Some craft beer labels are works of art. Others read like scientific formulas. At the store, on bar menus, and online, acronyms like SRM are moving from the province of the professional and the homebrewer to the everyday beer enthusiast. "These numbers can be meaningless gibberish until you calibrate yourself to what they mean," says Randy Mosher, author of Tasting Beer.
Here's what those frequently seen acronyms stand for, and how decoding them can help you be a happier beer drinker.
ABV: Alcohol By Volume
Unlike hard liquor, beers aren't measured by proof, but most commonly by ABV— alcohol by volume. This number simply lets you know what percentage of your beer is alcohol.
Brewers take samples of beer as it ferments to see how much sugar the yeast is converting into alcohol, and tweak the batch to get to the final level of booziness they're looking for. The method of measuring ABV isn't going to come up in everyday conversation, but the number itself is pretty crucial to figuring out what you're going to drink and how much of it: a 4% Berliner Weisse isn't going to give you the spins as quickly as a 10% imperial stout.
IBU: International Bitterness Units
International Bitterness Units measure hop bitterness on a scale from 0 to 100. Though extra-hopped IPAs can reach into the 70s, Mosher notes that the bitterness you perceive as a drinker depends on the balance between hops and malts in the finished product. "A big, rich beer with malty flavors can still have 50 BU," he says. And though both German weissbiers and pilsners have a similar ABV and SRM (see below), the crisp bitterness of the pilsner will shine through more distinctively.
SRM: Standard Reference Method
Possibly the most confusing designation, Standard Reference Method measures the color of the beer in your glass—the higher the number, the darker the beer. But color does not necessarily equal flavor. While it's easy to make overarching judgments and think that pale gold beers are light in flavor, amber beers are sweet and malty, and near-black beers are super roasty, exceptions abound—like black kölsch!
"SRM is a really useful number from a brewer's point of view because we need fine control over those kind of things," Mosher says, but for the average beer drinker, it's not as essential. However, it might be fun for a blind taste test: pick a barleywine, an Irish red ale, and a Vienna lager, all of which have the same SRM range, and see who can tell what's what.