Progress is messy. When an innovation makes something clearly better—as the adoption of hops did with beer—we tend to lose other things of value.
That may be the case with yarrow as a brewing ingredient.
When we venture past hops and grains to look for other safe plants to chuck into our kettles and tanks, the realm of unorthodox options is vast. Beets, dandelions, garlic, jackfruit, monk fruit, sassafras, sweet potato, and tomatoes are just a handful of the possibilities we’ve analyzed here at Special Ingredient Laboratories.
Yet there are other botanicals that only seem odd because we no longer bring them into the brewhouse. In the European tradition, at least, our beloved hops replaced those other ingredients long ago. Bog myrtle, heather, and rosemary are among those additives that were once typical in ales. So is yarrow. All four of those were among the typical ingredients in gruit—those mixes of herbs that once flavored the ales of the Low Countries.
Why yarrow? Well, one of the really nice things about it is that it’s easy to find—as foraging goes, we’re talking a low level of difficulty here. It doesn’t just grow like a weed, it is a weed, popping up here and there throughout the meadows, hillsides, and roadsides of the world’s temperate zones. If you think you’re not familiar with yarrow, it might only be because you didn’t know its name. Once you see its picture, though, you might realize that you’ve been seeing its small white flowers here and there all your life. It may even be in your own backyard.
Yarrow’s history of medicinal use is long, varied, and better documented than other folk remedies. The soldiers of ancient Rome and medieval Europe used it in their poultices to treat wounds; in The Iliad, in fact, Homer explains that the centaur Chiron taught Achilles how to use it—and from him, yarrow inherited its Latin name: Achillea millefolium. Indigenous Americans also used yarrow in various ways for pain relief. It’s a natural antiseptic that can stanch blood flow, reduce fevers, aid digestion, and treat inflammation—a virtual cure-all.
But what about its flavor? In some ways, its character is akin to hops—bitter and astringent, with an anise- or licorice-like spiciness. On its own—for example, if brewed as a strong tea—its flavor tends to match its properties: downright medicinal. Many say it tastes like cough syrup, and that’s no coincidence—the bitter compounds are similar.
Doesn’t sound great—on the other hand, we don’t typically drink straight hop tea or chew on T-90 pellets, either. When used as a spice, in balance with other ingredients, yarrow can bring a different but distinctly herbal dimension to a concoction—as it does to Italian amari and many other European bitter liqueurs.
Yarrow in Beer
Plenty of small-batch brewers have taken a stab at brewing with yarrow in everything from historically inspired gruit ales to pilsners and ponderous imperial stouts. Its most successful applications, however, may be in mixed-culture beers that combine it with a bit of acidity.
“We find its flavor to be truly unique,” says Matt Sampson, founder and brewer at Sway Brewing and Blending in Baileys Harbor, Wisconsin. “When paired with our house mixed culture of yeast and bacteria, we get a beautiful combo of salted lemon, ginger, anise, and thyme or sage.” (For much more about Sway, see our Case Study in the Brewing Industry Guide.)
Sway’s approach to flavor and foraging is part of what recently earned it a rare honor: This year, the brewery is a James Beard Award nominee for its drinks program. Besides a range of session-strength lagers and pub ales, Sampson also brews a line of County beers. Each of these oak-fermented, mixed-culture saisons features a different locally foraged ingredient, such as chanterelle mushrooms, dandelions, goldenrod, spruce tips, or yarrow.
“We prefer to pick yarrow in the second half of June, when the flowers have just emerged,” Sampson says. “We find it growing naturally along the side of many country roads, in prairies, pastures, and other fields throughout Wisconsin. It likes full sun and dry soil.”
Depending on where you live, the growing season and ideal pick time might differ. And while there are other types and colors of yarrow, Sampson says he’s only tried brewing with the white-flowered type that’s common across North America.
Given the plant’s distinct flavor, a little can go a long way. “Yarrow flavors and aroma can become intense quickly—medicinal, overly spicy,” Sampson says. “Err on the side of using less on your first try.”
He forages the day before brewing, processing the plant during a mash rest or other downtime. “I typically harvest about twice as much yarrow as I need, by weight, before processing,” he says. “I zip the fern-like leaves off the main stem and cut the large flowers off the main stem to achieve three types of yarrow: leaves, flowers, and stems.”
He then sorts those yarrow bits into two additions, with the first going into the kettle with 45 minutes left in the boil and the second going in at flameout. The kettle addition is all leaves and stems, while the aroma addition is about 2:1 flowers-to-stems, by weight. To contain the yarrow in the kettle, Sampson uses cotton-mesh sacks that can be easily removed.
Sway’s hops are all Wisconsin-grown—another local touch—but for the yarrow saison, Sampson considers the hops to be optional; he’s brewed it both with and without them.
“The hops will help tame any lactic-acid production from Lactobacillus that may be present in your mixed culture,” he says. “The hops also help head retention and make the beer taste more ‘beer-like.’”
When brewed without hops, the head retention suffers—but then the mixed culture develops more acidity, “to a level that I really prefer in this recipe,” Sampson says. And there’s an unexpected bonus: “The lemon-like acidity that develops without hops really pairs nicely with our yarrow’s ginger-anise-thyme notes.”
It also offers an intriguing glimpse of what some beers may have been before hops took over the brewing world.