EVEN in kitchens where fresh is king, the freezer remains a handy tool. There’s no easier way to deal with a bounty of meat from a big-box store or a butchering class or a C.S.A. share, or the haul from a fishing trip, or the unpredictable sighting of partridge and other rare birds in the Chinese market. In my house, the freezer is essential for drawing out the enjoyment of the prime mail-order meats that my mother sends for my birthday, and that arrive rock-hard under a block of dry ice.
Less handy, however, is the thawing process, which often requires planning a day or more ahead of the cooking. Food thaws slowly in the refrigerator, especially when kept in its plastic packaging, which is the method recommended by purveyors and the Department of Agriculture to minimize bacterial growth and the loss of juices. Thawing in cold water, 40 degrees or below, is safe and much faster — water transfers heat far more efficiently than air — but it can still take hours. I’ve never had much luck with the defrost setting on microwave ovens, which can start to cook one part of the food while the rest is still frozen.
Now there’s good news for last-minute cooks. It turns out that we can thaw frozen steaks and other compact cuts in as little as 10 minutes, without compromising their quality, and with very little effort. All you need is hot water.
This information comes, surprisingly, from research sponsored by the Department of Agriculture, though the methods aren’t yet officially recommended. The studies have been published in the Journal of Food Science and in Food Control.
At the U.S.D.A. labs in Beltsville, Md., Janet S. Eastridge and Brian C. Bowker test-thawed more than 200 one-inch-thick beef strip loin steaks in three different groups: some in a refrigerator at 37 to 40 degrees Fahrenheit, some in a constantly circulating water bath at 68 degrees, and some in a water bath at 102 degrees.
Air-thawing in the refrigerator took 18 to 20 hours, while the room-temperature water bath thawed the steaks in about 20 minutes, and the hot-summer-day bath in 11 minutes. These water-bath times are so short that any bacterial growth would remain within safe limits.
The water-thawed steaks actually leaked less juice than the air-thawed steaks. The researchers grilled the steaks, too, and found that all the thawed steaks lost about 26 percent of their original weight once cooked, while never-frozen steaks lost 21 percent. The study found no significant differences in tenderness between slow- and quick-thawed steaks.
Eleven minutes is pretty quick, but Brian A. Nummer and colleagues at Utah State University in Logan shaved away another couple of minutes by heating the water bath to 140 degrees, the standard temperature of steam tables in food service kitchens.
The Utah State group found that chicken breasts about a half-inch thick thawed in a little more than 3 minutes, and inch-thick breasts in less than 9 minutes. Although 140-degree water would eventually cook the chicken to medium-rare, they saw no signs of cooking. The quick-thawed breasts did lose slightly more juice than the refrigerator-thawed breasts, but when the chicken was grilled and served, a panel of 18 tasters was unable to tell them apart. And based on their mathematical modeling, the researchers concluded that any bacterial growth would remain well within safe limits.
So there’s no downside to quick-thawing steaks, chops, fillets and other relatively thin cuts in warm water right before cooking. Large roasts are a different story. They take long enough to thaw that there may be time for significant bacterial growth on their surfaces. Prompt cooking might well eliminate that problem, but until this has been studied, it’s safest to continue thawing roasts in the refrigerator or in water under 40 degrees.
Quick-thawing is easy to adopt in the home kitchen. But don’t expect your thaw times to match the lab times I’ve quoted unless you have an immersion circulator or another method to keep the water in motion and at a constant temperature. If the water is still, a cold zone develops around the food and insulates it from the remaining warm water. And without infusions of hot water or heat from a burner, the icy food cools the water bath.
Unless I’m in a rush, I’m happy to let the thawing proceed more slowly on its own while I take care of other tasks. I fill a large pot with 125-degree water from the tap, immerse the plastic-wrapped meat, weigh it down with a slotted spoon to keep it under water and stir the water occasionally. The water temperature drops, but stays above 100 degrees for a half-hour or so, depending on how much food is thawing.
Last week, I thawed 2-inch-thick filets mignons in an hour, whole squab in 40 minutes, a 1-pound whole fish in 20 minutes, and 1 ¼-inch-thick salmon fillets in 15 minutes. Thawing times can vary, depending on the volume, temperature and movement of the water as well as the food’s thickness and how it’s wrapped. (A lot of plastic swaddling interferes with heat transfer. It’s best to remove it and place the food in a thin resealable plastic bag, partly immersing it to force the air out before zipping it shut.)
So when you scan your larder to improvise a quick meal, don’t forget to look in the freezer. The makings of the main course may be just minutes away.
June 8, 2011
Copyright 2011 The New York Times