CHAPTER 4

Dry Aging

The term “old meat” does not sound appetizing. But “dry-aged meat”? Well, that’s different. Now we’re in the realm of finely aged wine or a cheese served at the peak of ripeness.

No bigger trend exists in steak these days than dry aging. What used to be a rare, dark art has now become a mainstream dark art. What used to be a rumored delicacy and difficult-to-find product has become popular—and by consequence less difficult to find. And its popularity is no surprise. When you can transform an ordinary, delicious piece of steak into something that retains all original deliciousness but becomes even more tender, more complex, more savory, why wouldn’t you do it?

Aaron had his eyes opened to the wonders of dry-aged steak a few years ago at John Tesar’s Dallas restaurant Knife (see this page). Tesar gave Aaron a tasting that ranged from a 45-day steak all the way to over 200 days. Man, that was some beefy, beefy beef. He’d never had anything like it. Some of the older stuff was almost too funky and intense, but the midrange had just the right amount of gaminess. Jordan’s first memorable encounter came in Spain, where a 120-day dry-aged rib cut blew him away (see this page). Afterward, he had to find more beef like that. Years later, he can still remember the taste.

Because finding great dry-aged beef isn’t always easy, in this chapter, we’re going to tell you exactly how and why it works and how to do it. Neither of us had any experience aging steak before writing this book, but lots of conversation and advice from friends showed that it’s definitely something you can do at home. But before we get into that, we want to offer a few words on the differences between “old meat” and dry-aged majesty from someone who knows.

“I inherited a dry-age program at this facility from the people we bought it from,” says John Kosmidis, chief operating officer of Prime Foods Distributor, an important New York–based beef supplier to such esteemed steak houses as the high-end chain Smith & Wollensky. “Our predecessors had built a new establishment for dry aging with all the modern tools. But although they had a successful business and were highly regarded for their dry-age program, when we took over, I and my partners hated it. We thought the beef was terrible. We would look at each other and say, ‘Is everyone here brainwashed?’ ”

Kosmidis and his partners realized the answer was yes. “The brainwashing had gone up the chain from the producers to the processors to the further processors to Michelin-starred chefs to the media to the end consumer,” he says. “Everybody accepted something that if found in any other product would get you fired. But if you put it [spoilage] on the beef, it was prime dry-aged product. We thought that was so wrong.”

What Kosmidis is describing happened several years ago, when he and his partners founded the business. But it also describes something about dry-aged beef. If it doesn’t taste good to you, something is probably wrong. The tolerance for dry-aged chicanery in this world is great, as beef can get weird if it’s not properly aged. People might eat it anyway, find it off or too funky, and then say they don’t like dry-aged beef. Kosmidis sees this as the result of bad and irresponsible practices. “Other packers post photos of their dry-aging rooms [on social media], and we just shake our heads,” says Kosmidis. “They have meat piled up on meat, on racks that obviously haven’t been cleaned or moved in years, [and] there’s no air circulation. If you have mold growing because of bad conditions, your beef will be different colors. It can have purple, yellow, green, peach fuzz and hair. It’s not aging. It’s rotting.”

Kosmidis et al. decided to fix the situation. But for the art of dry aging, there’s no manual, no textbook, not even any real experts or scientists.
You can’t just hire a dry-aging wizard from the Internet to come in and fix your program. You have to start from the ground up. Over the next few years, the group revamped their procedure time and time again, spending millions in the process. They learned they had to pay attention not only to their aging conditions but also to their suppliers: how the meat was brought to them (full carcass or Cryovaced), how it was fabricated, how long since its slaughter date. They learned they had to pay attention to their refrigerated rooms: how much new meat was going into the same room as meat that had been there for a week or two. They had to clean. They had to have air circulation and rotate the meats. “It was the school of hard knocks,” Kosmidis says. “Trial and error. We took notes. We learned from our mistakes and paid for all of them.” But today, their steaks set the standard for dry-aged perfection.

APL

1680 Vine Street
Los Angeles, California
tel: (323) 416-1280 • aplrestaurant.com

Nothing made us happier than the 2018 opening of Adam Perry Lang’s long-awaited, long-toiled-over Hollywood steak house APL. No other accomplished American chef has ever been as associated with steak as Lang. Along with a Michelin three-star background at Guy Savoy in Paris and Daniel in New York and some respectable barbecue chops (Aaron has made custom smokers for him), Adam has serious steak credentials. More than anyone, he’s responsible for the surge of dry aging across the country, an art form he mastered at programs he created at Robert’s in New York and Carnevino in Las Vegas.

