Robin Shepard
Refresher Course, the newest wild yeast-fermented beer in the O’so lineup, was one of a handful of beers that stood out for me during August 13’s Great Taste of the Midwest. It just started turning up in local stores in 750 mL bottles.
What is it? Refresher Course from O’so Brewing of Plover.
Style: Refresher Course is a blonde ale fermented with Brettanomyces. So-called blonde ales are really a range of light-bodied, light-colored ales – clear golden to straw color. The style is crisp, with a light to medium body. Expect low hop bitterness with light maltiness. Overall, blonde ales are balanced and clean at 4% to 5.5% ABV. Refresher Course is distinguished by the wild yeast that lends sour and tartness.
Background: Sours continue to grow in popularity, appealing to those who enjoy yeasty, musty, earthy, tart and sour combinations. These beers seem to provoke whimsy and creativity in brewers, but creating one also means turning to science. Among the biggest challenges in the brew house (beyond letting the bugs of wild yeast and bacteria go free to infect other beers) is replicating sour flavors consistently. Refresher Course is 100 % Brett-fermented; no cultivated brewer’s yeast is used. “You really don’t know what you’re going to get with a Brett beer until it’s done,” says O’so brewmaster Marc Buttera. “Wild yeast can do something different every time.”
To address this, Buttera turned to a master’s thesis written by Chad Yakobson, who also owns the Crooked Stave Artisan Beer Project, a Denver brewery that specializes in sour beers. Yakobson’s graduate studies at Heriot-Watt University in Edinburgh, Scotland focused on isolating yeast species. This has made him one of the foremost authorities in using Brettanomyces to make beer. Buttera was so excited about what he and his O’so brewers learned from Yakobson’s work that he named the beer “Refresher Course” in his honor. The beer’s label was designed with the look of a chalkboard; it even lists the website for Yakobson’s thesis.
O’so is becoming well known for its sour beers. Buttera has even reconfigured his portfolio, downplaying his other bourbon barrel-aged products to allow more time to work with wild yeasts and bacteria. The O’so line now includes Refresher Course and Winds of Change (a Brett-IPA) as year-round beers in large bottles. Last December, O’so started making Infectious Groove (a kettle-sour Berliner Weisse) as a year-round six-pack offering.
Over the past year Refresher Course has been offered a few times in the brewery’s Plover taproom and turned up on a limited number of draught accounts locally. Now, the beer is bottled-conditioned in cork-and-caged 750 mL bottles that sell for $9-$10. Refresher Course finishes around 5% ABV.
Tasting notes:
Aroma: Light citrus hints of melon, pineapple and lemon.
Appearance: Hazy, yellow-golden color with a thick, soft, white head.
Texture: Light- to medium-bodied, bubbly, with some softness.
Taste: A soft musty funkiness in the beginning; however, it’s the sweet fruity accents of lemon that enliven the tart side of this sour. It’s not overly tart, just enough to seem crisp and refreshing.
Finish/Aftertaste: Dry, with mild tartness.
Glassware: I prefer the goblet or large chalice for this beer to show off its bright color. The light citrus aroma of lemon and melon will be more apparent under the nose.
Pairs well with: Sandwiches, and lighter meats and seafood on the grill. Mild musty cheeses go well, too.
The Verdict: Refresher Course is a light, effervescent sour. Notes of lemon, pineapple and melon give it a bright and crisp character, while there’s enough malt to lend pleasant softness to the mouthfeel. New Zealand “Dr. Rudi” hops offer a faint resiny pine flavor, adding subtle dryness in the finish. Hardcore sour fans may find it too tame, but I enjoy it for being a clean, mildly tart, fruity sour that should appeal to a range of drinkers.
