When Off Flavors are Spot On

The magazine I used to write for, All About Beer, officially died when owner Christopher Rice filed for bankruptcy earlier this year. To preserve some of the content I've contributed over the years, I'm reposting some of my favorite pieces here. Given my recent comments about the "story" of beer, our relationship to flavors shouldn't be any surprise. This article was published on the website June 30, 2015.


A couple of weeks ago, Jester King’s head brewer Garrett Crowell made an astonishing proclamation. The brewery has made a decision to switch to green bottles, not in spite of the danger it poses to beer, but because of it.

“My pursuit of the use of green bottles stems mostly from the character of all of my favorite beers. Cuvee de Jonquilles, Blaugies, Thiriez, Fantôme, Cantillon, Dupont all use green bottles. I’ve had brown bottle versions of some of these beers, and have had them on draft as well and there is an element missing from those versions that the green bottles have…. So many breweries have attempted to mimic the classic Saison Dupont yeast profile, and I feel what is most often missing is the light struck character that is integral to the profile of that beer.… I absolutely like skunky beer, oxidized beer, or “flawed” beer.”

Skunky flavor comes from a molecule called 3-methylbut-2-ene-1-thiol (3-MBT) that results when light interacts with compounds in hops. The process can be mitigated somewhat by the use of brown bottles, and entirely so by cans. But European breweries often insist on using green bottles, which offer very little protection. By the time those bottles make it over the sea to the U.S., the light-struck flavor is so prevalent that many, many people think it is one of the defining, intentional flavors of European beer—and Crowell is throwing in his lot with them. It is a defining feature, he’s saying, and those of you who turn up your snobby noses are missing something good. It’s a radical idea.

I’ve been trying to get my brain around this ever since, and while I’m still not convinced about the delights of skunked beer, I have to admit Crowell has a point. Hundreds of flavor elements appear in beer, some that come from ingredients, but many the result of processes. Among those that come from process, many are considered “off-flavors.” You may be familiar with some of the biggies—diacetyl, DMS, acetic acid. In most cases, though, an off-flavor is not exclusively bad; there are some cases where it is not only acceptable, but critical to the character of a particular beer type. Here, see what I mean:

  • Banana. This comes from the ester isoamyl acetate. It’s central to the profile of Bavarian weissbier, acceptable in some Belgian beers, but wrong in most everything else.

  • Barnyard. The florid flavors and aromas of Brettanomyces are so feared that the slightest hint can shut down a brewery. Of course, without Brett we’d have no lambic, Berliner weisse, or American wild ales.

  • Butter/butterscotch. This comes from diacetyl (a compound that also gives beer a slick coating on the tongue), and causes some people to gag. But it’s also appropriate in small doses in English ales and even some Czech pilsners—Pilsner Urquell has loads of the stuff.

  • Lactic/sour. One of the triumphs of the scientific age was getting control of the spoilage compounds that created sour beer. And, when you get a sour bock or bitter, that’s what it indicates. But in goses and Flanders tarts, it is absolutely critical.

  • Sherry. When beer oxidizes, it often turns stale; this is probably the number one enemy of most beer. However, in certain stronger, usually dark beers, age can confer a vinous, sherry-like note prized by cellaring aficionados.

Almost any flavor can seem “off” out of context. If you encounter roast in your kölsch, something’s wrong. Even in absolute terms, we may come to enjoy a flavor that once seemed objectionable: the biting bitterness of black coffee; the pungency of stinky cheese; the briny fishiness of roe or caviar. Most people don’t enjoy rauchbiers on their first swallow. But after a pint or three, once their palates adjust, many people fall in love with them. With familiarity, strong flavors can come to seem deeply pleasurable.

So Garrett Crowell may be onto something. Maybe we should all stop worrying and learn to love the skunk.

Jeff Alworth5 Comments