Dry Aging – The Science and the Alchemy

Dry aging is all the rage right now – and for good reason.  The process can take an already excellent piece of meat and turn it into something truly sublime (it can also make crappy meat taste significantly better, but we won’t talk about the heathens who engage in that practice).  Dry aging is equal parts science and art; you need to be able to closely monitor and control your airflow, temperature, and humidity – but you also need to have the intuition to pull an aging primal at just the right time, and to be able to spot problems before they occur.  Done right, a properly stored cut can be aged for 60, 90, even 120 days – each day longer it hangs out the flavor evolves and deepens that much further.

When an animal is alive, its individual cells are supplied with oxygen and nutrients by the flow of blood.  When it’s slaughtered that process is done-zo.  Within minutes after death myosin and actin proteins – the ones responsible for muscle contraction – are deprived of their sweet sweet ATP (ATP being a triphosphate coenzyme that transports energy to other molecules) and begin to bond to one another.  This new protein, called actomyosin because molecular scientists have no imagination, locks the muscles into place for for a period of time until enzymatic action begins to break down the actomyosin, among other proteins.

The process described in that intensely boring paragraph is important to understand when looking at the dry aging process.  Basically, for any meat to be palatable after slaughter it needs to finish the rigor mortis process – something that doesn’t occur until the ph has dropped enough for enzymatic activity to really crank up its work denaturing proteins in the meat.  In short, in order for meat to taste good at all, it has to undergo the beginning stages of decomposition.  Dry aging meat is basically the practice of seeing just how far you can take that decomposition and still end up with a sellable piece of meat at the end.

The 120’s finishing up. The rib on the right ended up getting culled at about 90 days due to some fuzzy mold.

In order to dry age meat properly several parameters need to be maintained.  Cleanliness is essential in all manner of meat production, but here it’s paramount.  If your dry aging cooler isn’t surgically clean, you invite all sorts of bad bacteria, molds, and fungi into the mix. The only thing you want to be decomposing your meat are enzymes already present in it at the time of slaughter – benign molds and yeasts will inevitably find a home on the outside of the aging cut, but what you don’t want is an aggressively pathogenic culture going nuts on the surface of your meat.

Once you’ve got yourself a clean room, maintaining an appropriate temperature, airflow, and humidity level are key.  The cooler should be as close to 40 degrees as possible to allow the enzymes a warm-ish temperature to do their work – too much colder and the process slows down, and any warmer and suddenly the USDA “wants to talk”.  Humidity is held at between 70 and 80 precent; any lower and the meat will dry out too fast causing a hard crust to form which keeps moisture from escaping which causes the meat to go bad from the inside, any higher and the surface of the meat will remain wet which invites all sorts of bad guys to the party.  Maintaining constant airflow inside the cooler, and around all sides of the aging meat will prevent microclimates of humidity or temperature within which problems could develop.

Large scale aging operation. It smelled a-maze-ing
There’s one more factor to consider when discussing dry aging meat, and that’s the waste that’s generated.  Most people have probably noticed that dry-aged beef is considerably more expensive than it’s less aged counterparts, and that cost is almost solely the result of the waste inherent in the process.  Consider for a moment the economics of running a butcher shop:  Meat comes in the door at a price paid by weight, and the longer meat hangs out losing water to evaporation the less you now have to sell by weight.  Add to this the trimming off of the hard outer crust that develops as a primal ages, and the total loss involved in going from a fresh whole primal into a dry aged piece of awesomeness can be upwards of 30%.

Bandsaw-eyed view of the trimming process on a dry aged cut

So why do it?  Setting up and maintaining a cooler for dry aging is a pain in the ass, and the process is inherently heinously expensive – and I haven’t even touched on how much space it takes up and how difficult is becomes to maintain an inventory of costly items that won’t see the light of day of months.  In this, as in so much in life, the answer lies with the outcome.  All the hassle in the world becomes worth it when you finally trim down that well aged ribeye or strip, cut a steak and cook it up.  The water loss concentrates the intense beefy flavor and the enzymatic action creates all sorts of cool, deep flavors you wouldn’t expect from a piece of beef.  A good dry aged steak tastes not just super-beefy but also earthy and nutty with notes of blue cheese, mushrooms, and fresh baked bread. 

Tasting the various vintages. That day did not suck.
Just recently we pulled two ribeyes we had aging for 120 days (ended up being 124 but who’s counting).  After tons of painful trimming we were left with cuts of meat barely half the size of the originals that went in before Christmas.  The meat was deeply red, almost purple, and the taste unfreakingbelievable:  the fat smelled and tasted like buttered popcorn, and there were serious overtones of fruit.  I’m not kidding about that, more than one taster sheepishly asked “do you taste bananas?”  At the end of the day, to be able to put in place a process which yields such a unique end product is worth all the hassle in the world.

Finished product of that guy from up top. You can get a pretty good sense of the loss involved. The taste was out of this world.

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2 Replies to “Dry Aging – The Science and the Alchemy

    1. Most places age at between 36-40 F, since the USDA frowns on anything higher, and much lower is harder to maintain. I’ve been in some dry aging rooms in bigger facilities that go as low as 32.

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