Sour beer has always been a fascination of mine. So much so that my garage has been filled with pellicle ladened carboys for years all waiting to be blended in hopes of creating something magical. There are so many ways to create the final puckering elixir and the subtle nuances of the process leave endless possibility.
One of the interesting ways to make delicious sour beer is taking a regular beer brewed with traditional brewers yeast and introduce wild yeast and bacteria to slowly convert the unfermented sugars and other remaining compounds left behind by the traditional yeast to create a rainbow of interesting flavors and aromas. This can be done with almost any style; a stout, a wheat beer, a lager or a pilsner can be turned into something far more complex and interesting than where it started. Of course, that’s not to take anything away from delicious pilsners and lagers.
Cerebral Brewing and Our Mutual Friend Brewing—both from Denver—teamed up to make such a beer called Case Study. They filled second-use chardonnay barrels with a standard pilsner and let it rest for 11 months on a combination of house yeast and bacteria cultures from both breweries. Before bottling, yuzu and tangelo zest was added along with wild Colorado honey and left to bottle condition for an additional 11 months.
The beer pours a crystal clear and very pale yellow—2ish SRM—with a lively quarter inch of head that dissipates into a constant halo of tiny white bubbles and a steady stream of bubbles rising from the center of the glass. It is a pretty beer. My first whiff of the beer gives a light acetic note like a splash of vinegar along with white wine, crackery malts, and citrus. As it sits in the glass the white wine starts to come through more and more.
As I take my first few sips the beer is light and delicate with a low to medium acidity. It is very easy to drink but it does not lack character. The chardonnay comes through but not in an overpowering way and the light acidity matches well with the flavor profile. So many beers on the shelves these days are overpoweringly sour and they become hard to drink after a few ounces. This will not be an issue with Case Study. The base beer and the pilsner malt are still discernible and the carbonation cleans the palate leaving me wanting another sip. The citrus zest is a pleasant yet subtle touch but I get more of the yuzu than the tangelo. Tannins from the white wine grapes linger a bit after the sip and combined with the slight acid tingle they form a mellow enjoyable finish.