His beautiful new restaurant at the corner of Hollywood and Vine fulfills the dream of doing it for himself. The achievement here is purity: incredible steaks, done simply and perfectly. To that end, Lang is involved in every step of the process. He built a one-thousand-square-foot dry-aging room under the restaurant and tracks all of the meat himself. Everything is butchered on the premises (at the time of writing, by Lang himself) and cooked in a high-powered broiler. Every aspect of the experience has been considered, down to the steak knives, which Lang makes himself, having learned to forge and shape steel for this purpose (the knives are listed at nine hundred fifty dollars on the menu, the lowest cost of a felony in California; he’s serious about people not stealing them).

The menu is impressively simple: dry-aged steaks with a couple of sauces, as well as some classic sides, a lovely fish selection, a few pastas, and some starters. It’s rather minimalist, putting all of the focus back on the quality of the meat, which is impressive. The aging is done just long enough to create that savory, funky bite, but never gets in the way of the carefully sourced, deeply beefy steak.

KNIFE

5300 E. Mockingbird Lane
Dallas, Texas
tel: (214) 443-9339 • knifedallas.com

In his previous incarnation at Spoon, chef John Tesar was known for fish. That makes his reinvention as a master of meat all the more remarkable, especially because in no time his steak became some of the very best in the country. Tesar is known as a skilled technician who can cook anything, so his touch with simple, dumb steak is impressive. Here, it’s really the quality of the beef he chooses and the flavors he coaxes out of his dry-aging room that make eating steak at Knife worth a diversion.

The lengthy, diverse menu is well executed across the board (don’t skip the bacon-crusted bone marrow and caviar), but the steak menu—divided into New School, Old School, and Exotic—is the place to mine. The New School category lists such butcher’s cuts as the flat iron, culotte (sirloin cap), and skirt, all grilled over red oak. These all come from 44 Farms, an Angus ranch between Dallas and Austin that serves as Tesar’s main supplier and muse. Old School cuts include ribeye, filet mignon, and such. The Exotic menu comes from the dry-aging room and features 240-day and 110-day steaks, among others. Tesar has become known for pushing the dry aging to new distances, and sometimes he’ll have the odd 360-day pieces back there. Meat sources in the aging cellar also include HeartBrand and Creekstone. A variety of sauces—béarnaise, au poivre, Bordelaise, chimichurri, and salsa verde—are available on request.

Nowadays, Prime Foods keeps something like seven thousand subprimals of beef in its massive aging program. To be that large and precise is an achievement, and the lessons are well learned. And it turns out that all of the professionals who are dry aging meat for sale to customers or at their restaurants voiced the same refrain as Kosmidis: you have to learn by doing.

“We’re still learning as we go along,” says Bryan Flannery, who runs the famed Flannery Beef with his daughter, Katie, in Northern California (see this page). “We’ve got a system we like right now, but it’s changed over the years as we’ve grown and changed and learned more about the aging process.” For the Flannerys, getting enough air movement and making sure it was reaching every corner of their dry-aging room was key.

“You’ve got to figure out what works for you,” adds chef Adam Perry Lang, the reigning king of restaurant dry aging, from the vast room underneath his new APL Restaurant in Hollywood (see this page). Lang can largely be credited for popularizing (or repopularizing—after all, hanging beef for tenderization has been around for centuries) the dry-aging trend, as he’s done in New York, Las Vegas, and now at APL, his signature, personal spot. “There’s no manual for this. No teacher,” he continues. “But when you determine what you like in an aged piece of beef, it just takes time and experimentation to learn how to make it happen.”

That’s true in the restaurant and commercial realm, but it’s also possible in the home. It’s an undertaking, to be sure, but if you’re a serious and passionate steak lover with a little extra room in your place, it might be worthwhile.

What Is Dry Aging?

Dry aging is a complex but natural process that’s essentially an early-stage degradation of meat in which chemical processes alter its fundamental nature, making it more tender and more flavorful. As great food scientist and writer Harold McGee wrote in an essay in the bygone food journal Lucky Peach (issue #2), raw meats don’t have much flavor in their natural state, which is why we cook, season, and transform them.

