Unlike the method of processing chicken in ice water, air-chilled chicken is cooled by going through chambers of cold air.

MCT / Patrick Tehan

Air-chilled is red hot.

In the world of poultry, natural, free-range and organic have become all-too familiar labels. Now, look for another one at high-end grocery stores near you: air-chilled.

The air-chilling process, common in Western Europe for more than 45 years, is still fairly new in the United States. It refers to a specific method used to cool chickens after slaughtering. Most chickens in this country are processed by being immersed in ice water. By contrast, air-chilling cools chickens by blasting them with cold air.

Air versus water? Is there really such a huge difference? Many retailers think so. Since January, Whole Foods has been steadily converting all of its full-service meat counters to sell only air-chilled chicken. Niman Ranch, known for its sustainable and humanely raised meats, is expected to start selling an air-chilled French heritage chicken called Poulet Rouge Fermiere in April. It will be the company’s first chicken product.

Whether air-chilled chicken is safer is not really clear. A USDA-sponsored study by the University of Nebraska in 2000 found that 350 air-chilled chickens had about 20 percent less bacteria (such as salmonella and campylobacter) than the same number of water-cooled poultry. That study, though, examined only one air-chilling plant and one water-immersion plant.

“I do prefer this type of chicken. Whenever I can find them, I buy them,” says San Francisco food scientist Harold McGee, author of the fundamental On Food and Cooking: The Science and Lore of the Kitchen” (Scribner), who became a fan of air-chilled chicken when he lived in France.

“The basic fact that you’re not adding anything extraneous to the chicken is the most important to me. If you’re buying chicken, you want chicken — not chicken with ice water.”

Fans of air-chilled chicken, which carries a retail price close to that of organic chicken, tout its top selling points: safety and flavor, along with texture.

Because air-chilled chickens are handled separately, rather than placed together into a large vat of ice water, proponents believe these chickens are apt to harbor less bacteria from cross-contamination. Studies, however, have not always concurred.

Supporters also believe air-chilled poultry tastes more “chickeny.” Because air-chilled chicken isn’t ever submerged in water, it absorbs less liquid, which fans say leaves the real taste of the chicken undiluted.

In comparison, studies have shown that water-chilled chicken sucks up anywhere from 2 to 12 percent of its weight on average in added moisture. And most of that ends up in the skin, McGee says, making it much more difficult to achieve a crisp bird when cooking.

I found that to be the case when I roasted a Fulton Valley Farms organic chicken side by side with a Field to Family air-chilled chicken. Both chickens were raised on similar diets by the same group of Central Valley family ranchers.

Uncooked, the Fulton Valley chicken looked glossier and plumper, while the air-chilled had a more matte appearance with tighter skin. After roasting, both birds emerged juicy. But the air-chilled had much crisper skin and firmer flesh.

As for taste, it was a close call. The air-chilled might have had an iota more flavor, but I knew ahead of time which bird was which. My husband, who tasted them blind, thought both chickens were equally flavorful.

When it comes to chicken in this country, our appetite has been relentless. Per capita consumption has been growing steadily since 1970. In 2006, according to the U.S. Department of Agriculture, the average person consumed 88.2 pounds of chicken.

Of about 200 chicken processing plants in the United States, only a handful use the air-chill method, according to Richard Lobb, spokesman for the Washington-based National Chicken Council, a trade group for the nation’s largest chicken companies.

MBA Smart Chicken of Nebraska became the first in the country to do so in 1998. Pitman Farms of Fresno became the first on the West Coast two years ago, when it debuted its “Mary’s Air-Chilled” chicken.

Today, about 50 percent of all chickens raised and processed by Pitman Farms are air-chilled, according to co-owner Mary Pitman, whose family spent seven figures to build its air-chilling facility.

“It’s the new wave,” she says. “There’s just been a huge demand by retailers. They all want to sell something that’s different.”

After a chicken is slaughtered, the USDA requires that the carcass temperature be lowered within four hours to at least 40 degrees to retard the growth of bacteria. For the majority of chicken in this country, that means water chilling. The birds are put into a large communal vat of chlorinated ice water to bring down their body temperature — about an hourlong process.

In contrast, air-chilling takes about three hours. After the chickens are slaughtered, and sprayed with chlorinated water inside and out, they are whisked one by one along a mile or more of track through chambers in which they are misted with cold air.

“I don’t think air-chilled chickens will ever be the standard,” says food scientist McGee. “But I’m sure consumers who are aware of the difference will gravitate toward them. They are just so much better.”DECIPHERING POULTRY LABELS

Fresh poultry: Internal temperature has not been below 26 degrees.

Frozen poultry: Internal temperature is 0 degrees or lower.

Natural: Contains no artificial ingredients or added color and is only minimally processed (a process that does not fundamentally alter the raw product). It has nothing to do with how the chickens were raised.

No hormones: Hormones are not allowed in raising hogs or poultry. Therefore, the claim “no hormones added” cannot be used on the labels of pork or poultry unless it is followed by a statement that says “Federal regulations prohibit the use of hormones.”

No antibiotics: The term “no antibiotics added” may be used on labels for meat or poultry products if the producer documents that the animals were raised without antibiotics.

Organic: Fed organic feed, which may not contain animal or poultry slaughter byproducts. Must have access to outdoors. No antibiotics.