Ripe fruit has quite a community of yeast and bacteria on the skin, and therefore, it’s ideal for fermenting your next fruit beer, be it a standard recipe, a lambic style, or something you’ve been saving for that barrel in your homebrewing kit, says Jeff Melo of Nashville’s Bootleg Biology, a yeast lab.
Lambic is a natural thought, but for folks trying to use fresh fruit for the first time or for those who want to see what flavors and nuance the produce produces, Melo suggests gravitating toward a Pilsner or a wheat-malt base because it “gets out of the way and lets the fruit be really expressive.” When you look at lambic producers, they want a certain beer profile that will show off, not cover up, the fruit. The same is true with many of the commercial examples of fruited beers on the market today. When thinking about the fruits to use, try to match color with color, as best as possible. Cherries work well with darker-malt base beers. Peach and apricot complement a lighter malt bill.
What you see commercially will work for homebrewing. Look for fruits with delicate skins—blueberry, raspberry, and blackberries—and macerate them before adding them to the beer. Squishing and getting the skins broken are key so that the yeast on the outside can get in contact with the sugars on the inside.
Finding the right fruits to use is as simple as going to the yard or by the roadside, but it’s important to know the source and to make sure there aren’t residual pesticides on the skin. Because of that, it’s usually best to avoid fruit from farmer’s markets unless you can ascertain from the farmer that no pesticides were used.
Doing a safe fermentation and putting the beer in an anaerobic environment in a carboy with an airlock to make sure CO2 is produced can help eliminate bad bugs, says Melo. Because we’re picking fruits, there’s an assumption—at least by many first-time brewers—that the end result will be a wild beer. Not so, says Melo.
“Homebrewers are surprised when they get a clean-tasting beer with wild fruits,” he says. “Saccharomyces cerevisiae is the number-one wild yeast in our local yeast project cultures. It’s on flowers and whatnot, and it’s adept at working with simple sugars so it takes over quickly, resulting in a clean-tasting, 100 percent wild fermentation.”
“Everyone who came up in the beer world heard the stories of lambic fermentation and the story behind how those are made. More and more, as scientific evidence becomes available, it’s becoming clear that Brettanomyces is rare in nature, so it’s something that these historic breweries have cultivated and curated. So, it’s why you find Brett in lambic breweries, as opposed to the first time you might try [brewing] a fruity beer.”
“The yeast, for me, is the star of the show. When you’ve made a dozen different beers or beer styles with a product that is agriculture-focused, wild yeast can be expressive, and you have beautiful layers, thanks to the microbes.”