Special Ingredient: Bog Myrtle

Also known as Myrica gale, this mud-loving shrub was once a key ingredient in the unhopped ales of medieval Europe—and it has a unique character worth considering for your beers.

Joe Stange Oct 12, 2021 - 5 min read

Special Ingredient: Bog Myrtle Primary Image

Photo: Henrik Larrson, Shutterstock

Before hops gained ground as a beer ingredient, brewers in the Low Countries made gruit. The herb mixture used to flavor those unhopped ales was a key to local power—and bog myrtle was a key ingredient in that mixture.

Also known as Myrica gale, sweetgale, sweet willow, besides many other names, bog myrtle is happiest in the moist and muddy areas of northern climes. The flowering shrub grows in the northernmost United States and most of Canada as well as it does in Northern Europe. Perhaps more numerous than its names are its folk uses: tea, medicine, and insect repellent, to name a few.

Along with mugwort and yarrow, it’s also one of the best-known ingredients in medieval gruit—so, inevitably, some modern brewers also have taken a whack at making beer with it. The Treboom Brewery of North Yorkshire, England, for example, brews Myricale, a pale wheat ale infused with bog myrtle. In Denver, TRVE Brewing collaborated in 2019 with Danish brewery To Øl on a mixed-culture sour beer called Myrican Viking.

Given gruit’s former importance in Belgium, it’s no surprise that bog myrtle grows well there—nor that a few Belgian brewers like to use it as an ingredient. One of the better-known examples is Gageleer, a strong ale brewed by Proefbrouwerij for the Kempen region (where the plant is called gagel).


Bog Myrtle at Antidoot

A less conventional outfit that likes brewing with bog myrtle is Antidoot Wilde Fermenten, a brewery/winery/cidery based in Kortenaken, Flemish Brabant, about 60 miles east of Brussels. Brothers Tom and Wim Jacobs are specialists in wild fermentations using indigenous yeast and bacteria—and often indigenous ingredients, such as bog myrtle.

“We tried it a few times in homebrew experiments,” says Tom Jacobs, “and we were at first surprised that it was more antibacterial than the other herbs we were using. In those experiments, we were not using any hops at all, trying to find out about the possibilities of herb-forward beers, like in the old times. At the same time, we were intrigued by its distinct aromatic profile.”

That profile is unique, he says. “It has a strong, eucalyptic kind of aroma, both the flowers—which turn into little pine-like cones—and the leaves. The aroma is easily transferable to the beer. We normally steep it at the end of the boil or in the coolship. It can become a bit medicinal in aroma, but at the same time you still have that eucalpytic freshness together with a bit of a spicy and bitter taste.”

Antidoot used it in Nacht van de Geit, brewed after the 2018 Carnivale Brettanomyces in Amsterdam with several other funk-friendly brewers: Bretty Fingers of Sweden, Nevel of the Netherlands, Kemker of Germany, and California-based Tim Decker of the AltBrau podcast. Each brewer brought a local plant, and the beer—Nacht van de Geit, or “Night of the Goat”—also included bay laurel, bedstraw, hogweed, and artichoke leaves. The result was a sort of funk-forward international gruit.

In the Jacobs’ view, beers with bog myrtle—as well as other herb-forward beers—benefit from wild and mixed fermentation. “Especially because you need a bit of acidity,” Tom says. “Without the tartness, they easily become a bit heavy. Also, it’s intriguing to give them enough time in the barrel, as there are a lot of complex components coming from the different herbs. Time gives them the opportunity to become more integrated, together with eventual biotransformation by Brettanomyces.”

While it’s cool that bog myrtle once was used in gruit, that’s not the point for Antidoot. “Personally, our concern is not about historical accuracy,” Tom says. An example: For their last brew of the coolship season in April (pictured below), the Jacobs brothers added bog myrtle to the coolship for a eucalyptus aroma hit. Now the beer will mature, and next year they want to macerate and add bitter and blood oranges to the beer.

“We approach them from a gustatory-culinary perspective, combining them in ways that fit our palate.”