http://www.azcentral.com/arizonarepublic/local/articles/0907clay07.html
Light beer, good; light + beer, bad
Sept. 7, 2004 12:00 AM
T oday's question:
I bought a few cases of cold beer for a party to be held in a few weeks. It was cold when I bought it, but I have had to store it at room temp, and plan to ice it down on the day of the party. A friend said this is a no-no, as beer once cold, then warmed up, then cooled down becomes bitter. Is this true?
While I was looking this one up I came across a recipe for pancakes made with ale. That sounds pretty good, but now I can't remember where I found it.
I'll look it up again later. Right now we have to deal with the cold-warm-cold thing. This guy didn't say if he bought bottled beer or cans. If he bought cans, he's probably going to be OK. If he bought bottles, it probably depends on how he stored it.
A lot of people believe the cold-warm-cold thing makes beer taste bad or lose its carbonation. I always thought that, too, but then I am just a country lad unversed in the ways of the world.
In fact, it takes really extreme temperature swings to affect the taste.
It turns out that the real villain when beer goes bad is light. That's how you end up with bitter beer, sometimes called light-struck or skunked beer.
OK, beer contains hops, some more than others. Hops are what make beer taste like beer.
The problem with hops is that they contain something called isomerized alpha-acids. When light hits beer, it sets off a photochemical reaction that changes those isomerized alpha-acids into something else. Specifically, what you get is 3-methyl-2-butene- 1-thiol.
This is very similar to the chemical in skunk spray that makes it stink. This is very bad. After a long, hard, hot day of doing whatever it is you do, a beer that smells like a dead skunk is not exactly going to hit the spot.
Blue light, I am told, is the worst, which I suppose is why very few beers seem to come in blue bottles. Green light also is damaging, and of course, clear bottles let in all the light so they're very prone to skunking. Brown bottles are the best, but as long as some light is getting through, there is going to be some skunking going on.
Some brewers, including Miller Brewing, I think, have found a way to get around this problem. It is a hop extract known as tetra-hop. Tetra-hop is built a bit differently than regular hops and doesn't react the same way when it's hit by light.
Reach Thompson at clay.thompson@arizonarepublic.com or (602) 444-8612.