“But sometimes we can get our food to make itself more delicious,” he says, “by treating it in a way that creates favorable conditions for the enzymes that are already in the food to work together in a certain fashion. Enzymes are molecules that exist in foods—and in microbes intimately involved with food—that can transform those basic, bland building blocks. They’re nanocooks—the true molecular cooks. Dry aging, ripening, and fermentation are all processes that take advantage of enzymes to make foods delicious before cooking.”

Every meat ages, but none quite as well as beef. As Modernist Cuisine, the incredible multivolume tome on the science of cooking, explains, “For reasons having to do with the relative activity of enzymes in different muscle-fiber types, red meat generally matures more slowly than white meat. Large animals require more time than smaller animals. And meat from younger animals ages faster than the meat of their more mature kin.” Fish see almost no benefit from aging, chickens for only a handful of days, and pork and lamb for a week or so. But beef? Beef needs two or three weeks to tenderize properly. Flavor development usually starts at anywhere from twenty-eight to forty-five days and can be taken into the hundreds of days.

This process has been around for centuries and likely longer, as there’s a thin line between intentionally aging meat and just trying to keep it from spoiling until your clan can finish it all. Of course, people have known how to preserve meat with smoke and salt for tens of thousands of years. But in the nineteenth century, McGee writes, beef and lamb would be hung at room temperature until the exterior flesh actually rotted. This result was desirable, probably because of the gains in tenderization and flavor, but also for matters of practicality, as the lack of refrigeration meant that a side of beef simply aged until it was fully consumed. Of course, we don’t desire rot today, but by controlling the simple variables of time, temperature, humidity, and airflow, we can guide the aging process to transform meat into something truly stupendous.

So what’s going on here? After slaughter, naturally occurring enzymes in the meat go to work. When the animal was alive, those enzymes were controlled by the living cells. But after the cells die, the enzymes are uninhibited and go to work on other compounds in the organism. They break down larger, flavorless molecules and chop them into smaller bits we can taste. In particular, they start to chop up fats, proteins, and a carbohydrate called glycogen into sugars, amino acids, and fatty acids. One of those amino acids rendered is glutamate, aka umami. And umami is, well, everything—or at least a primary reason savory things are so delicious.

Dry aging also forces beef to lose moisture. It’s not much but significant, as the remaining juices and tissue become more concentrated. Evaporation further concentrates the newly created enzymatic sugars and umami-boosting protein compounds. It makes beef beefier and, on cooking, creates even greater Maillardian cascades (remember, Maillard is the set of reactions that occur when the surface of the meat is browned during cooking). It’s an orgy of flavor, thanks to microbes that have been let off the leash.

WET AGING? MEH…

Inevitably, all the talk of dry aging brings up the topic of wet aging. This is when beef is Cryovaced and kept in the plastic bag for a few weeks, sitting in its own juices. Some people claim it is not only as effective but also more efficient than dry aging. After all, if it’s the enzymes that are acting, can’t they do so in a bag without any of the moisture loss that occurs during dry aging? The answer is yes, and it turns out that wet aging in a sealed bag does yield the same gains in tenderizing after about fourteen days. However, there appear to be no attendant flavor gains. In fact, after more than about four weeks maximum, research has shown tasters find wet-aged meat to be “flat” and “metallic.” Indeed, dry aging in a windblown cellar seems vaguely healthful. Who would want to be smothered in a wet plastic bag for weeks?

The other great benefit of aging is tenderization. A couple of enzymes called calpains and cathepsins sever the bonds in certain proteins, weakening connective tissues and reducing pressure, resulting in more tender, silky meat that’s also juicier because the relaxed meat has squeezed out less moisture during cooking. It’s a win, win, win—more flavorful, more complex, more tender.

The Challenges of Aging Beef

So if aging beef is so great, why isn’t everyone doing it all the time? There are a number of factors. On the commercial scale, dry aging takes time. And time equals money. If you have to lay out a lot of cash for beef you’re not going to sell for weeks or months, you’re taking on a big negative on your books for a significant amount of time, not to mention running an aging cellar requires space (additional rent), climate control (higher bills), and attendance (more labor costs). There’s also risk. What if something goes wrong? It could mean tens of thousands of dollars or more in losses. As long as people aren’t demanding it, as long as they’re satisfied with a simple, conventional unaged steak, why bother?

