A while back I asked my cousin Mike to write an entry for me. Mike is currently working on his PhD in Chemistry at the University of Wisconsin - Madtown (Madison). Mike is an extremely smart individual so before writing I asked him to drink a beer or 4, then compose. Well, last night I got an email with his entry. I'm pretty excited. Real quick let's review Mike's qualifications... Czech heritage.. Check! Grandfather grew barley for Coors (R.I.P. Grandpa Joe. Miss you!)... Check! Lives in Wisconsin.. Check! Enjoys beer... Check! Has a degree in chemistry.. Check! Ok.. I think he qualifies. On to his entry:
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Light Beer?
Beer is delicious. Let’s get that out there first. I may be weird, but I drink beer because it tastes great! I don’t drink because it gets me drunk (an unfortunate side effect of the beverage), or because it is healthy (how many Miller Lites can be burnt off in one 10 k road race?) or because it is the socially acceptable thing to do with my friends (my two best friends cannot or do not drink alcohol for various medical and personal reasons). I drink beer because it tastes so damn good. Hence, like Ryan, I have begun a career in drinking craft brews. If I’m only going to drink one to two beers in a given night of “heavy” drinking (yes, I don’t drink much), I’m going to drink something that is possibly going to give me an out of body-, virginity losing-, finding Jesus-like experience. Bud Light probably isn’t going to get that done for me.
Phew. Glad I got that off my chest. Now to my true specialty: chemistry. Beer is arguably the reason why my field exists in the first place. The pH scale (measure of acidity/basicity) was developed in 1909 to assist in control of wort production (this work was done at the Carlsberg brewery/ laboratories, yeah, pretty much a dream job. They give a daily beer ration of a 6 pack a day, or so I’ve been told by chemists who would know). Louis Pasteur (the guy that pasteurization is named after) studied bacteria in beer, and developed his famous process for beer production, milk go eat your heart out. The reality is that you cannot (in my opinion) truly understand and appreciate a beer without understanding some of the science behind it, and in it.
Ok, quick disclaimer. I am a scientist. Currently I would be described as a bioorganic, biomaterials chemical biologist. I used to do speciation/evolutionary studies in entomology. I make my living by trying to understand things in the world around me that no one else understands yet. And that sort of mentality cannot be left in the laboratory if you truly are a scientist. You take it to the tap room after work, too.
So, let’s start with something that I hold as scientific truth, and even my cousin (whose knowledge of beer I greatly admire and respect) may disagree with. Beer tastes best out of a keg. Ok, I know Ryan agrees with that. Beer taste second best out of a can. Yeah, I went there. Beer taste third best out of a bottle. Now good beers generally are sold in bottles and the awful cheap stuff tends to be sold in cans, but if we throw out that trend, I feel this order holds true.
Here is why:
Light is an awfully nasty form of energy in the chemical world. It does all sorts of crazy shit to molecules. Riboflavin (vitamin B2) is in beer and it is a photo-sensitizer. This means that when a photon of light of the right wavelength strikes it, the chemical is energized (activated) and can give its energy to another molecule. This activated B2 forces iso-alpha acids (from the hops) to undergo a homolytic cleavage forming a free radical, which reacts with the amino acid cysteine to form 3-methylbut-2-ene-1-thiol.
Ok, what the hell does all that shit mean?
Light puts energy into the chemicals in the beer, which leads to the formation of a thiol. And all you need to know about thiols is that they smell like skunk. Hence, the infamous skunky beer smell and taste. Sad day. Free radicals (like political or religious radicals) equal bad tasting beer.
Back to the container debate.
So, a keg lets practically no light through, which means the formation of this nasty thiol is slowed to a crawl. A can is basically a handheld keg. You can’t taste the metal, it is coated with a polymer (plastic lining) which prevents any metal actually making contact with your beer and the polymer does not degrade into the beer, leaving beer the way it is meant to be.
Now to bottles discussion. Amber bottles are that particular color because it is most effective in reflecting the particular wavelength that begins this cascade of beer flavor homicide. But the reality is that some light does get into the beer. Corona, in their brilliance, uses a clear bottle. I think it is fair to say that their beer degrades faster than any others, because pretty much all light is let into the bottle. They might counteract this problem with what is called a “free-radical scavenger”, which is a chemical that reacts quickly with the light-activated chemicals that lead to the skunk flavor. I don’t remember seeing free-radical scavengers as one of the four acceptable ingredients of beer.
Now, for a final thought on all of this: drink beer when it is fresh. It is easy to find fresh beer. The fresh beer is the stuff made by your local craft brewery or in the garage/basement/kitchen of people who are practice a tradition that goes back to the beginning of civilization. So, drink craft brews because they are going to be the highest quality, least photo-decayed beer that you can find.
And if you like it out of the bottle more than the can, I won’t judge you. Beer taste too good to fight over.
Until next time, enjoy that beer. If it tastes skunky, blame free radicals forming thiols in your beer.
Scrumps!
Mike Kratochvil
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Awesome entry. Now some quick side notes. No, I do not disagree with you on your discussion about cans. Surly Brewing which is extremely well known here in the Minneapolis area only offers their beer in cans. At $10+ for a 4 pack of 16oz cans, it better be damn good.
Well here's a Prost to my cousin for his help on this entry. Note the beer is Angry Hank's, a local tap room from Billings, MT where Mike grew up.
If you're interested in being a guest blogger on Brew It Yourself, feel free to contact me!
Prost!
-Ryan
Line of the day: "I don’t remember seeing free-radical scavengers as one of the four acceptable ingredients of beer."
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