You can occasionally buy aged beef from specialty butchers, or you can do it my favorite way: get three friends and head to a restaurant that specializes in dry aged beef and do an expensive comparison tasting.
Or make it yourself.
There are two types of aged beef, wet and dry. Both aging methods are designed to allow enzymes to tenderize the meat, but the methods are very different. A few hours after a steer is slaughtered, its muscles get stiff as rigor mortis sets in. This “green” beef is tough, dry, and not very tasty. It takes a few days for the muscles to relax and enzymes to kick in and begin to tenderize the meat. Enzymes are “nanocooks” in the words of food scientist Harold McGee, and they do what a professional cook does when cooking beef: they break down the proteins, amino acids, and other compounds, creating new compounds including glutamates, the source of the savoriness known as umami, which is the main flavor we look for when eating steak. As the beef ages, more interesting flavors emerge, and that is what the fuss is all about. But you can’t age beef by just throwing it in the fridge and waiting for it to get tender. Oxygen and bacteria can mess it up.
Before we dive deep into dry aging, here’s a brief explanation of wet aging, the technique used for most meat sold on the market. At the slaughterhouse, meat is usually packed in plastic “cryovac” bags that have had most of the oxygen removed. Meat rarely stays in the bag for more than 28 days. During that time, enzymes tenderize, but they have minimal impact on the taste of the meat. If you buy cryovacked meat, check the packing date and if you wish, you can store it in the fridge for up to 28 days from the bagging date. Don’t push it beyond that, though, and don’t try to bag meat yourself. If there are bacteria on the meat or in the air; if there is oxygen in the bag; or if there is a leak in the bag (and there most definitely can be any or all of these), things can go south in a hurry. But just leaving the cryovacked meat in the fridge until day 28 gives enzymes more time to do their work. Brisket cooks swear that wet aging up to 28 days makes a difference in the tenderness of this tough cut. If you try it, one word of caution: when you open a cryovac bag, the meat often smells odd. It is called the cryovac stink, and it usually dissipates within an hour.
Some Egyptian royals were so fond of dry aged beef they were buried with it (click here to read about some dry aged beef ribs buried with the couple that loved it sooooo much). During dry aging, the meat is stored in a sanitary room at 34 to 38°F and usually 70 to 80% humidity with brisk airflow for anywhere from 28 to 75 days. Dry aged beef is noticeably different tasting than fresh beef or wet aged beef. The longer it dry ages, the more complex it becomes. Some describe the taste as earthy, nutty, gamey, leathery, mushroomy, and cheesy. Some say it can even develop notes of prosciutto. Some people are addicted to it. Some just plain don’t like it. Before you decide to try dry aging at home, go to a restaurant and try several “ages” of beef. In the picture below, we see bone-in rib primals in the dry aging locker of David Burke’s Primehouse in Chicago (closed in 2017). From left to right, they range from 7 days to 20 days, 30 days, and 60 days.
Aging works especially well on beef and bison, less well on other meats. It is not a good idea for pork, since pork fat goes rancid rapidly. It is rare to find dry aged beef in grocery stores because most of them buy their meat in vacuum packed plastic bags. Some specialty butchers and high end restaurants offer dry aged beef. Only a few fancy steakhouses and upscale butchers have aging rooms. I have had aged beef often but a while ago I had the opportunity to do an aged steak tasting at David Burke’s with the chef at the time, Chef Rick Gresh. They buy all their Black Angus from the same farm, and the farmer raises and feeds the cattle the same way (see a small portion of the aging beef below). I brought members of my team, and together we tasted ribeyes aged 28, 45, 55, and 75 days.
All of the aged steaks were wonderful, but all very different. After 45 days, the flavor had changed so that it no longer tasted like beef as we know it. It was as if the meat came from a different animal. Many of the changes in taste occur in the fat rather than the muscle. As for the texture, beyond 45 days, I was unable to notice much difference in tenderness. My favorite was the 28 day steak because it had not yet gotten funky, but the flavors were concentrated and the meat was oh so tender. Others preferred the older meats, proving once again that taste is a matter of taste.
Will you like the taste of dry aged beef? The question is similar to: Which do you prefer, beef or lamb? Mayo or Miracle Whip? Smooth or chunky? It’s a personal preference. But there’s one way to find out. Find a steakhouse that ages beef and taste it.
