Brut IPA’s (pronounced, broot, eye-pee-aye’s) sure are hot right now. You’ve probably noticed them popping up at craft breweries or in the craft beer section of your local liquor store. And maybe you’ve wondered: WTF is that?

Well, we wondered too. So, we decided to do a little research for the good of the common-uninformed-beer-drinker, to find out what exactly makes a Brut IPA and why they’re different. And we fell down a rabbit hole in the process; a vortex full of information, history, background, chemistry and words like amyloglucosidase.

Which, is really the nut of the Brut IPA. That enzyme, amyloglucosidase, is one that’s commonly used in champagne fermentation to reduce the sweetness of the bubbly. Similarly, it has been used regularly by brewers to make big boozy beers (like imperial stouts and double/triple IPA’s) less sweet. Essentially, amyloglucosidase eats up complex sugars that wouldn’t otherwise ferment. It gives the brewer’s yeast an extra meal to feast upon, reducing sugars and reducing the sweetness of whatever it is you’re fermenting.

But, it wasn’t until mid-2018 that some crafty brewer, got the bright idea to use this special enzyme in a regular American IPA recipe.

Kim Sturdavant, the Brewmaster at Social Kitchen & Brewery in San Francisco, had no idea he was about to birth a new style of IPA when he did this. It was just an experiment, a thought that had been floating around in the back of his head for a while. So, when he had a little extra time on his hands, Sturdavant started playing around with amyloglucosidase in his IPA recipe.

The results blew him away.

“I took a growler home and realized that I finished the whole thing,” Sturdavant told Craft Beer & Brewing. It was bone-dry, slightly hazy and yet still bright, super crisp, light and very aromatic. “It’s just unlike anything else I’ve had.”

He named it the Extra Dry Brut IPA (later shortened to Brut IPA) and thus was born the latest trend in craft brewing. Breweries from Maryland to Michigan, Colorado to California are now, all experimenting with their own versions of this new beer style, adding different ingredients at different times in the brewing process, testing when is best to add the amyloglucosidase, what hops are best to use and messing around with everything else in the grain bill.

Sturdavant’s current recipe includes 20 percent corn, 20 percent rice and the remainder is Pilsner malt.

“From the flaked rice, we got a coconut flavor, from the corn, added creaminess,” he said. “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.”

So, if you’re into dry IPA’s that don’t bend too far over the fruity, hoppy or bitterness scale, then the brut IPA might be your beer. And given the sudden popularity of this style, it shouldn’t be too hard to find one somewhere in your local craft beer scene.

If you happen to live in Colorado, 4 Noses, Wiley Roots, WeldWerks, and Fermaentra all brew some tasty bruts — each one a little bit different from the next.