SAUMUR, France - Steam rising from floor vents swirls around the base of century-old stills in the Combier distillery in the Loire valley.

Jean-Pierre Plisson, a veteran of nearly four decades at the distillery, moves around the 10 stills, hefting sacks of pungent herbs and dried plants across the cold chamber to a scale, where he weighs out ingredients for a closely guarded formula for absinthe.

The herbal, licorice tasting drink, which according to lore drove Vincent Van Gogh crazy and fired the poetry of Charles Baudelaire, is technically still illegal in France.

But an alliance of the distillery's owner, an American absinthe connoisseur and a New York law firm is working to bring the absinthe revival back home — gradually chipping away at legal restrictions rooted in myths about the supposed dangers of the "Green Fairy," as the drink was once known.

After nearly a century of prohibition, absinthe has enjoyed a cult boom of sorts in the United States, where it became legal to produce and sell the spirit in 2007.

But the drink — which under French law must be called "Absinthe-based spirit" in order to be sold legally — remains extremely rare in French bars and cafes where it once rivaled wine in popularity until it was banned in 1915.

Part of the drink's attraction stems from the ritual involved in serving it — with an elegant glass or crystal fountain slowly dripping ice-cold water onto a sugar cube placed on a slotted silver spoon. The water and sugar drip into the glass, turning the spirit a milky white or soft jade color. Today the most demand for absinthe is found in the U.S., France and Switzerland.

During the nearly century-long absinthe ban, Combier built a reputation for other alcoholic drinks, such as triple-sec, as well as flavored syrups used by bartenders to make cocktails.

Plisson, 55, is the nearly two-century-old distillery's longest-serving worker. He tends to the 100-year-old stills, whose copper tubes arch across the room like spider legs into a cooling apparatus designed by Gustave Eiffel — the creator of the Eiffel Tower.

The French law that banned absinthe is still on the books. A separate decree until recently defined absinthe as a beverage whose concentrations of three molecules found in the plants used to flavor it exceed certain thresholds. The proportions have been changed numerous times during the drink's prohibition — most recently in March, when efforts by Combier and its American allies persuaded the government to remove thresholds for two of the substances.

As long as distillers like Combier limit their use of wormwood — one of the plants along with fennel and hyssop that give absinthe its characteristic taste — their drink is legal. It just can't be called absinthe.

The wormwood plant contains thujone, a molecule that was once blamed for causing hallucinations and brain damage. Such fears were unfounded, modern science has since proved, but were used by abstinence campaigners and competitors in the wine industry to drum up public opposition to absinthe that led to the ban.

In fact the stories of thujone-induced hallucinations were pure myth, and experts agree the drink is no more or less dangerous than any other strongly alcoholic drink such as whisky, vodka or gin.

"The nearly unanimous view of experts is that the toxicity of absinthe comes exclusively from its high alcohol content," said Dr. Jean-Pierre Luaute, a psychiatrist who has written scientific articles and books on the subject.

In very high concentrations thujone can cause convulsions in animals, Luaute said, but "in fact there is very little thujone in absinthe, even the vintage ones," he said.

While French distillers can't call their drink absinthe and must tweak the recipe slightly to get around legal restrictions, they insist the product is basically the same.

"My recipes are traditional recipes," said Franck Choisne, owner of the Combier distillery. He and his American partner, the absinthe connoisseur Ted Breaux, set out a few years ago to recreate absinthes that matched the original, pre-ban absinthes as closely as possible.

Experts agree.

"It's absinthe, it's made with the same plants as back then, with essentially the same recipe," said Fabrice Herard, an absinthe expert who is working on setting up an "Absinthe Road" tourism circuit in eastern France, once the center of French absinthe production.

After much initial success, Choisne and Breaux had to stop production of some of their most expensive and sought-after absinthes, some of which go for over $100 a bottle, after inspectors tested the drink and said it was illegal.

Ironically, the problem was not the wormwood but another of absinthe's ingredients: ordinary fennel.

Distillers like Choisne and Breaux were reluctant to cut down on the fennel to bring their absinthe into line with the regulations because of their desire to make a drink that followed as closely as possible recipes from absinthe's heyday.

The limit also struck the distillers as absurd, as their research showed that to be poisoned by fennel, someone would have to drink enough absinthe to fill an Olympic swimming pool. "You'd be killed by the alcohol long before the fennel," Choisne said.

They turned to New York law firm Nixon Peabody, which had helped overturn the U.S. ban in 2007. Arnaud de Senilhes, the head of the firm's Paris office, liked the two distillers' case and led their fight to change the decree.

The new decree, published in March, removes limits on the amount of fennel and hyssop, and leaves unchanged the threshold for wormwood.

The change will permit Combier and Breaux to reintroduce the absinthe brands they were forced to stop making in 2006. They still can't call their drink "absinthe" in France, though, so the two distillers and their lawyer say their next step is to overturn the 1915 law.

Meanwhile, drinkers in Paris' bars and bistros are just starting to get reacquainted with the drink.

"You don't find it too much in bars in Paris," said Mickey, the owner of Cantada II bar in the 11th arrondissement. On its Facebook page the bar calls itself the biggest absinthe bar in France, with more than 25 different bottles behind the bar.

"Some people are surprised to see it, they think it's still illegal," said Mickey, who uses only one name.

The bar owner prepared a glass of absinthe in the traditional way. The method is mainly for show, though Choisne said the slow dripping of water into the absinthe helps to release the spirits' bitter herbal aromas.

He served it to Lea, a 19-year-old student with a nose ring and a flower in her red hair.

"It tastes like pastis, but sweeter, a little bit floral," she said.