For the home dry ager—which you could become—the challenges are analogous. You need room for an extra refrigerator and to be able to afford the bills of running it full time. You need humidity gauges and wind-force producers to have the confidence that the meat is not going bad on you. You need to have a source where you can buy a large subprimal of meat. And most of all, you need patience.

How and Why to Age Beef at Home

Despite all the previous talk about the dry-aging school of hard knocks, it’s not that hard to age beef at home. And indeed, if you’re a steak lover, eat it regularly, and have a spacious abode, all the reasons in the world implore you to do this. After all, in most places, it’s difficult if not impossible to buy dry-aged meat to cook at home. Restaurants may have it, but they don’t sell at retail. And if you can find such places, dry-aged meat is expensive—not just the meat but also the shipping if it’s coming from a seller outside of your area. That said, dry aging beef is a commitment, so you have to really want it. On the other hand, as complicated and edgy as dry aging sounds—it’s really neither.

1. CREATE A DRY-AGING FRIDGE AND TRICK IT OUT

Beef aging can only occur in a highly controlled environment, which means temperature control is imperative. Maintaining a sufficiently low temperature without freezing is what decides the difference between aging and rotting. It’s the low temperature that keeps the spoilage bacteria at bay while allowing the enzymes to do their work. If there’s too much heat and moisture, the bacteria go crazy, and you’ve got a big hunk of rotting meat on your hands. A proper aging fridge should give you at least two feet across, though three feet is better, and about five feet of height, enough for two or three separate racks. The point of having a large enough fridge is that if you’re going to age large subprimals (big pieces of meat containing several steaks that you’ll slice off yourself), you need to have a couple going at any one time so you don’t run out and have to start from scratch and wait months every time you want an aged steak. Also, this is not a fridge into which you’re going to throw some extra bunches of celery and leftover risotto. If you want to be serious about dry aging, only beef goes in here.

Any sort of fridge will work as long as its reliable and has adjustable racks. Commercial refrigerators with glass doors are cool because you can see the meat transform (in slow motion) before your very eyes. But it’s certainly not necessary. Aaron bought a Traulsen two-door fridge from a restaurant supply store (he needed it anyway) and put it in his home garage (with plans to move it to a new facility later). But you don’t necessarily need restaurant-grade equipment. A good-quality used fridge purchased on craigslist will do the trick as long as it’s consistent and reliable. Whatever you buy, after you get it home, thoroughly scrub down the interior with water and bleach to disinfect it. Once the whole thing—top, bottom, sides, and racks—is wiped down, it’s fine to start decking it out.

2. BUY SOME FANS

Besides the proper-size fridge itself, you need to account for humidity and airflow. Of the two, airflow is the more important. Without constant air movement, the air stagnates and moisture hovers, creating a ripe environment for bacteria and mold to propagate. They love a moist and somewhat warm environment. As you dry out that exterior layer of beef, it forms a bulwark, preventing the interior from losing moisture. So air movement is a hero: it stifles bad bacterial growth and protects the juicy interior of the steak.

You’ll need at least one fan, but two or more are better. As Kosmidis said about his professional dry-aging cellar, “Every piece of meat is getting hit by air from at least eight different directions.” That’s overkill for the home setup, but good circulation is key, not unlike the dynamics inside a barbecue smoker. To get maximum air movement in a small space, Aaron set up several small but powerful fans to create an array. He bought a few small twelve-volt CPU cooling fans at a computer store, wired them in parallel, connected them to a power source, and then hung them from wires at the top of the refrigerator. But now he says that was overkill and he wouldn’t bother going to that much trouble again. It’s cheaper and easier just to get two or three small Vornado or other desk or room fans and point them from different directions at the meat. The result is a swirling chaos of air that ensures moisture is swept away. Professionals talk about necessary wind velocity in measurements of linear feet per second, but without getting so geeky, this setup has worked well for meat that’s been steadily aging for months.

3. HUMIDITY AND TEMPERATURE

Humidity is a concern in dry aging, though it is not as big a deal for the home dry ager as for the people working on a commercial scale. The crucial aspect of humidity is making sure it’s not too high. Too moist an environment and bacteria will grow, so drier is better. But the drier it is, the more moisture evaporates from the meat, causing the meat to lose weight. Indeed, after a standard forty-five to sixty days of dry aging, a rib rack of beef can lose up to 30 percent of its weight in water. So large meat packers—people who sell meat by the pound—typically like to keep the humidity as high as possible to retain water weight without courting microbes.

