Pic(k) of the Week: Uber Pils, illuminated

A glass of draught Small Craft Warning Uber Pils —from the Heavy Seas Brewing Company of Baltimore, Maryland— is back-lit by the late afternoon summer sun at ...

Rustico Restaurant
Alexandria, Virginia.
25 June 2013.

Here's how the brewery describes its beer:

Small Craft exemplifies a robust pilsner—crisp, well-carbonated, and slightly sweet. The beer is characterized by a firm malt backbone and a pronounced hop character from an array of hops.

ABV: 7%
IBUs: 35
Hops: Warrior, Palisade, French Strisselspalt, Saaz, Simcoe, Cascade
Malts: 2-row, Munich, Caramalt

The effect of the light on the beer was so striking, that I ignored the other not-so-good effect of that sunlight on my beer. You shouldn't.

Certain compounds in hops are light-sensitive, and when exposed to strong light, a photo-oxidation reaction takes place, creating the intensely flavor-active compound 3-methyl-2-butene-1-thiol. MBT is one of the most powerful flavor substances known to man. Commonly referred to as "skunky," the pungent odor compound resembles that of the famously malodorous defense spray deployed by skunks.
— Oxford Companion to Beer

Beware: this reaction occurs both in sunlight AND florescent light, and it happens very, very quickly.

Green or clear glass offers little to no protection against this reaction, but brown glass is highly effective, at least against short-term or low-intensity exposure. Aluminum cans or beer stored in kegs offers the best protection against exposure to light.

The term 'skunking' is often applied cavalierly to any beer gone off. To be precise, skunky smells like, well, skunk, and is caused from exposure, not to warmth, but to sunlight, as explained above. On the other hand, the off-flavor and aroma of a beer that has staled —such as one exposed to very warm temperatures (in the trunk of a car in the summer) or one just kept sitting around for a long time— can be described as "cardboardy". Two VERY different, but bad, effects.

The moral of the story is to be good to your beer and it will be good to you —except, maybe, when it's the star of your camera shot.

********************

• Caveat lector: As a representative for Select Wines, Inc. —a wine and beer wholesaler in northern Virginia— I sell the beers of Heavy Seas.
• Pic(k) of the Week: one in a weekly series of personal photos, often posted on Saturdays, and often, but not always, with a good fermentable as a subject. Camera: Olympus Pen E-PL1. Commercial reproduction requires explicit permission, as per Creative Commons.