Mugwort and other weeds become the stars of botanical beers

Chaga Groove, a botanical beer by Earth Eagle Brewings of Portsmouth, N.H. Earth Eagle Brewings

Butch Heilshorn offers a straightforward explanation for a career path that has led him to being one of the country’s foremost brewers of botanical beers.

“I think the big thing was marrying an herbalist,” Heilshorn says wryly.

Heilshorn is the cofounder of Portsmouth, N.H.’s Earth Eagle Brewings, and the author of a new book, “Against All Hops: Techniques and Philosophy for Creating Extraordinary Botanical Beers.”

Botanical beers, also known as gruits, have been brewed throughout the world for centuries. As the book’s title suggests. they’re beers spiced with herbs and ingredients other than hops. Earth Eagle brews hoppy beers, but those are a product of Alex McDonald, Heilshorn’s cofounder and brother-in-law.

Heilshorn is the botanical beer guy, which means he’s constantly scouring fields and forests for ingredients.

“There’s an amazing array of goodies out there in everyone’s back yard or an abandoned lot,” says Heilshorn. “You of course have to be careful about where you’re sourcing from.”

Sweet fern and mugwort grow all over New England, and are among the readily available plants that make for good drinkin’.

“They’re basically ditch weeds, the ones you’re pulling out next to the foundation in your house,” Heilshorn says. “I get a real thrill out of that.”

Heilshorn’s book is full of recipes for beers like Birthday Boy, a Belgian pilsner that includes the aforementioned mugwort, which Heilshorn writes “has a long history in herbalism primarily to help with female issues.” Other ingredients in Birthday Boy include motherwort, spruce flowers, and burdock root. One Beer Advocate review for the beer says it tastes a little peppery and smells “like literally almost smelling earth.”

Medicinal qualities are attributed to many of the beers Earth Eagle brews, though many haven’t been proven by science. Heilshorn often collaborates with his wife on the best herbal combinations to make people feel good and to avoid any adverse reactions. They are constantly experimenting: Since opening in 2012, Earth Eagle has registered 275 recipes with the state.

Not every botanical beer is a success. In five years Heilshorn says he has had to dump a handful of batches.

“As you can imagine these herbs vary tremendously in strength,” he says. “It’s funny what kind of folks some of these beers will bring out of the woodwork. We made this absinthe beer that was horribly bitter. We released a little, and there was a small cadre of people who said it was the best beer ever.”

Earth Eagle Brewings is located at 165 High St., Portsmouth, N.H.