For those interested foremost in quality, however, that shouldn’t be a concern. Kosmidis says, “We experimented constantly. At first, we were at high humidity, around 80 percent. In the beginning, we accepted the thinking that if you’re dry aging, your first priority should not be to minimize your yield loss but to produce a proper product regardless of loss.”

The figures generally cited as necessary for maintaining a safe environment are 70 to 80 percent humidity. If you have a restaurant with a giant room full of aging meat with fresh, wet meat being introduced on a weekly basis, managing humidity to maintain sterile levels becomes more of a challenge. But in a typical refrigerator, staying below 80 percent humidity is not a problem.

Home refrigerators are programmed to be dry: to condense humidity and then dispose of the water periodically. This is because the frequent opening of a refrigerator door introduces humidity into the environment, which makes fridges less efficient because it takes more energy to cool humid air. That means if you have a fridge dedicated to meat aging and you’re rarely opening the door, it’s going to dry out in there, to the tune of humidity levels in the 30 percent range.

Very low humidity doesn’t appear to be a severe problem in aging meat. You might think that low humidity will cause the meat to eventually shrivel up and dry out, but luckily it doesn’t seem to work that way—at least not over the few weeks or months most people will age their meat. Rather, and amazingly, dry-aged meat is usually quite juicy. Scientists debate why this is so, but some have referred to the exterior drying of the meat as basically closing off the channels through which water contacts the air, sealing moisture in.

Temperature in a refrigerator generally takes care of itself. Standard temperatures for aging beef run between 34°F and 39°F. This is generally easy to maintain, especially if you keep the door closed all the time.

Aaron added a humidifier to keep his dry-aging fridge from getting too dry and set the temperature at 38°F. He also added a basic sensor, easily purchased at any hardware store, to monitor the humidity and temperature. After just a few days, the rig stabilized in a range at which it seems comfortable: 36°F to 38°F and 60 to 64 percent humidity. The beef happily aged for months.

4. BUY SOME BIG HUNKS OF MEAT

Aging individual steaks doesn’t work. Sure, you can let them sit out in the refrigerator for a few days, but these loners will dry out before any of the significant chemical changes from aging take place. If you left that steak in the fridge for, say, twenty-eight days, by the time you trimmed off the rock-hard, dried outer shell, you’d have nothing left to cook. Thus, aging has to be done on bigger pieces, large enough that you can trim off that crusty pellicle and still have plenty of delicious, juicy meat. So what cuts, er, make the cut?

First of all, you want well-marbled cuts with bones and fat caps, so this factors out most steak cuts. Pieces like skirt, flank, bavette, and even tenderloin are all too small and lack bones and much exterior fat. Also, you want high-quality meat that has been handled well since it was fabricated (the meat industry’s term for cut). It should be fresh, pristine meat that hasn’t been punctured or opened up in any way. This all ensures the integrity of the interior of the meat, as the exterior pellicle that develops during dry aging will all be trimmed away.

Bones and fat caps are essential for a few reasons. First and foremost is that they lie on the exterior and protect the meat. As the enzymatic aging occurs within the meat, these components are slowing the loss of moisture from the exterior. But there’s also a flavor component to the fat.

A good deal of that “funk” people love about dry-aged meat, that somewhat gamy, mushroomy, cheesy, nutty aroma that layers on the irresistible umami, is dependent on fat. As Modernist Cuisine notes, “The oxidation of fat and other susceptible molecules also contributes to the aroma of dry-aged meat. In the case of meats high in saturated fats, beef being the prime example, the aroma can be pleasantly nutty, with mild cheesy notes. Indeed, it is the combination of concentration and oxidation that further enhances the flavor of meat as it continues to dry age beyond the point at which enzymatic tenderization has come to a halt.”

The upshot of this is that tenderizing is accomplished within about two weeks. Further aging is for flavor, and a healthy fat cap and lots of marbling provide that. The most profound expressions of the aged flavor occur on the perimeter of the steak; the interior will taste less intense. Perhaps this is because the interior meat isn’t exposed to oxygen and thus the fat doesn’t oxidize. But it does mean that as much of the outer part of the steak as possible should be left on while cooking. You may take off most of the fat cap, but consider leaving on some of the fatty scraps. And definitely keep the bone. All of these parts—especially the rib-cap muscle, or spinalis dorsi, which takes on the most intense aged flavor of any part—will contribute flavor and aroma to the final, delicious steak.