Dry aging is sometimes called controlled rotting because enzymes, molds, bacteria, and oxygen go to work on the meat. The exterior of the muscle gets dark purple and a small amount of moisture evaporates, shrinking the meat about 5% (as Kenji Lopez-Alt explains, it is not the dramatic 20% shrinkage you may have heard about).
As water evaporates, flavors concentrate, so the meat tastes more meaty. While water evaporates, fat does not, so the ratio of muscle to marbling changes. The meat becomes fattier overall. The higher the fat ratio, the richer and juicier the meat feels in the mouth, proving once again that the juiciness sensation is caused by much more than the water content of the meat. Fat plays a significant role in juiciness.
Just before cooking dry aged beef, the outside crust is trimmed off, and the meat is sliced into steaks, so another 10 to 15% of the weight is lost. Can you see now why aged steaks are so expensive? The selling price is an additional $1 per aging day on top of the normal price. And that’s why it pays to age beef yourself at home. You pay only for the steak, not the aging (despite some loss in the total weight).
Alton Brown of Good Eats on the FoodNetwork likes the idea of aging single steaks and instructs us to “Wrap the steak in a single layer of paper towels and put on a cooling rack set inside a half sheet pan. Refrigerate 24 hours. Discard the paper towels, rewrap and return to the refrigerator, on the rack, for 3 days. Change the paper towels again if they become damp and stick to the steak. An hour before cooking, remove the steak from the refrigerator and remove the paper towels. Thirty minutes before cooking, sprinkle the steak on both sides with the kosher salt.” I have tried it and, although I usually agree with AB, it was a heckuva lotta work for very little improvement, and I’m not sure there was any improvement.
Ready to age some beef? First, select high quality meat, at least USDA choice or USDA prime, preferably tightly wrapped in a vacuum pack cryovac bag. Fresh meat is best, but if you have frozen, Chef Gresh says it is important that you defrost the meat slowly in the fridge, not under running water, to help preserve its integrity. Next, get the right cuts. You want to start with a prime rib roast that weighs 20 pounds. Or a strip loin. Or a sirloin. No tenderloin. It is already very tender, it is low fat, and it can get mushy with age. These are expensive meats, so don’t screw around or take shortcuts with the aging process. That’s a lotta meat. But what you don’t use right away after aging, you can freeze.
There are five variables that you must control: Quality of meat, temperature, airflow, days of aging, and to a lesser extent, humidity. Some people use their kitchen fridge for aging beef. I don’t recommend it. The door opens and closes, moist and warm air and microbes enter, and there are lingering smells in there that the meat will happily absorb. If there is any mold on the shelf from the time you spilled the milk or chicken juices or mold in the onion drawer, you likely will fail (remember: that meat is expensive!). It is best if you have a second fridge used just for aging meat. If you want to store some beer in there, OK, but make sure the bottles are clean. Make sure the fridge is clean. Turn it off, wipe it down with soapy water, rinse, and rinse once more with a bleach solution made with one tablespoon of 5% unscented liquid chlorine bleach per gallon of clean water. Then air it out to get rid of the chlorine smell. Some folks buy a small dorm refrigerator or a keg fridge and dedicate it to this purpose.
The fridge should be kept at 34 to 38°F. Any lower than 32°F and the enzymes will go on strike. Above 40°F spoilage microbes can grow. Even if you aren’t aging meat, your fridge should be set to 38°F max. It significantly reduces spoilage, even in comparison with 40°F. And, of course, you need a reliable thermometer. A dial thermometer is not reliable. Normally I recommend digital thermometers, but a liquid bulb thermometer is accurate enough for refrigerator temps.
Many experts believe humidity is critical with the ideal being 80 to 85%. Recent research says don’t sweat it. According to a 2008 technical paper on Aging Beef by Professor Jeff W. Savell, PhD, of Texas A&M, “There are no published studies that have compared the effects of different relative humidity levels on dry-aged beef, and it appears the studies in this area have used a relative humidity of approximately 80% with a considerable range around that number.”
Wash the outside of your sealed cryovac bag with soap and water before opening it. Then open it, drain off the liquid, and wearing gloves so you don’t contaminate the meat, rinse off the slime and then pat the meat very dry. Leave the fat and bones in place: they will reduce evaporation during the aging process. After aging, you will want to remove them. But for now, weigh the meat so you can calculate the weight loss.
