Get updates delivered to you daily. Free and customizable.
InsideHook
Beer’s Least Sexy Ingredient May Be Its Most Important
By Mike Dunphy,
4 days ago
Yeast plays an important role in the way your beer tastes. Getty Images
Dr. Frankenstein called forth lightning to bring his monster to life. Brewers call forth yeast. Perhaps more than any other ingredient, the unicellular fungus breathes life into a beer. It also plays a key role in determining the taste on your tongue. Unfortunately, it stays largely behind the scenes, ceding the spotlight — especially on beer labels — to the sexier hops and barley. But it’s the yeast that plays Merlin and makes the magic on your palate.
When we talk about beer or brewer’s yeast, we are really talking about two types — saccharomyces cerevisiae and saccharomyces pastorianus. The first is the OG, producing the ale family of beer, including witbiers, stouts, porters, saisons and IPAs. This top-fermenting yeast loves higher temperatures, ideal in a world without refrigeration, and makes a significant impact on the flavor and mouthfeel. They also work quickly, producing ale in in just three to five weeks compared to six to eight in lagers.
Whichever yeast goes into the wort — the sugary grain water drawn from the malt and hot water — the party ensues. The yeast plays Pac-Man on the sugar, and by doing so, produces the alcohol, carbonation and compounds that not only make the beer, but help determine the flavor. Here’s how.
How Yeast Impacts Flavor
A good way to think about yeast is like a key that opens a lock. When the yeast is “pitched” into the wort, the yeast ignites biotransformations that produce the beer and drive its flavor.
“There are two major categories with what yeast does with flavor,” explains Richard Preiss, founder of Escarpment Laboratories, a producer of yeast strains for brewers. “One is making its own flavors, and two is modifying or releasing flavors from other ingredients.”
As for its own flavors, yeast tends to bring the tastes we perceive as fruity, Preiss explains. That comes from ester compounds produced by the yeast. The boozy flavor also comes from the alcohol made by the yeast, as well as the carbonation. Spicy flavors tend to come through a meeting of yeast and malts. “That’s biotransformation of precursors from the malt you’ve got, something in the malt that’s normally flavorless that the yeast turns into that baking spice flavor,” explains Preiss.
In lager yeasts, the effect is less pronounced, leading to the cleaner, crisper flavor identified with them. A good way to think of it, Preiss explains, is in movie terms. On the ale spectrum, especially the Belgian side, “the yeast is the star of the show.” Lager yeast, on the other hand, is an assistant, “helping to highlight some of the flavors of the other ingredients.”
Meet the New Yeast, Same as the Old Yeast?
In the topsy-turvy world of craft beer, standing out from the rest is key. “Brewers are looking for differentiating factors, and yeast can be a way to do that,” Priess explains. Indeed, supplying brewers with the best yeast possible is the aim of Escarpment, as its work with Drekker Brewery in Fargo, North Dakota and Boxing Rock Brewery in Shelburne, Nova Scotia can attest.
This quest for unique yeasts has led other brewers to tap unusual sources, so-called “wild yeasts,” to craft a beer unlike any other. Many of these are in the natural environment. “You can find interesting yeast almost anywhere,” notes Priess, although, he adds, some environments more likely to have them — for example, fruit trees, which basically sweat sugar.
That led scientists in Patagonia to seek yeast strains in the bark of trees and create hybrids capable of producing unique flavors, with findings published in June 2024. Brewers also do their own field work. Austin, Texas-based Beerburg sources yeast from San Antonio’s Community Cultures Yeast Lab, which produces endemic yeasts swabbed from native Texas plants like ocotillo and Torrey yucca. First Magnitude Brewery in Gainesville, FL went so far as to collect yeast from live Frosted Elfin butterflies in Apalachicola National Forest to ferment a New England-style Session Pale Ale.
On the flip side, some breweries like Guinness don’t want to mess with a good thing. The present yeast used to make Guinness stout brewed in Dublin, Ireland, can be traced back to 1903 and occupies “a distinct group separate from other historical Irish brewing yeasts,” according to a 2024 report in the National Library of Medicine. Perhaps that’s really behind the slogan “Guinness is good for you.”
Get updates delivered to you daily. Free and customizable.
It’s essential to note our commitment to transparency:
Our Terms of Use acknowledge that our services may not always be error-free, and our Community Standards emphasize our discretion in enforcing policies. As a platform hosting over 100,000 pieces of content published daily, we cannot pre-vet content, but we strive to foster a dynamic environment for free expression and robust discourse through safety guardrails of human and AI moderation.
Comments / 0