Bitterness

The Bitterness Problem (Beer and Brewing)

This is interesting, too: According to a recent Hopsteiner study, the solubility of some otherwise hydrophobic bittering compounds appears to increase with higher ABV, suggesting a more intense (or efficient) bitterness may be possible in higher-strength beers.

De Baets at de la Senne watches both the alpha- and beta-acid content, as he packs a substantial amount of bitterness into highly drinkable beers, from svelte Taras Boulba (4.5 percent ABV, 50 IBUs) up to the Brusseleir dark IPA (8 percent ABV, 70 IBUs). He’s also an advocate for hop quality and prefers German varieties.

“You want a fine bitterness in your beer,” he says. “To achieve that, you really need good hops. Some high-alpha varieties are fine, but their bitterness can be harsh at times. I will always prefer an early crop for those, as when they stay too long on the plant, their alphas are higher, but there is a risk of getting a harsh, unpleasant, and unrefined bitterness from them. A good relationship with a skillful grower helps a lot here. Of course, I like the European varieties a lot, and I think you get the finest bitterness with the so-called dual hops, like German Perle for instance.”

De Baets says that you can get a very refined bitterness from low-alpha Noble hops—but use too much, and you risk getting vegetal notes from all the hop matter. So, there is another balancing act. He also recommends controlling pH, targeting 5.2 during the boil.

Above, I mentioned how calculated IBUs don’t account for humulinones and polyphenols. Several recent studies, chiefly from Oregon State University, have found that those compounds—and not only iso-alpha acids—are responsible for some of the bitterness in beer, especially in dry-hopped beers. Iso-alpha acids remain the most important predictor of bitterness, but when IPA brewers eschew kettle hops for substantial whirlpool and dry-hop charges, it makes sense that these other compounds would become more important.

There are ways to get that unpleasantly bitter stuff out of solution while preserving that beautiful aroma. Cold and time are part of the solution; coarse filtering is another option, as is centrifuging, which can pull out some of the more volatile, unpleasant hop compounds while leaving more desirable ones, such as linalool and other aromatic terpenes.

At Sapwood Cellars in Columbia, Maryland, they don’t have a centrifuge; they rely on Biofine after dry hopping. Cofounder Scott Janish—also the author of The New IPA—finds that their hazies are still hazy. “This is not to clear it up—it doesn’t clear it up,” he says. “This is more trying to speed up the time a beer peaks.”

They typically add the Biofine a few days before packaging. “For us it seems to help a little bit in terms of the smoothness of a beer, peaking a little sooner, and just making a more drinkable beer—because that’s really what we’re after.”