So… I recently helped me friend out with some notes for this article. Most of what I told him went unused, but I did write it up, so I thought I would post it up here. It’s fairly rough, and poorly edited, but it won’t really matter because so is everything on this site.
Skunky: This is the flavor associated with Heineken, and comes from light exposure to the beer. The sun’s UV rays break down the hop chemicals in the beer to give it a skunky flavor. A good way to understand this flavor is to pour a good craft pilsner into 2 glasses, and leave one in direct sunlight for a few minutes, the difference is noticeable that quickly.
Oxidized: The oxygen in the bottle or can or keg will change the beer inside to give it a stale or old flavor, similar to licking a cardboard box. This is more likely to happen to beers that are older, but can happen to any beer, especially if it isn’t kept at a constant temperature. This also happens if the beer isn’t packaged properly at the brewery.
Green Apple: This flavor comes from a chemical called Acetaldehyde that occurs naturally during fermentation. Given proper conditioning time, Acetaldehyde will be consumed by the yeast. This is generally a sign that the beer was rushed to the market before it was ready. This has also been compared to cut grass and or latex paint and people will often refer to this beer as being “green”
Boozy: When you smell the beer before you drink it, and it smells like the cheap vodka your older cousin bought you when you were a freshman, this is what is referred to as “hot” beer. This problem usually happens when during fermentation. Beers that are “hot” are often beers that are higher in alcohol, and will benefit from aging for a year or more.
Buttery: If your beer has a problem that its taste makes you think it got a little bit of the butter solution from a movie theater, The beer has a problem with Diacetyl. This is a problem when the beer is removed from the yeast too quickly, or if there is a bacterial infection. A little bit is ok for some ales, but you shouldn’t be able to detect it in lagers, which is where it usually is a problem.
Vinegar: If you’ve ever opened a beer, and thought it would be better if it was used as a salad dressing then as a beverage, you know the problem if infected beer. Sometimes, this can be an intentional thing, when the beers are called “sour beers, but if there isn’t anything on the label about the beers being sour or wild, then there is a problem. This flavor comes from when wild bacteria find their way into the beer somehow, and they turn the sugars into acids instead of alcohol.
Creamed corn or cooked vegetables – You might have tried a beer once, and the taste reminds you of boiled cabbage, this is from Dimethyl Sulfides or DMS for short. DMS can come from either an infection in the brewery, or from lazy brewing practices, and is most likely to be found in pale lagers.
Baby vomit: Did he just say baby vomit, really? Yeah, I did. This smell in the beer comes from a chemical called Butyric Acid. Butyric acid comes from poor sanitation practices, and means either the brewery has a problem, or the bar that is pouring your beer has a problem. Either one can lead to a really nasty smell, that can make you feel like you don’t ever want to drink a beer again.
Gym Socks or stale cheese: This is from Isovaleric Acid. Isovaleric Acid is very similar to Butyric Acid, but it isn’t quite as putrid. Isovaleric Acid comes from the hops being used in beer. It is either from using hops that have gone bad, or using too many hops. Noticing this can lead you to either take back your beer and ask for another, or decide to spend more time in the boys locker room.