Sous vide, now the rage among many ambitious chefs, is not for every cook. The term is French for “under vacuum”; it sounds much nicer than “vacuum packed” and more euphonious than “boil-in bag” or “Cryovac”—the food-grade plastic that has become a generic label for both the process and the bags in which food is vacuum sealed, cooked, chilled, and reheated. Everything that “Cryovac” implies turns many cooks completely off sous vide. A thick plastic barrier comes between you and the food you’re cooking. It looks ugly, like something from a cut-rate super‑ market bin or, worse, a laboratory refrigerator. You can’t touch, smell, or stir what you’re cooking. When a piece of meat or chicken—which is what many chefs primarily use the sous vide method to cook—comes out of the bag, it looks like a rubber item from a joke shop.

For decades frozen-food manufacturers, airline meal services, and caterers have put entire meals in bags. So have harried homemakers, using vacuum-sealing machines like the ones advertised on late-night TV shows. Their motives are similar: extended storage that saves time and space, and good flavor results. High-end restaurants have long bought fancy entrée components in vacuum pouches, which allow chefs to offer a range of dishes their own kitchens are incapable of producing (meals just as good as first-class airplane food, in a restaurant!). In recent years cooking techniques and technology have been considerably refined (Cuisine Solutions, in Alexandria, Virginia, is the national leader), and today much first-class airline food is in fact prepared in vacuum-packed bags. Hotels and banquet halls rely on them. In France sous vide is a part of everyday life for discriminating shoppers, who buy haute cuisine meals from gleaming white-tiled frozen-food markets, and don’t hesitate to serve them at elegant parties.

In this country sous vides reputation is much more downmarket. And yet some chefs are true believers—such complete converts that practically every piece of protein in their restaurants gets packed in plastic and cooked for hours and hours in a tepid bath. These cooks trade poking and prodding, sniffing and tasting—the instincts they have acquired through years of watchful attention—for expensive packing machines, “immersion circulators” (heating tanks) and temperature probes. Their kitchens look like biology labs, with odorless open tanks quietly burbling beside uncrowded burners and griddles.

The great surprise is that some of the chefs who have wholeheartedly embraced sous vide are the ones you (or certainly I) would least expect: cooks who care deeply about the farm-to-table connection, who would almost rather be tending sheep, feeding chickens, or using homemade compost in a bed of Charentais melons than standing at the stove. The country’s two highest-profile exponents of the farm-to-table connection, Alice Waters, of Chez Panisse, in Berkeley, and Dan Barber, of Blue Hill, in New York City, are at different ends of the sous vide spectrum: Waters wants nothing to do with it, and Barber can’t imagine running his kitchen happily without it.

Or, rather, his kitchens: there is a much larger Blue Hill in Tarrytown, forty-five minutes north of the city in Westchester County. The meadows around Barber’s second restaurant actually are Rockefeller land: both the restaurant and Stone Barns, a sustainable-agriculture education center and working farm, are housed in the beautifully and sensitively renovated former dairy barns of the Rockefeller estate. I recently visited Barber in Tarrytown to learn about his fierce attachment to sous vide—and how he coped last spring with the threat that it might be severed, when inspectors from the New York City health department came to call.