An IPA is typically categorized as an East Coast-style beer that features a hazy body with tropical and citrus aromas and flavors, or a West Coast-style beer that is more malt-forward with prominent piney and earthy characteristics.
Even though the majority of IPAs fall into one of these two categories, this can’t be said of the newly crafted Brut IPA, which features a crystal-clear, light body and flavor that’s as dry as the desert air.
“Brut” is a French word meaning “raw, rough, or very dry.” This term is applied to very dry champagnes and sparkling wines that are categorized as brut, extra brut, or natural brut. These champagnes and wines contain less residual sugar. During fermentation, an enzyme called “amyloglucosidase” helps yeast feed on the sugars and break them down, which results in a drier-style wine. This same enzyme is used in higher alcohol beers like imperial stouts and IPAs because the yeast consumes more of the sugars during fermentation, which results in beers with a higher ABV that aren’t syrupy, thick, and sweet.
Brewers seek to get the residual sugars, which are measured in degrees Plato, to the desired point within each style. With this enzyme, brewers are able to lower the degrees Plato to meet the needs of imperial styles. When this same enzyme is added to an already dry beer style, the gravity—aka the sugars that will be converted to alcohol during fermentation—becomes lower and the beer becomes drier. That is how the Brut IPA came into being.
The mastermind behind this intriguing style is brewer Kim Sturdavant at the Social Kitchen & Brewery in San Francisco. Curiosity led him to play around with amyloglucosidase with a traditional American IPA to see what would come from it. He knew that it would lower the gravity and produce a drier-style IPA, and the result from his experimentation was the first-ever Brut IPA.
According to the Brewers Association Beer Style Guidelines, a traditional American IPA should have a final gravity in degrees Plato somewhere between 2.5 to 4.1, compared to its original gravity of 14.7 to 17.1 degrees Plato. What happened with Sturdavant’s experiment is that the enzymes brought the finished gravity to a flat line of 0 degrees Plato, making it “spritzy, really light-colored, all-fruity hops, and super crisp.”
This super light-bodied ale is counter to what a traditional American IPA should be—a medium to low-medium body—according to the Brewers Association Guidelines. To better shed light on the tantalizing style, it helps to look at what the enzymes accomplish with an imperial IPA’s finished gravity compared to its original. The original gravity is around 17.1 to 23.7 degrees Plato and finishes off at 3.1 to 5.1. This drastic drop in gravity is what helps the imperial IPA not finish off too sweet or thick, as the enzyme helps the yeast eat away at the excess sugar.
More breweries across the nation have been catching onto the style by brewing their own versions, like Rahr & Sons Brewing Company out of Fort Worth, Texas. “The owner had a few around the country and was really into them, and wanted us to make one for the anniversary party last year,” says Rahr & Sons head brewer Austin Heisch. “So [I] made one up and he really enjoyed it, as well as all the customers that came in and tried it themselves.”
When it comes to understanding the technicality behind the brewing process of a Brut IPA, Heisch explains how much they can differ—not only in their flavor profiles, but in their final gravity as well. “Our final gravity went into the negatives, which made it super dry, light, and crisp,” he says. “Most of our beers finish around 2.5 Plato for the final gravity, so this was definitely an interesting endeavor for us.”
As far as when to put the enzyme in during the brewing process, it varies with little effect on the finished product itself. “You can do it in a lot of different places, with a lot of people throwing it in the mash tun,” Heisch says. “We’ve personally done it in the fermenter, which so far has given us great results with no issues arising.” The Brut IPA continues to intrigue consumers while providing brewers with a new opportunity for experimentation. What that could lead to is up for speculation, with an exciting future for the brewing culture.