Saturday, October 20, 2012

Sour beer: Open wide and embrace the bacteria

June 1, 2012

There are tons of ways to make sour beer, but they all start with bacteria. This might seem counterintuitive to homebrewers who live by the code of sterilize, sanitize, clean and repeat when it comes to brewing beer. Most times, bacteria are the enemy and must be vanquished before they ruin an entire batch of what would have been tasty stuff. Not so with sours.

Andy "Hollywood" Parker, brewer and barrel herder, extols
the virtues of sour beers in the Avery barrel room in Boulder.
“A brewer is basically a janitor 75 percent of the time,” said Andy “Hollywood” Parker, senior brewer and barrel herder for Avery Brewing Co. “With barrel-aged beers, you throw most of that out the window.”

The bacteria produce the lactic or acetic acids that create the unmistakable flavors found in sour beers. The microorganisms are trapped in oak barrels with the beer and work for six months or a year or three or more to do their job, thriving on the trace amounts of oxygen that seep through the slightly porous wood into the barrel. Lactic acid has almost no smell and creates a tingling, sour sensation along the sides of your tongue. The funky, rustic aroma of some beers comes from acetic acid, Hollywood said, which has a vinegary flavor that’s a great component in small amounts.

But how do you channel the bacteria that make great beer? These microbes are floating around us everywhere right now. How do you isolate them? Do you even want to isolate them? A lot of Belgian sours are spontaneously fermented.

“They leave (the beer) out in a big swimming pool, whatever’s in that valley floats in, and they put that work into oak barrels and let it roll for years and years,” Hollywood said. “There are still a few traditional breweries in Belgium that are doing it that way. But it’s a lucky thing; it depends on what’s there.”

One valley could have a population of yeast and bacteria that make great beer, and the next valley over could be a dud. Rather than waiting for the building blocks to fall out of the air, many brewers have harnessed specific strains that they know create predictably palatable beer. Hollywood found his favorite strain of acid-producing bacteria in a barrel and has been propagating it from barrel to barrel to create sours for Avery. What was one barrel became 150, and he continues to play around with other strains from labs to get more variety. Each strain of bacteria creates a totally different flavor profile — even a single strain can be the catalyst for a wide range of brews.

Because sours are so labor intensive — tasting, barrel aging, more tasting, blending, another round of tasting — they are a little harder to come by. That’s what makes Avery’s Sour Fest on Saturday, June 2, special. Hollywood said the 400 available tickets were snatched up in a matter of minutes. If you were one of the lucky ones to procure your golden ticket, look forward to sampling around 60 sours from Crabtree, Crooked Stave, Deschutes, Dry Dock, Funkwerks, Great Divide, Mountain Sun, Odell and The Lost Abbey, among others.

From the Fridge: Avery’s Eremita III

Sour Fest may be sold out, but you can still dig up some great sour beers at local breweries and liquor stores. This week’s installment comes from Avery Brewing Co.’s fridge, not mine, but Eremita III is an enchanting, acidic enigma and worth a closer look. As its name indicates, this is the third beer in the Eremita series of sours.

The series is exclusive to the Avery Tap Room in Boulder, as Hollywood wanted to put all of his time and creativity into the beer instead of squandering it on label approval or bottling or trucking it around to festivals. Eremita I was really easy drinking, he said, and Eremita II was a blonde sauced with loads of peaches and apricots, giving it an incredibly fruity profile.

Eremita III comes from the same microbial stock as its predecessors, but it’s an animal all its own. This brew is a blend of five different beers from 12 different barrels. Hollywood spent months with a blind tasting panel and started with a bank of about 30 oak barrels to come up with this rich, dark beer that has an earthy, sour aroma from just the right amount of acetic acid.

“After about 20 to 30 blends, we narrowed it down to those 12 barrels, and each of those barrels added something to that complex blend,” Hollywood said. “It’s not like hey, we put some beer in a barrel. It takes a lot of work. And by work I mean sitting around and tasting beer. We’re not sitting around drinking beer; we’re tasting beer — we’ll plan our day around not having coffee beforehand or eating beforehand.”

And when this big, tongue-tingling beer is gone, it’s gone.

“I’m not even interested in trying (to replicate any of the Eremita beers),” Hollywood said. “I probably can’t reproduce Eremita. Is it possible? Maybe, but that’s not as interesting to me as creating something new and different.”

Krista Driscoll
Hophead

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