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We’ve all had that magical restaurant moment: savoring an obscenely flavorful piece of meat, one so tender you could cut it with a butter knife. At home, however, we sometimes have to slice through the same cut (though this time bland) with a saw. What’s going on?
It all comes down to time.
The Backstory
You’ve all seen the label: dry-aged beef. It seems to be everywhere these days—from specially refrigerated shelves at the butcher store to the menu at fancy steakhouses. It’s more expensive. It’s more tender. It tastes better. But why?
Aging is a technique used by many restaurants on primal cuts of beef in order to create more tender, flavorful meat. To age beef, it is allowed to sit undisturbed in a humid refrigerator ranging between 32 and 40 degrees for up to 30 days. Yes, that sounds like a long time. But a lot happens during those days. A significant portion of moisture is lost and the muscle proteins begin to break down. But most important is the activity of enzymes.
Enzymes are a type of protein. One of their functions in living animals is the turnover and processing of other proteins around them. In meat, these enzymes continue to catalyze change. Here, there are two enzymes at work: calpains and cathepsins. They are both important. Calpains break down the proteins that hold the muscle fibers in place. Cathepsins break apart a wider range of proteins and can even weaken the collagen in the muscles’ connective tissue. Both have the ability to impart a meatier, umami taste and to tenderize.
The activity of these enzymes depends entirely on temperature. They are active when held between 32 and 40 degrees, but move slowly, which is why dry-aged meat held in a refrigerator needs 30 days. The rate of activity increases, however, as the temperature rises—right until it reaches 122 degrees. That’s when everything comes to a halt.
In the test kitchen, we wondered if we could use this enzymatic activity to our advantage when cooking meat at home. If we roasted meat very slowly, purposely keeping the temperature below 122 degrees to encourage enzymatic activity for as long as possible, giving the enzymes leave to work overtime, would this in effect “age” the roast within a few hours? Associate Editor Dan Souza devised an experiment to test just that.
The Experiment
Dan began by cutting one two-rib standing beef rib roast into two equal steaks. He cooked one in a sous vide water bath held at 120 degrees for two whole days (48 hours). He cooked the second in the same bath—but just until its internal temperature hit 120 degrees, which took about 2 hours.
To determine the effects of enzyme activity below 122 degrees, he devised a stress test.
Dan cut ¼-inch-thick, 4-inch-long cross-grain slices from the same part of each steak and suspended each vertically, holding them up with tongs.
To the other end of the steak strips, he attached 2-pound weights.
And then he waited.
Well, he didn’t have to wait that long. When Dan hung the slice of meat that had cooked for 48 hours, it tore in half immediately, the weight plopping down onto the counter in a split second. The second steak, however, hung in there for a good 15 seconds, stubborn and intact.
What does this tell us? Well, for one, internal temperature isn’t the only factor in determining tenderness in meat. After all, Dan cooked both samples of meat to the exact same temperature; the only difference was the length of time he held them there. Held under 122 degrees (in this case, at 120), the enzymes present in the meat did their best work. In the 48-hour sample, the enzymes had much more time to work their magic, which is why the meat was so tender it fell apart immediately. The sample brought right up to temperature was much less tender because it didn’t have the benefit of that extra enzymatic activity.
Don’t get us wrong. We’re not saying that the home cook should spend two days gently bathing a steak for dinner. Even an hour of enzymatic activity makes a difference. We like to roast meat slowly and gently, giving the enzymes as much time as possible to do their work. This technique is best for cuts with little connective tissue, ones ideally cooked no further than medium.
MAKE IT NOW
Our recipe for Slow-Roasted Beef is free through October 15, 2012.
Got any meat questions? Leave 'em in the comments.
About the Author: Molly Birnbaum
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I have so many meat questions!! First off, how many days does McDonalds take to cook their hamburgers?
- Is 122F safe for sous vide cooking over long durations?
- In the “dry-aging at home” technique, you guys wrap the steak in cheesecloth – is this to simulate the humidity level of an aging fridge? Are there any other ways to do this without using cheesecloth covering?
I have a feeling I’m going to love this new segment.
Curious though, was there a flavor difference between the 2hour and 2day versions?
While the 2 day version was definitely more tender, is it so tender as to feel like mush in the mouth, or does it still retain enough satisfying chew?
Well, while you claimed that the “[enzymes] have the ability to impart a meatier, umami taste and to tenderize”, your test only confirmed the tenderization of meet, not improvement in flavor. Even that may be attributed to the conversion of collagen into gelatin, which can be achieved in temperatures well above 122º (traditional braises achieving it at around 200º for example), not due to the enzymes. My guess is that if you were to conduct the same test at 150º for 48 hours, you would achieve similar results (with the exception of the extra loss of juices, but maybe a gain in tenderness due to the extra conversion of collagen at a higher temperature). I believe your test was fundamentally flawed, and this is coming from a HUGE CI fan…
As a matter of fact, if you are claiming that 122º is the temperature in which enzymatic activity comes to a halt, a steak cooked at 123º degrees for 48 hours should have the exact same texture as the one cooked at 122º and just brought up to temperature. Why not test that? As far as taste goes, since hot food should not be kept under 130 (or is it 140?) for longer than 4 hours (Iused to think it was 2 hours), and therefore the 48 hours steak would be unsafe to be consumed, how about cooking one steak at the original 120º and another at 123º (or 125º, just to be safe) for 3 hours and blind taste them in order to prove that enzymatic activity will improve the taste if held below 122º? By the way, you should double check the temperature of your Sous Vide supreme with a second thermometer. I know mine is off by 2º according to my thermapen. I once tweeted CK asking him for a sous vide section in Cooks Illustrated, and I still think you are the guys to do it, there’s absolutely no reliable information out there regarding sous vide cooking, but this test could have been much more thorough.
First, I hope no one tried to eat the steak cooked for 48 hours at 120, pretty sure that is a prime temp for promoting the activity of dangerous bacteria as well as any enzymes.
Second, I completely agree that either this website or Cooks Illustrated needs to address and include Sous Vide on a systematic basis. Why not start with a couple articles and see how it goes? There are more and more great sous vide references out there with widespread appeal, Modernist Cuisine at Home, etc. While Sous Vide may sound a little fancy for the masses and the equipment is still a bit pricey, it is a versatile and effective technique that is ripe for the kind of comprehensive testing and clear instruction that are hallmarks of CI’s work.