Where the Rare Citrus Grows

AS OF LATE, the center — which isn’t open to the public — has also become a pilgrimage site for French chefs, pâtissiers and fragrance-house noses, who often learn about it from their own suppliers; many citrus trees at pedigreed French farms can be traced back to buds and seeds from San Giuliano’s orchard. Pierre Hermé, the master of French macarons, visits every summer, as does Anne-Sophie Pic, a three-Michelin-star chef based in Valence, ready to sample a mild, sweet Israeli pomelo or an acidless ancient Italian orange with a subtle vanilla scent.

While the institute doesn’t compete with commercial producers, it has been known to make gifts of the rarest varieties; some chefs, like Pic, arrive with an empty bag. Back at her namesake restaurant, she plates honey-flavored Murcott tangor alongside skinless cherry tomatoes and crowns the meringue of her île flottante dessert with the zest of the American Wekiwa tangelolo, its floral flavor the result of breeding a grapefruit-tangerine hybrid with another grapefruit. These tasting expeditions at San Giuliano have inspired not only Pic’s menus but those of other leading French chefs as well, including Fabio Bragagnolo, who runs Casadelmar in southern Corsica, where he garnishes roast lamb with candied slices of syrupy, bitter Chinotto orange.

Contemporary French cuisine, of course, relies above all on the country’s specialized produce, terroir and agricultural heritage, and there are similar government-run parcels for cherries in Bordeaux, alliums in Brittany and nightshades in Avignon. As public institutions, they collect exhaustively, a luxury inaccessible to commercial farmers who remain subject to the whims of shifting consumer tastes and profit margins. In that way, the citrus conservancy serves as a corrective of sorts, a place where chefs can be inspired by the wildness of an entire genus, where a familiar yellow lemon grows beside its ancestors, the sour orange and the citron, but also its baroque cousins, like the blood lemon, marked by vivid red streaks on its rind, and the Beldi lemon, an aromatic Moroccan variety with hints of bergamot — all of which are descendants of a few distinct Southeast Asian citrus trees. “You might think you know a fruit,” says the chef Pierre Sang Boyer, who runs three popular namesake restaurants in Paris’s 11th Arrondissement. But at San Giuliano, “you learn it has a history — and you learn how nature works.”

Citrus: Courtesy of CRB Citrus and Citrus Breeding INRAE ​​CIRAD