomes skunked my accuracy deteriorates and my score card fills up with bogeys.
