An assortment of New World vermouths, hailing from California, New York and Oregon. (Deb Lindsey/For The Washington Post)

Would a vermouth by any other name sell as sweet?

American vermouth producers might start wondering. Some of their products have stirred an international scuffle, raising the question of how much the inclusion of artemisia, a single genus of plant, defines an entire category of fortified wine.

Vermouth in its dry manifestation softens your martini; in its sweet one, it enriches your Manhattan. While the history of aromatized wine goes back even further, some classic European vermouth brands have been around since the 1700s. And in Europe, the use of artemisia is considered fundamental in true vermouth.

There are hundreds of species of artemisia. Artemisia tridentata, a.k.a. sagebrush, has conquered our northwestern plains, bullying its silvery way into the role of Nevada’s state flower. Artemisia vulgaris, known by the Harry Potteresque “mugwort,” is viewed by plant nativists as an invader but is much adored by butterflies. Artemisia dracunculus — tarragon — sends its anise-y green scent up from the béarnaise sauce swaddling your steak.

But the species at the heart of the matter is Artemisia absinthium: wormwood, the plant that launched a thousand regulations. Once reviled for its hallucinogenic effects (mostly mythical), still feared for its neurotoxic chemical thujone (dangerous only in extremely high doses), wormwood is equally admired by those who have, for centuries, praised its healing properties and the deep, complex bitterness it brings to the palate.

Although it developed much of its bad-boy reputation from its presence in absinthe, wormwood, from the German “wermut,” is the very root of the word “vermouth.” While European regulations defining vermouth, reaffirmed and updated in January, require only the use of “appropriate species of artemisia,” without spelling out what those species are, most European vermouth producers hold sacred the use of wormwood.

Stateside, though, the Alcohol and Tobacco Tax and Trade bureau’s requirements for an aromatized wine to be labeled as vermouth leave the door tantalizingly open, employing a tautological head-scratcher: “Vermouth is a type of aperitif wine . . . having the taste, aroma, and characteristics generally attributed to vermouth.” The product, in other words, is partly defined as one that tastes like itself; if it quacks like a vermouth, it is one.

Like absinthe, vermouths containing extracts from plants with thujone are subject to safety tests, creating a cost-and-time factor that has played into many domestic vermouth makers’ decision to avoid the herb entirely — and inviting charges from established European brands that American producers don’t respect the wine’s long history. Whatever is in those bottles, traditionalists argue, it’s not real vermouth.

“They can be called ‘aperitif wine.’ But the reason they’re putting ‘vermouth’ [on the label] is because it’s a trend now with bartenders,” says Giuseppe Gallo, global brand ambassador for Martini & Rossi.

Yes, vermouth is big now. The term “golden age” was uttered by more than one of my sources. Twenty years ago, that would have seemed laughable. The drink “had become very much a commodity-only kind of product by the time the interest in cocktails started rebuilding in the mid-’90s,” says Martin Doudoroff, publisher of “We had the mass-market Martini & Rossi products and the Cinzano, and that was about as good as it got . . . . The first big rock to hit the pond was Carpano’s Antica Formula, which just rewrote everyone’s expectations.”

It rewrote mine. The first time I had Carpano, in a Manhattan made by Jeff Faile, bar experience director for the Neighborhood Restaurant Group, I was struck by its lushness, its rich notes of vanilla and spice. I suspect such experiences have happened around the country: Bartenders have driven American interest in vermouth, and a few of them have taken their interest to the next level, becoming producers themselves.

Bianca Miraglia of New York-based Uncouth Vermouth and Neil Kopplin of Oregon’s Imbue began making their own vermouths after years of experimenting behind the bar. Although they were inspired by the European tradition, they aren’t trying to replicate what’s been coming out of France and Italy for centuries.

