The enzyme amyloglucosidase has been used in brewing for a while now. It has the ability to break down complex sugars that might not otherwise ferment, allowing the yeast a bonus meal during fermentation. As such, it has been popular with big, boozy imperial stouts so that they aren’t supersweet on the palate.
In San Francisco, at Social Kitchen & Brewery, Kim Sturdavant, the brewmaster, had been using amyloglucosidase on his triple IPA to help tamp down the sugars found in that beer. “I’ve been using it for two or three years but had it in the back of my mind to use it on a traditional IPA, to make it bone dry, a recipe with no residual sugar.”
When his brewhouse schedule allowed last November, he gave it a go. He brewed a traditional IPA and added the amyloglucosidase after the first round of fermentation. The result was a 0° Plato, bone-dry, super- aromatic, slightly hazy but still bright, IPA.
“I took a growler home and realized that I finished the whole thing. It’s just unlike anything else I’ve had,” he says. At first, he considered calling it Champagne IPA (the folks in that region of France would likely have something to say about it) but, after consulting with a wine-minded friend, settled on Extra Brut IPA, eventually shortened to Brut IPA.
Within days, the city’s beer scene was buzzing about this new kind of IPA, and brewers near and far were adding it to their lineups. Drake’s Brewing Company (San Leandro, California) has been blogging about their experience brewing the style, and from Colorado to Pennsylvania, brewers are trying their hand, figuring out the best way to make this IPA.
Since the style is still in its infancy, there’s a lot of crawling going on before it breaks into a full run, and brewers say they are experimenting with when to use the enzyme, the types of hops to use, and a diverse grain bill.
“We’re using a lot of adjuncts in the grist, a lot of wheat and rice, because they are fermentable with no sugar,” says Josh Grenz of Verboten Brewing & Barrel Project in Loveland, Colorado. “All the hops come after the boil, and what we’re getting is very aromatic without the bitterness.”
Using the enzyme, he says, adds about two days of fermentation because when it’s added, the yeast ramps back up. Otherwise it’s a pretty normal IPA schedule.
Credited as the creator of the style, Sturdavant says he feels a responsibility and “pressure” to make the best Brut IPA out there, so that means experimenting from batch to batch. In June, he brewed a recipe that had 20 percent rice, 20 percent corn, and the rest Pilsner malt. “From the flaked rice, we got a coconut flavor, from the corn, added creaminess,” he says.
“We’re not doing it because it’s cheaper—it’s not. We’re doing it for the light color. I like these beers to be lighter than a Pilsner—not [colorless], but certainly very light.”
His style allows for some haze but nothing comparable to a New England–style version. Adding hops after the boil gives all of the aroma with little to no bitterness, something many drinkers are currently accustomed to. Sturdavant has found that the style is also best for IPA recipes that are no higher than 7.5 percent ABV.
At first, he was adding the enzyme late in the fermentation process but recently has begun adding it during the mash. It still breaks down the extra sugars but doesn’t leave the finished beer at complete 0° Plato. Still, he has his reasons.
“With every batch of beer, we re-harvest yeast, and so if you use the enzyme, it’ll will carry over when you re-pitch, and that’s not something we want necessarily.”
Regardless, using amyloglucosidase isn’t something to be taken lightly. Sturdavant and others warn that knowing yeast and understanding yeast nutrition is paramount.
“It creates different problems, so it’s important to understand yeast and yeast nutrition throughout the process,” he says.
Drake’s has already ramped up the creativity, adding blood-orange juice to one batch for a mimosa effect, and is thinking ahead to packaging.
“Many questions remain unanswered before we put this new beer style in a bottle,” the brewery says. “How much bitterness can such a light-bodied beer support? What direction should we go for hops flavor? How much does malt matter in a beer that is so aggressively fermented down? Whatever we decide, as hopheads, we’re stoked. The Brut IPA style lets the hops shine in a wholly unique way, and it’s an excellent counterpoint to the juicy New England–style IPAs we’ve been making.”
It’s interesting to watch the beginning of what could become a recognized style. Drinkers who have tasted well-made batches are quick to rave about it, leading to additional excitement. At the recent Craft Brewers Conference in Nashville, Tennessee, brewing legend Pete Slosberg, of Pete’s Brewing Company, asked if I had tried any of Sturdavant’s Brut IPAs, noting that he had just finished a conversation with a Polish brewer who was making them at his pub.
Whether Brut IPAs will become as widely sought-after as the New England style remains to be seen. Or there’s the possibility that it could become a niche found occasionally like the Black IPA (or Cascadian Dark if you’re into calling it that). What we do know is that right now, there’s genuine excitement on the part of brewers, and that leads to only good things for drinkers.
For now, most brewers agree that the more tropical New World hops are best represented in the style, not only because it’s what’s popular but because the aromas and flavors best complement the bone-dry nature of the Brut IPA. Still, Sturdavant says he’ll continue to experiment with each new batch.
“Call me in a year, and I might be all about the pine.”
This article first appeared in Craft Beer & Brewing Magazine.