This Is Why Your Beer Tastes Skunky

That smell. Ooooh, that smell. You know the one—musky and kinda sharp, it tickles the back of your nose and sets your head in motion looking for the source. On the street you're looking for who's just blazed up a jay; in the woods (or the 'burbs) you're on guard for one of those little black and white striped bastards. That skunk musk is a potent odor that humans are extremely sensitive to, and it's also a funk that's common in beer.

You've surely caught a whiff if you've ever sipped a Corona, Heineken, Tsing-Tao, Stella Artois, Rolling Rock, or any other beer that comes in a technicolored or clear bottle. It is such a prevalent character in these beers that many believe it's intentionally added by brewers. It's an astoundingly widespread myth, even finding it's way into a respected homebrewing manual from the early 90s like Charlie Papazian's The Complete Joy of Homebrewing (though later editions removed the erroneous claim). More recently, in Ashley Routson's The Beer Wench's Guide to Beer, the author says: "Heineken now purposefully exposes its wort to light during the brewing process, forcing it to become skunked prior to bottling."

Routson responded to me and said that it was "something that I learned from fellow brewers in the industry," and that "several brewers read my book before its release…and [reviewed] it for technical errors," so the idea that Heineken is intentionally letting light into their brewhouse is clearly common in the craft beer industry.

However, like so many urban legends, there is little truth to the claim.

Before we refute the claims of intentionally skunking, let's clear up the common confusions of what causes beer to pick up the offending aroma in the first place. There's only one way that a beer gets skunky: exposure to specific wavelengths of light.

It isn't caused by a cold beer getting warm and then chilled back down again. It isn't caused by age. It's the result of a chemical reaction between light and the bitter compounds in beer. I'll spare you the science behind lightstruck beer, but if you enjoy reading about organic chemistry, then you'll love this explanation. The important thing to understand is that light is the number one enemy to beer; it literally cleaves molecules in your delicious brew into pieces, creating a new compound that is nearly identical to one of the substances produced in a skunk's asshole.

Brown glass beer bottles block nearly all off the offending wavelengths of light, and cans and kegs, of course, block out all light. The trouble comes when beer is packaged in green glass—or worse still, clear glass. These bottles don't block the specific wavelengths of light that cause the reaction, and the reactions happen fast. Humans are so sensitive to the resulting compound that just a few parts per billion can cause you to wrinkle your nose.

A pint glass of beer in sun will get noticeably skunky in seconds.

Want to piss off a brewer? Accuse them of intentionally mimicking the anal secretions of a woodland mammal in their beer. Skunky odor is widely considered a flaw, as grievous as a glass of corked pinot, and flaws are anathema to brewers who obsesses over control, consistency and cleanliness.

So why is the skunk aroma so often detected in bottled Heineken? Blame the marketing department that, even after a packaging redesign in 2012, has stuck with the brand's signature green glass bottles. It's about branding. Those red star-adorned emerald green bottles are iconic, man. Put that beer in a brown bottle and the carefully controlled image of Heineken as "upscale" and "imported" goes down the drain. The brewers in Holland are just as obsessed with quality as any, and the Director of Quality at Heineken USA, Paul Van Der Aar, had this to say about the accusation that the brewers intentionally skunky their beer:

"For more than 150 years, Heineken has been brewing some of the world's most popular beers, using a mix of traditional brewing practices and new, modernized methods. We never purposefully expose our wort or beer to sunlight. In fact, throughout the entire production process, our brewing team has measures in place to protect our beers in green bottles from exposure to light."

You can confirm that the skunking happened in the bottle and not the brewhouse with a simple taste test. Sample a bottle of the European-style lager alongside one of the brand's canned brews. If the intentional exposure myth was true, you'd expect that both packages should have the same skunky character. What you'll find is that the bottled lager is rife with a skunk odor that threatens to overpower all the other flavors in the typically mild brew, while the the can is clean and crisp—free from even the faintest whiff of light-struck character.

Of course, not everyone shares the same sensitivity to skunky odors, nor does everyone think that they're abhorrent. Animal musk is an important element in designer fragrances, and there's something about that skunky tinge that can be kinda appealing in a weird way. And in the craft beer world—an industry built on the once contrarian idea that beer should be flavorful and full of character—there's one American brewery that's experimenting with intentionally skunky beer. Austin's Jester King is a farmhouse brewery known for complex sour beer and wild ales, and they've begun packaging some beer for sale in their tasting room in green glass bottles.

"I'm intrigued by what UV light can do to a beer," says Jester King's brewmaster Garrett Crowell. "It doesn't have to be a flaw, or an off flavor. It's simply another documentation of time and place."

Crowell wants to replicate the subtleties of the saisons and farmhouse beers of France and Belgium—beers that were traditionally bottled in green glass, as that is what the farmers had easy access to. These Old World brews often pick up notes that would be considered "off flavors" in other beers, but a not entirely out of place in the rustic farmhouse styles. The brewmaster also wants to make a statement on the state of the craft beer industry and America's developing beer culture.

"There are facets of popularity in beer culture that I feel are products of indoctrination," Crowell says via email. "[A brewer] can add a shit ton of hops to a beer and it's entirely polarizing and unbalanced, and then that becomes a beer that is praised for complexity. Or a beer can be ripping sour, requiring a box of Tums, and that beer is also praised. But if there is any indication of slight deviations such as oxidation, diacetyl, skunkiness etc, that beer suddenly becomes "flawed" and inappropriate. That is something that I don't quite get."

The Beer Wench touches on that idea in her book as well, saying "US-based Heineken consumers became accustomed to its 'unique' skunk flavor—so much so that lightstruck flavor became an attribute of the beer, rather than a flaw."

Flaws and off-flavors are in the eye of the beholder—or on the tongue of the drinker in this case. While beer judges, known as cicerones, and a brewery's quality control professionals will recoil at the first whiff of that skunk smell, don't let them tell you what to like. Maybe a skunked Heineken reminds you of your halcyon college days. Maybe a lime-spiked Corona instantly transports you to some private beach of the mind.

Taste is subjective, and that's really what Jester King's experimentation—and Heineken's business plan—with green bottles is about, as Crowell explains:

"The intent for green bottles is to show that it's OK to like things that other people tell you you aren't supposed to like. Simple as that."