Take a large pan wider and longer than the meat, and fill it with about 1/2″ of salt. It doesn’t matter what kind of salt. But salt is corrosive, so you do not want to use an aluminum pan. Stainless steel, glass, or porcelain pans are OK. The salt will absorb drips, moisture, and odors.
Put the meat on a wire rack, preferably stainless steel or coated with nickel or plastic, and place the racked meat on top of the pan above the salt. Don’t use a roasting rack, which holds the meat below the walls of the pan. You want ample airflow all around the meat. If you don’t have a suitable rack, you can put the meat on the (cleaned!) top rack of the fridge and put the salt pan on the rack below.
Ample airflow helps to move moisture away from the meat’s surface. Professor Greg Blonder, the AmazingRibs.com science advisor, uses a fan from a dead computer and runs the cord between the door gasket and the door jamb. I use this 5″ battery powered fan with an AC adapter. I thread the cord through the fridge door gasket on the hinge side and it does a fine job of keeping the air flowing and moving moisture off the meat. To help stabilize the fridge temp, put a few gallon jugs of water in fridge to chill. The cold jugs of water will help the fridge recover its temp after it has been opened and closed.
Some recipes call for wrapping the meat in cheesecloth, kitchen towels, or paper towels, and replacing them every day. The idea is that the wrapping pulls moisture to the surface and helps wick it away. Don’t bother with these shrouds. You want the meat fully exposed to dry air, not in contact with wet cloth.
The next step is the beauty of this technique: do nothing. Just let the meat age. And let it go for at least three weeks. Taste tests show minimal flavor changes in meat aged less than two weeks, but most people can taste subtle changes after three weeks. At about 28 days, flavor changes become more obvious. You can go longer, and you might want to push the envelope to see what age is your fave.
When you are ready to eat, there are two ways to go.
1) You can trim about 1/4” of the black crust and the bones off the entire slab. You’ll need a sharp stiff bladed knife for this because the meat has dehydrated and will feel hard. An electric knife works fine. Throw out the trim, and cut what’s left into steaks and roasts. Wrap everything in plastic. You can refrigerate the pieces you plan to eat within a day or three, and freeze the rest.
2) You can cut off only the amount you want to eat, trim that amount, and leave the rest of the slab to continue aging.
Now tuck in for a treat!
In recent years, a clever new product has come on the market, the UMAi Dry system. This company makes transparent bags in which you place meat and, with a vacuum sealer, draw out the air and seal the bag. The UMAi material is not a conventional plastic, as you can see here in a photo by Jaden Hair of SteamyKitchen.com. Moisture will not drip out, but it will evaporate out. Research by a team from Kansas State University and Sweden published in the journal Meat Science has shown that the bag’s permeability does not create an anaerobic environment, so dangerous botulism bacteria cannot grow, and other microbes are too large to enter the bag. For this reason, the manufacturer claims, “If you want to dry age cleanly and safely in any refrigerator or cooler, excellent air flow and the application of UMAi material is the combination most likely to give you excellent results.” As you can see, the process differs a bit from the old fashioned system where air and bacteria can contact the meat. Alas, not every vacuum sealer will work with the bags. The company sells its own sealers, and they are expensive. So is the bag material. I have not yet tested this product, but it’s worth exploring if you plan to age beef regularly at home.
It’s easiest to buy a small dorm-style fridge dedicated to the task of aging meat. Or you can invest $1,449 in the Steak Locker. It is temperature and humidity controlled with a carbon filter, a UV light to kill bacteria, and a glass door so you can watch your meat age. It even talks to your smartphone with readings of temp, humidity, and elapsed time. I have not tested it yet.
Another aging environment, the SteakAger, has been in development a long time through crowdfunding. I strongly recommend you wait until we have had a chance to test it. The basic model is a roughly 1 foot square plastic box that fits inside your fridge. On top, it displays temperature, humidity, and a day counter. There is a clear plastic front, a fan, and a UV light to kill bacteria. It is small with a capacity of only 22 pounds, but that could be the right size for fans of dry aging beef at home. They also sell a larger and more expensive refrigerated version that has a 40 pound capacity.
Published On: 5/27/2018 Last Modified: 4/20/2021