Miraglia’s products, in particular, swerve off the beaten path. “I was trying to make something that previously had not existed,” she says. Foraging local ingredients, including Artemisia vulgaris, Miraglia makes vermouths in flavors such as apple-mint and beet-eucalyptus. She’s aiming for seasonality and is delighted when one batch is different from the next. And she loves the new American vermouths, which, she says, have little in common with one another. “It’s probably why we all get along so well,” she jokes. “There’s another vermouth producer here in New York . . . . I love his vermouth. And it’s absolutely nothing like mine.”

The diversity Miraglia loves scares the bejeebers out of some traditionalists. Her line is particularly unusual. But take Imbue’s Bittersweet Vermouth. Pale gold and based on pinot gris grapes, it’s a touch sweeter than a classic dry and has a softly bitter finish. It makes for an odd but tasty drink, a bit like the so-called “perfect” martini, which uses equal parts dry and sweet vermouth.

No, Imbue doesn’t quack exactly like a dry French duck (and, I would argue, the label tells the consumer not to expect one). But it seems to do fine as an Oregon bittersweet loon. Is its divergence so great that it doesn’t warrant the name “vermouth”? After all, Kopplin points out, while Imbue doesn’t contain wormwood, even the European regulations don’t say you have to use it. One of the herbs in Imbue is in the artemisia family, “so technically we could still call ourselves vermouth. But a European producer would call me out on that.”

Now that Imbue has gotten a foothold and isn’t on quite as much of a shoestring budget, Kopplin says, the prospect of spending time and money on thujone testing doesn’t seem as daunting. Kop­plin expects that future versions of Imbue will contain wormwood. “But is it going to add anything to the flavor or aromatics of what we do? Probably not.”

The importance of the herb goes beyond the issue of regulations, Doudoroff says. While “you could probably arrange to have one part per billion, measurable with lab equipment, to prove ‘Yes, I have some artemisia in my product,’ that’s clearly not really a reasonable test, either. It’s more like, does it taste and work like a vermouth within the tradition?”

There are people who would argue that’s an unacceptable limitation. “But there are people with entire lifetimes of experience making vermouth in Europe who would argue that that’s no limitation at all, any more than having to put juniper in gin is a limitation.”

Kopplin says he didn’t get into the business to thumb his nose at tradition; he loves the whole vermouth category. Still, he says, “I’m not a huge fan of Europeans . . . telling us how to do our business. We invented the automobile, but we don’t get pissed off when French producers make something and they call it an automobile, too.”

I found myself nodding along, ready to follow him up the beachhead chanting “USA! USA!” until I remembered that the automobile was invented by a German. Even so, is that the right analogy? What if the French made a motorcycle and called it an automobile? What if they made a bright orange helicopter with a weird beepy horn? There are, among the New World vermouths I’ve tried, some that are pretty close to an automobile and a few that, while delicious, are more like that helicopter.

It seems iffy to focus only on American innovations, though. Martini & Rossi’s recently released Gran Lusso is an unusual-for-vermouth mix of red and white wines. Thyme-y on the palate, it includes in its ingredients red cinchona bark, which lingers on the tongue with a woody, bitter finish. You could argue that the cinchona is more prominent than the traditional wormwood bitterness. But the wormwood is there, so the litmus test is passed.

Back to those rules, though: If I were a producer looking to get into the vermouth trade, I’d be questioning whether they’ll remain the same.

Peter Schaf, co-founder of Tempus Fugit Spirits, which aims to launch two Italian vermouths in the United States within the coming months, has spent years studying the history of spirits and says wormwood should be in vermouth as a matter of principle.

But he also thinks that international agreements eventually will protect that standard. The Europeans, he notes, have been pushing toward protection of European Union product definitions and regional names. Related to the long-standing rules for the use of the term “champagne,” some foods and beverages that don’t have a legally defined geographical origin are instead defined by methods of production. That might come into play with vermouth — and if it does, Schaf suspects the definition will side with its historic origins, and with that bitter little plant.

Allan is a Takoma Park writer and editor. On Twitter: @Carrie_the_Red.

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