The first thing you notice when you arrive at Domaine de Rombeau is a jumble of wine-filled orbs, each one tucked into the dirt, glowing orange-yellow in the sun like a preternatural pumpkin patch. Philippe Raspaud de La Fabrègue, export manager for the winery, located in Rivesaltes, in Roussillon, invites us to taste some of the liquid inside: buttery on the palate, with a spicy fenugreek note and a faint hint of chlorinated water on the nose, it recalls memories of long summer days spent sunbaking by a pool. This is what Raspaud calls le goût du soleil—literally, the taste of the sun.

The wine in these demijohns is destined to be blended with other wines currently aging in oak barrels, which are similarly exposed to the elements, to form Rombeau’s rancio sec—a style of oxidatively aged, dry wine native to the Catalonian region, in this part of southern France. The production facilities for Rombeau’s rancio sec are splayed out, higgledy-piggledy, in a patch of pine forest littered with farming equipment and old barrels—some in direct sunlight, others sheltered. Even the demijohns are sealed from the elements not with cork stoppers but with upside-down Nutella jars, rubber-banded in place.

Three Rancio Sec Producers to Know Terre des Templiers Terre des Templiers is by all accounts the largest producer of rancio sec in the world—not that this means much: their annual output is only 4,000 bottles. Despite exemplifying rancio sec at its most industrial, their product is surprisingly nuanced. “Even though the producer is large, this is not a commercial product for them,” says Eric Seed, of Haus Alpenz. Jolly-Ferriol If there is a connection between rancio sec and the Roussillon’s natural wines, it owes much to Jolly-Ferriol, who is among the region’s first naturalist producers to tap into the rancio sec tradition. Their Au Fil du Temps rancio remains a benchmark for the category. Domaine Laguerre One of the key differences between rancio sec and fino or manzanilla sherries is that the former, generally speaking, does not age under a veil of yeast—except, of course, when it does, as is the case with Domaine Laguerre’s Oxy rancio sec, one of the most idiosyncratic bottlings on the market today.

This ramshackle approach to rancio production is not an anomaly in Roussillon. Rancio sec was, until recently, strictly for local consumption: a traditional product that winemakers would set aside for family and friends. These wines are made by vinifying local grape varieties—usually macabeu, grenache blanc and grenache noir—and aging in exposed conditions, where heat, light and oxygen combine to transform the final product. This process destroys the primary fruit characteristics and replaces them with complex tertiary flavors and aromas, like cocoa, curry and walnut. Pierre Torrès, a historian of Roussillon’s wines, argues that this practice dates back to ancient Roman times, citing a passage from Roman historian, Pliny the Elder, describing wines exposed to “all the insults of the air.”

Until recently, it was nearly extinct. In fact, in 2004, rancio sec was declared an endangered viticultural tradition by Slow Food International. As a means of protection, a small and dedicated band of producers lobbied the French government to create separate Indication Géographique Protégée (IGP) rules for rancio sec producers to follow. Those rules are extremely lax by French standards: the wine must be oxidatively aged for five years; it must be made from a base of the Roussillon’s typical grape varieties; and it must not contain any residual sugar. Beyond that, most decisions are left in the hands of the producer, which leads to a fascinating diversity of production methods and expressions.

At Jolly Ferriol in nearby Espira de l’Agly, best known for their exuberant pét-nat, wines destined to become the estate’s rancio sec are aged in demijohns for three years before being transferred to a solera, where they mingle with older wines for at least two years before being bottled. Meanwhile, the rancio sec from Domaine des Schistes, a naturalist estate in Estagel famed for their Muscat de Rivesaltes, is aged only in an indoor solera. And at Domaine du Mas Blanc, a legendary producer of sweet Banyuls wine, Jean-Michel Parcé is aging his first, yet-to-be bottled rancio sec in a single five-hectolitre barrel just barely exposed to the elements. While the results share certain characteristics—particularly the nutty notes that indicate oxidation and a characteristic hint of fenugreek—these rancio secs range wildly in terms of color, flavor profile and depth of oxidation.

