A lot of people think that if a little aging is good, then a lot of aging is much better. That explains why the Chicago steakhouse Primehouse, to take just one example, serves a rib eye that's been dry-aged in its Himalayan salt-tiled aging room for 75 days. But is Primehouse right? Will a steak aged for 75 days be much better than one aged for seven?
Fortunately, this is the kind of question that fascinates meat scientists. They have even created a contraption called the Warner-Bratzler shear device that measures the tenderness of meat by applying weight to a blade. (The more weight needed to cut through meat, the less tender it is.) Here's what meat scientists have discovered about aging: most of the tenderizing takes place within the first seven to 10 days. According to Susan Duckett, a meat scientist at Clemson University, after the 14-day mark or so, the beef continues to tenderize, but at a vastly reduced rate.
So what? If the beef keeps on getting more tender, even marginally so, why not keep aging it until it achieves the consistency of room-temperature butter?
Because things like cattle genetics, stress, and the rate at which cows gain weight have a greater influence on tenderness than aging does. The tenderest steak I ate during my world-wide quest for steak was in Scotland, of all places, and came from a hairy long-horned grass-fed critter called a
Highland that was dry-aged for three weeks. The Kobe and Matsusaka beef I ate in Japan was superbly tender and was hardly aged by North American standards. And a cattleman I know in Ellensburg, Washington, ages his wonderfully supple beefalo steaks a grand total of six days.
There are also consequences to aging. For one thing, it is expensive. (That 75-day rib eye at Primehouse costs $67.) The fat, furthermore, has a tendency to oxidize. This is can be a particularly big problem with grass-fed beef, which contains much more alpha-linolenic acid than grain-fed beef. This tremendously unsaturated omega-3 fat—each molecule has three double bonds—is volatile, which means over time it is prone to reacting with other compounds and creating "rancid" off flavors. Part of the reason grass-fed beef has reputation for gamy, intense flavor, in fact, is because it is often aged for too long.
But even grain-fed beef, whose fat is more saturated and contains much less alpha-linolenic acid, isn't immune to the perils of oxidizing. It just takes a lot longer. Given enough time, however, a blue moldy fuzz will begin to appear on the exterior fat, imparting the meat with an unmistakable funk reminiscent of blue cheese.
Some people think this is a good thing. There are steak aficionados—and even a few big-name food writers—who will tell you a great steakhouse steak is supposed to taste funky. That probably says more about the flavorlessness of today's commodity beef than anything else.
For the record, steak is supposed to taste like beef, not Bleu d'Auvergne. Intense aging is best left to wine and cheese. A good steak needs just two or three weeks. Anything more than that, in my opinion, is an overpriced gimmick.