Long bone 103 rib

So with their processing numbers and a brief description, here are the large cuts that offer maximum efficiency, return, and character for dry aging.

When it comes to sourcing your meat this should be obvious: try not to buy anything that’s been previously frozen. If you have the ability to procure primals and subprimals that haven’t been Cryovaced, do that, as the freshness of the beef is an asset. However, if the meat’s been in plastic for just a short time, it’s okay. What you want to avoid is meat that has wet aged for more than a week or so, as the degradation that occurred inside the plastic doesn’t translate well to the dry-aging environment. The meat will tend to dry out without much flavor development. The way to source these cuts is by talking to a butcher at a specialized shop or a good grocery store. These large cuts won’t be offered at the counter, but the butcher should be happy to get them for you from his or her supplier or at least connect you directly to the supplier.

5. STORE YOUR MEAT

When you put the beef in the dry-aging refrigerator, make sure it sits on standard wire shelves (as in Metro shelves) that allow air to pass through them. Remember, the idea is for air to be blowing on all sides of the meat at all times. Make sure there’s five or six inches between cuts of meat, as the evaporating water needs some place to go and fresh air needs to circulate freely around the cuts. Every week or so, shift the angle or position of the meat just to even things out.

6. WAIT AND MONITOR YOUR PROGRESS

Okay, you have your fridge plugged in and chilling. You’ve set up an array of three or more fans and have cold air blowing like mad throughout the fridge. You’ve purchased your beef and placed it on one or more shelves in the fridge. What’s next? Now is the easy part: you just wait. But for how long?

How long you age your beef is entirely up to you. But here’s a handy guide to the general cutoffs. Remember, every animal is different, however, so every piece of meat is different. Also, differences in temperature and humidity can have a profound effect on the rate of these chemical transformations. There is no precise accounting for any of this. And even if you’re getting a piece of meat cut from a fresh carcass that has never seen the inside of a bag, the likelihood is that the meat is already at least a week old. Cooling, processing, and transportation all take a certain amount of time, so it’s almost surely not “fresh” meat that you’re getting.

In the first 14 days of aging, you’ll start to experience tenderization of the meat, but no flavor change. From 14 to 21 days, the meat will continue to tenderize, but that process should technically end around the three-week mark. From 21 to 28 days, you may get the first hint of an evolution of flavor, though not much. The advent of that dry-aging funk only starts to kick in after 28 days, when it should become noticeable the moment you open the fridge door and take a whiff. Flavor development will continue indefinitely and then becomes a matter of taste. At 45 days, you might get that telltale whiff of blue cheese that some people talk about, though in our experience, it’s more of a gamy, mushroomy quality. Many people consider 45 days of aging a sweet spot; some people think of it as just the beginning. It’s not unusual to find meat sellers taking steaks to 60, or even 90, days. You can expect quite a bit of funk after 90 days. And flavor keeps developing, albeit more slowly. Nowadays, chefs are taking aging to ever more distant extremes, up to 220 or 360 days—and sometimes up to 400 days. A butcher in Paris even sells vintage steaks that are over a decade old, though it sounds like he uses a special freezing technique (ice-cold air is blown at high velocity over the meat), so it’s not quite the same.

In general, you may have diminishing returns from aging more than 60 to 90 days, and we don’t recommend going beyond that. The meat will just dry out and become hard and crusty. You’ll have to cut the dried parts off, as they become basically petrified and harder to eat. Over time, that dried pellicle will simply increase and you’ll lose more and more meat. At 60 days you can have both great flavor and great tenderness.

7. FINISHING

Whew, you’ve made it to the end of your journey and successfully aged a large chunk of beef. It smells funky-delicious, and the exterior meat has dried and turned a glorious color of dark reddish brown. Now it’s time to slice off a couple of steaks to taste the results.

Pull the big piece from the fridge and set it on a clean cutting surface. Have a very sharp slicing knife handy. If there’s any bone like the chine (spine) bone on your piece, also have ready a saw—we recommend the twenty-two-inch Weston butcher saw—as you can’t slice through a heavy beef bone with a knife. Then decide how thick you want your steaks and slice them off cleanly. It’s all basic, no matter what subprimal you’re using. Just visualize the kind of steak you want and cut through the bone. Now, if there’s still a lot of meat left on the piece, it can be returned to the refrigerator to continue aging. Or you can just plan to consume the rest over the next week, keeping it in your kitchen fridge.