That an institution as established as Domaine du Mas Blanc has just begun making a rancio sec for export is indicative of the paradoxical position that this ancient wine category now finds itself in. On the one hand, there are probably more people interested in rancio sec right now than there have been at any prior moment in its history, thanks to the steadily growing reputation of natural wines from the Roussillon and the work of local vignerons to promote the category. On the other hand, rancio sec forms only a minuscule portion of any of its producers’ outputs—even the largest producer of rancio sec, Terre des Templiers, produces only 4,000 bottles of the stuff annually.

“It’s something that’s unknown; no one’s heard of it, and no one’s asking for it,” says Eric Seed of Haus Alpenz, a company that imports eight producers’ rancio secs to the United States. “With a name like ‘rancio’, which sounds like ‘rancid’, it’s not an easy proposition [to sell].” He’s committed to importing it not because of an overwhelming demand for the product, but because “it is a historically important style of wine, one of the oldest forms of dry winemaking.”

Making Rancio Sec Philippe Raspaud de La Fabrègue, export manager for Domaine de Rombeau, and winemaker Fernand Baixas taste rancio sec. Baixas pulls rancio sec from barrels in the yard. Demijohns, called bonbons in French, sit in the yard at Domaine de Rombeau. The historic house of the de La Fabrègue family of Domaine de Rombeau. In a barn where they keep some of their stock, de La Fabrègue talks about his family’s wines. de La Fabrègue walks the yard at the winery. Casks of rancio sec age in the yard at Terre des Templiers in Banyuls sur Mer. Banuyls sur Mer rises from the beach. A vineyard is perched on the cliffs above the sea south of Banuyls sur Mer.

The recent uptick in interest in Roussillon’s natural wines has helped bring attention to the category, as many of the region’s naturalist producers make a rancio sec as a matter of course. “The production of rancio sec is fairly non-interventional,” says Seed. “You’re not sulfuring up your barrels, you’re not intervening to prevent oxygenation—au contraire. For a natural winemaker, it makes good sense.”

However, Isabelle Jolly of Jolly Ferriol, who was among the first natural wine producers in the area to make a rancio sec, warns against the temptation to conflate the category with natural winemaking: “Just because it is an ancestral wine, a typical wine of Roussillon, it is not necessarily natural wine for all the winemakers [who produce it],” she says. (She predicts that this will change in the next five years or so, when more natural winemakers respond to growing interest in the category by releasing their own renditions.)

Like sherry, a category of fortified wines from southwestern Spain that range in profile from bone-dry to sticky sweet, when rancio sec was nearly forgotten to history, it was the region’s culinary traditions that kept it alive. And like dry sherry, it’s typically served as an aperitif or alongside seafood, like the Roussillon’s famous anchovies. But the easy comparison to dry, oxidatively aged sherries, like amontillado or oloroso, isn’t a perfect one, even if they share both a commitment to savory flavors, solera aging and status as some of the world’s most singular wines.

“They are quite different,” says sommelier Pascaline Lepeltier, “between the grape varieties, which have way more personality in the Roussillon, the aging, the climate…” And while sherry has enjoyed something of a modern renaissance, not only among sommeliers, but bartenders as well, rancio sec is “still a very secret category,” she says. What small success it’s had in the United States has been down to a small group of bartenders and sommelier proselytizers, such as Alex Uribe, beverage director of Bistro Campagne in Chicago, and Chaim Dauermann of New York’s The Up & Up.

While part of rancio sec’s current appeal no doubt derives from the broader interest in both oxidatively aged and minimal-intervention wines, its biggest selling point is the fact that it remains so resolutely idiosyncratic. It’s a point that, Jolly notes, is illustrated in its very name: the French word rance, from which the name rancio sec derives, translates into English not only as ‘rancid’, but also as ‘tough’ and ‘persistent’—two characteristics that have served rancio sec well throughout the years, and place it in good stead for whatever the future has in store.

“Not only does it illustrate the history of Catalan winemaking,” says Uribe, “[it] shines a light on where our tastes, our drinking preferences, are going.”