It is one of the immutable laws of distillation: Anything that exists in the natural world will eventually end up flavoring some kind of booze.

A second rule: At some point, that spirit has a good chance of getting banned.

So it was for most of a century with wormwood-laced absinthe, and so it is today with authentic bison grass vodka, a spirit that is scented with the plant known as Hierochloe odorata in Latin; other names for it include sweet grass, manna grass, Mary’s grass, vanilla grass, and holy grass. A cherished drink in Poland, Russia, and other parts of Central and Eastern Europe, bison grass vodka — a.k.a. zubrowka — owes its flavor profile to the presence of coumarin, a colorless chemical compound with a complex, vanilla-like aroma.

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Due to its pharmaceutical properties, coumarin has not been allowed in food or drinks in the United States since 1954.

Smuggling it in

In addition to bison grass, coumarin is naturally present in many plants that are beloved as flavorings and aromas, including tonka beans, cassia cinnamon, and woodruff. While dangerously large amounts are not allowed, European regulations on the presence of coumarin in food and drink are less strict than in the U.S.

As such, bison grass vodka remained an Old World specialty for many decades, occasionally brought in undeclared in travelers’ suitcases or showing up as not-quite-legal imports in restaurants and shops in Eastern European neighborhoods in bigger U.S. cities.

But since 2010, the main producer of zubrowka has made a coumarin-free version of the drink that is legally imported into the United States. (Confusingly, zubrowka has been used as the term for a type of spirit in the United States, like whiskey or gin, though just one producer, Polmos Białystok, uses Zubrowka — with a capital Z — as its brand name.)

For connoisseurs like Max Ionikh, chef and owner of Red Square Bistro in Denver, the coumarin-free U.S. import of Zubrowka works just fine.

“I have tried the Polish version, and honestly I could not tell the difference,” he says. “I know that coumarin is a blood-thinning agent and, therefore, not allowed in the U.S. I’m not sure of the process of lowering it or how they eliminate it from the spirit, but we sure are glad that the vodka is available here.”

Both the coumarin-free version and the original have a very complex flavor profile, going well beyond mere vanilla, Ionikh says.

“I usually describe the flavor of the vodka as very savory,” he says. “Depending on a person’s palate, one can taste vanilla, hints of tarragon, cinnamon, or heather honey.”

Those flavors have made the drink a favorite in vodka-loving cultures. However, cognoscenti like Anton Galkin, vodka sommelier at the Ritz-Carlton Moscow, will note that zubrowka — lightly tinged yellowish-green and brightly scented by its contact with the bison grass — is technically not a vodka.

“Zubrowka is a classic herbal infusion and cannot be called vodka,” he says. “Regular vodka is of crystal clear color, without any additional smell or taste.”

Those additional smells and tastes make zubrowka very interesting for food pairings. In particular, Galkin recommends charismatic, Old-World drinking snacks.

“The best pairings for zubrowka are salted or smoked lard, Russian-style pickles, aspic, or Russian brown bread with garlic,” he says.

When it comes to mixing, zubrowka harmonizes particularly well with fruity flavors, especially apple. In Poland, the most common cocktail is the szarlotka, a highball-like mix of zubrowka with apple juice in a 2 to 5 ratio; its name is borrowed from the Polish name for apple charlotte. Other drinks like the Frisky Bison (a.k.a. Polish Kiss) play on similar themes, employing apple cider, apple liqueurs, apple vodka, or other fruit-based spirits.

Although Polmos Bialystok Zubrowka is by far the biggest brand, it’s certainly not the only maker. In Poland, the Sobieski distillery has produced its Bizon Grass Vodka, while Polmos Lancut makes Wisent, using another name for the nearly extinct European bison. In Germany, there’s Grasovka. In Belarus, several versions can be found, including Bulbash 6 Bison Grass and Zemlyak Countryman Zubrowka, a “tincture” made by the JSC Gomel Distillery.

Those who have trouble reading Polish or Belarusian should look past the letters on the label. Most versions contain a blade of bison grass inside the bottle as a visual cue.

Growing your own

Considering the interconnectivity of the world today, it’s hardly surprising to find bison grass moving beyond its traditional role in Eastern Europe. Nick Wadeson, owner and distiller at Three Wrens Gin in Cheshire, England, became fascinated by the plant’s aroma during his previous career working behind the bar.

“I was a cocktail bartender for years and years in Manchester, and I used bison grass vodka in a lot of drinks and absolutely loved it,” he says. “We did one with pear, blackberry and apple juice, which worked really, really well. And then we’d stick to the things that we know pair well with apples, like elderflower, which famously goes well with apple juice. I just think that that aroma of coumarin is just a really underused thing, because it has been confined to the world of vodka.”

Memories of those drinks inspired Wadeson to try using bison grass in one of his craft gins, though that wasn’t as easy as he initially imagined.

“As a distiller, working with botanicals every day, I just had a good idea that it would work harmoniously with other ingredients, rather than just being confined as the main flavor in a vodka,” he says. “So we set about the task of trying to find some, and then realized you couldn’t buy it anywhere.”

Unable to source bison grass, Wadeson enlisted the help of a botanist friend, who couldn’t actually get the plant. What he could get were bison grass seeds, which Wadeson then planted in a small patch behind his distillery. Progress was hindered, he says, by a very low germination rate.

“Most of the seedlings died, but a few of them survived and we ended up having a reasonable enough haul of the grass to start doing some trials,” he says. “We paired it with other ingredients that we can grow here like lemon thyme, which is really complementary, and then we added some spice by using some ginger.”

Wadeson’s experiment appears to be a resounding success: Just last month, Three Wrens Bison Grass Edition won best flavored gin at the 2021 Great British Food Awards.

That could mean that, once tourism starts up again, U.S. travelers to Europe will have a brand new spirit to try to sneak back inside their suitcases.

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