After you’ve got the steaks, you’ll want to clean them up a by removing the hardened exterior crust. Do this carefully, and not too generously, as you want to keep as much good meat and fat as possible. If you cut too deeply into the steaks, you’ll discover meat that’s as bright and fresh and red as you’d find in a grocery store meat counter. Instead of going that far, just remove the driest bits, as the rest cooks beautifully, softening in the pan (or on the coals) as the fat around it melts and wets it. These will be some of the tastiest, meatiest bites you’ll have.

DON’T SCRAP THOSE SCRAPS!

After you’ve trimmed your steaks, you’ll find a little pile of trimmings sitting on the cutting board. Given however many weeks you dedicated to aging the meat to perfection, don’t you dare throw those bits away. That’s valuable stuff right there! There are a number of things you can do with the scraps. For the fat, you can render it down into a liquid and baste or spray the meat with it during and after cooking, as you would with butter. This way, you’re simply dressing this delectable meat with some of its most flavorful bits. Any shards of meat bark you slice off can be saved along with the bones and turned into deep, savory, rich stock, which could then be reduced again to make an aged-beef demi-glace for aged beef.

LET’S GROW MOLD TOGETHER

You can’t talk dry aging without bringing up the subject of mold. A good cellar with great air movement and moderate humidity should grow little to no mold as the beef ages. However, for long periods, even at low temperatures and moderate humidity, some species of mold will eventually form on the exterior of the beef. Is it something to be afraid of?

In an email, Harold McGee agrees that the meat’s own enzymes are key, but microbes play a role, too. “I do think that the changes in flavor and texture are mainly due to the meat’s own chemistry,” he writes, “but there is evidence from dry-cured hams that surface microbes can affect the external muscles. What we easily see is the molds, but there are yeasts and bacteria in there as well, and apparently their Gemisch of enzymes can penetrate to some extent. Of course, hams are aged for months to years, so that effect may not be relevant to dry-aged beef.…I haven’t found any real research on this.”

The most common molds are harmless and even beneficial. As a 2016 paper published in the Journal of Animal Science Technology noted, several molds can appear on the surface. “Thamnidium, which is the most desirable, appears as pale gray patches called ‘whiskers’ on the fatty parts of aged beef. These organisms are important because their enzymes are able to penetrate into the meat. In fact, Thamnidium releases proteases and creates collagenolytic enzymes which break down the muscle and connective tissues. As a result, these actions bring about tenderness and taste in the dry-aged beef.”

In general, a little mold is natural and will get trimmed off before cooking. The dried crust of the meat protects the interior meat from mold-based spoilage. And beef will also usually be seared at a very high temperature for several minutes, making it difficult for any microbial life to survive. The mold in all the best dry-aging cellars we’ve seen has taken the shape of a sort of white film, similar to the mold you’ll find on the exterior of a salami. It always gets trimmed off and the interior meat is fine.

Exterior mold is not usually dangerous. But if there are openings in the meat into which surface microbes could have entered and found a moist environment, throw away that piece. Likewise, if the beef has developed slime or off-colored molds or any sort of bad aroma, throw it away.

To try to preempt the mold question, some people have taken to introducing a tried and proven mold at the beginning through innoculation. Adam Perry Lang brought out some aged meat to inoculate his Las Vegas dry-aging room at Carnevino and then again when he built APL, his palace in Los Angeles. John Tesar got some scraps from Adam to inoculate his dry-aging room at Knife. Even so, Tesar’s steaks taste different from Perry Lang’s, suggesting that the source of the meat is far more important than whatever culture grows on the outside. But even cellar mold can have a proud provenance. To do this for your home dry-aging fridge, simply find your favorite dry ager of steak and ask for some scraps and fat trimmings. Take those scraps and leave them in your own fridge for a couple of weeks, then toss them. If it works, you’ll have introduced a microbial culture that will thrive and take up residence. We didn’t do this for our first dry-aging runs and the beef was fine. Indeed, it didn’t develop much mold at all. But in future cycles, we’re going to inoculate. After all, better the mold you know than the mold you don’t.