Ask Dan Carey about the growth in sour beers, the ubiquitous Belgian-style brews that until recently were an acquired taste for most American beer drinkers, and he smiles almost wanly.
“It’s mostly written about in the media by journalists that are intrigued with the style,” says Carey, co-founder, co-owner and brewmaster at the New Glarus Brewing Co. “It’s not a big part of our business, but it’s a fun part.”
Carey and I are sitting in the afternoon sun outside the Green County Brewery’s “Wild Fruit Cave” where he produces two different styles of Belgian-inspired sour beer. The cave isn’t a cave at all, but a separate building adjacent to the brewhouse of the original and now smaller of Carey’s two brewing facilities, the one devoted to his experimental beers.
Carey has been making sour, or Lambic, beers since the brewery first opened in 1993, and they have won multiple national and international awards over the years. They're a few of the many awards earned by Wisconsin’s third-largest brewer, best known for brands like “Spotted Cow” farmhouse ale and “Moon Man” pale ale.
The Wild Fruit Cave was first opened in 2014 and now the brewery produces about 10 sour beer batches annually totaling 3,000 to 4,000 barrels, a small drop of the 230,000 barrels overall that the brewery will produce this year. The cave also houses the wooden winery and distillery barrels and stainless steel tanks in which Carey’s sour and other beers are aged.
Some consider the term “sour beer,” with its images of skunky brews and spoiled stock, an unfortunate misnomer for what might better be termed as “tart” varieties. But veteran drinkers know that sour taste is the happy byproduct of a very deliberate Old World brewing process.
At one time, all beers were sour to a greater or lesser degree. The sterile facilities used in modern brewing keep beers protected from bacteria and other agents that can create sour flavors, but early brewers didn't have that luxury. They relied instead on the wild yeast strains that naturally exist in the environment and float through the air, and later on hops (used first as a preservative) to temper the influence of unwanted yeasts and bacteria.
Some modern brewers intentionally add bacteria to make their beers sour. They will inoculate their wort — the barley mash that eventually becomes beer — with species of Lactobacillus, Brettanomyces and Pediococcus, which produce the sweet-sour combination of flavors and funky barnyard aromas that characterize sour beers.
Others, including Carey, prefer to let nature take its course. He employs those traditional methods in producing his sour blonde ale and his red Flanders-style ale, both of which are used to form the bases of his many sour and fruit-based beers.
As we speak, Carey is in fact waiting for that process to conclude. Within the brewhouse, wort liberally laced with four garbage can-sized containers of hop cones is just finishing up its three-hour boil in a large copper kettle. Very shortly, the wort will be transferred through a series of pipes from the brewhouse to the cave for the next steps in the brewing process.
Once there, the wort will be strained and emptied into the koelschip, a large open top container also known as a “coolship” or, at New Glarus, the “cookie sheet.” The koelschip has a very large surface-to-mass ratio, which allows for efficient cooling of the wort, which today will equal 115 barrels of finished beer.
The room housing the koelschip has windows on three sides that can and will be opened to allow the night air to more efficiently cool the brew. It’s through these same open windows that wild yeast and bacteria strains will find their way into the wort and begin the spontaneous fermentation process. Wooden beams mounted in the ceiling of the room serve as a home for the bacteria and a base from which they can continuing feeding the fermentation cycle, Carey says.
There is no way to control the type of the bacteria that blows in through the windows, but there are seasons that are better for open-topped brewing than others. Spring planting and fall harvesting by local farmers both generate a lot more airborne “activity” from which the beer can only benefit, Carey says.
Once the beer is completed, it is casked and cellared for aging, where exposure to the wooden barrels and their own bacteria can complete the process. Eventually, the resulting beers will be tasted and blended, often with newer beers, for maximum aroma and flavor, providing the deeply complex brews that have come to characterize the sour beer category.
"There is a bright future for this type of beer, but the interest is just getting underway,” says Carey as we stand next to the “cookie sheet” and watch the wort cascading into the koelschip, sending up billowing clouds of steam.
The large room eventually fills with steam as we stand and alternately sip a samples of a previous batch of sour blonde ale, with its blend of sparkle, acidity and funky Brett characteristics, and his Oud Bruin, the red Flanders-style ale with complex flavors and balanced blend of sweet maltiness and tart vinegar.
The steam that flooded the room eventually cools, creating falling rain inside the fruit cave. But the unexpected shower does little to dampen our appreciation and the bright future of at least these two sour beers.
New Glarus Brewing Co. offers free self-guided tours daily of its Hilltop Brewery, 2400 Wis. Hwy 69 just south of New Glarus. Tours run Monday through Saturday from 10 a.m. to 5 p.m. and Sundays from 12 to 5 p.m. Behind-the-scenes “Hard Hat” tours commence at 1 p.m. on Fridays and include both the Hilltop and Riverside breweries. The cost is $30 per person, tours are limited to 15 people each and reservations are required. Dial 608-527-5850 for details.