Friday, March 27, 2009

Rotten Asparagus Ale

In brainstorming how I should best run the near-beer tasting last week, I asked reputed foodie George for suggestions. In response, he forwarded me a score sheet used by the American Homebrewers Association that detailed the scale of its rating system and by which criteria judges evaluate beer. Even better, the sheet included a list of “descriptor definitions” that opened my eyes to how many ways you can say “tastes like beer.”

The list reads as follows:
  • acetaldehyde — green apple-like aroma and flavor.
  • alcoholic — the aroma, flavor, and warming effect of ethanol and higher alcohols; sometimes described as “hot.”
  • Astringent — puckering, lingering harshness and/or dryness in the finish/aftertaste; harsh graininess; huskiness.
  • diacetyl — artificial butter, butterscotch, or toffee aroma and flavor; sometimes perceived as a slickness on the tongue.
  • DMS (dimethyl sulfide) — at low levels a sweet, cooked or canned corn-like aroma and flavor.
  • estery — aroma and/or flavor of any ester (fruits, fruit flavorings, or roses).
  • grassy — Aroma/flavor of fresh-cut grass or green leaves.
  • light-struck — similar to the aroma of a skunk.
  • metallic — tinny, coiny, copper, iron, or blood-like flavor.
  • musty — stale, musty, or moldy aromas/flavors.
  • oxidized — any one or combination of winy/vinous, cardboard, papery, or sherry-like aromas and flavors.
  • phenolic — spicy (clove, pepper), smoky, plastic, plastic adhesive strip, and/or medicinal (chlorophenolic).
  • solvent — aromas and flavors of higher alcohols (fusel alcohols); similar to acetone or lacquer thinner aromas.
  • sour/acidic — tartness in aroma and flavor; can be sharp and clean (lactic acid), or vinegar-like (acetic acid).
  • sulfur — the aroma of rotten eggs or burning matches.
  • vegetal — cooked, canned, or rotten vegetable aroma and flavor (cabbage, onion, celery, asparagus, etc.)
  • yeasty — a bready, sulfury or yeast-like aroma or flavor.
A pretty cool vocabulary lesson, really. Some, like grassy and yeasty are pretty obvious, but others, like estery, seem to be words only used in descriptions of brewed beverages. (No, Google, I don’t mean estuary.) Now I’m have to wonder whether beer that smacks of canned corn or cardboard or plastic adhesive strips would necessarily be bad or if it such flavors could actually exist in a good-tasting product. Thinking back to the comment cards that I had my near-beer tasters fill out, I can see where some of this vocabulary would have been appropriate. They called certain brews out for tasting sulphurous or metallic. Would tasting like tomato paste mean a beer tastes estery or vegetal?

I was most curious, however, about where the term light-struck came from, since it sounds like it should mean something more pleasant than what it does. The term, it turns out, is quite literal. Beer takes on a skunky flavor when after being exposed to ultraviolet or visible light, or so says Wikipedia. Light causes riboflavin to react with hops-derived isohumulones to create a flavor that is chemically similar to a skunk’s spray. Incidentally, Miller High Life lacks isohumulones and therefore apparently cannot get skunky. Furthermore, the purpose of the brown beer bottles is to keep out any isohumulones-affecting light. Green and clear bottles offer the beer inside no such protection.

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