Wow! I was reading the amazing set of books “Modernist Cuisine” by Nathan Myhrvold et al. and came across the suggestion (on page 3-78) to tenderize beef by boosting the activity of calpain and cathepsin enzymes in the meat through bringing the meat to temperatures of 39C/103F for calpains and 49C/120F for cathepsins. These are the same enzymes that are at work when meat is aged at refrigerator temperatures (both for dry ageing and for ageing in vacuum), but much faster and (compared to dry ageing) without drying the meat. Although it is described as a strategy to improve tenderness, it is not repeated in the “best bets for cooking meats sous vide” on pages 3-96 and 3-109.
I was intrigued about this enzymatic tenderization and decided to test it with a rib steak with some nice marbling that I had picked up. The steak was about 1/2 inch (12 mm) thick.
I cut the steak in half to cook one half in the normal way (only at 55C/131F) and the other half with the ‘warm ageing’ (my name for it) method. Since rib steak consists of different muscle groups with different tenderness to start with, I planned to compare the pieces next to the cut I had made. I seasons the steak with salt and freshly ground black pepper.
Then I seared both pieces briefly (30 seconds per side) in a hot frying pan with a mixture of butter and olive oil. This step is for adding a bit of flavor, but especially to kill any contamination on the surface of the meat. This is more important than usual, since half of the steak is going to be kept in temperatures that are not only good for enzymes but also good for bacteria.
I let the steaks cool down a bit on a plate.
Meanwhile, I sautéed a chopped shallot, a chopped clove of garlic, some thyme sprigs and a bay leaf in the remaining fat.
When the shallot was golden, I added some beef stock and let this simmer for a bit. (To make delicious red wine sauce, add red wine first and add beef stock after half the wine has evaporated.) After simmering to the desired thickness, I sieved the sauce to serve with the steak later.
When the steaks had cooled enough, I sealed them into individual pouches. So far, both halves have been treated exactly the same.
But now for the different treatment. One half was kept in the fridge, while the other half was first ‘cooked’ sous-vide for an hour at 39C/103F and then I increased the temperature setting to 49C/120F and kept it for another hour. Then I added the other pouch that had been kept in the fridge, and increased the setting to 55C/131F. Then I cooked for 2,5 hours to bring it to medium-rare/pink and pasteurize the meat for additional safety.
This is how the meat came out, with the ‘warm aged’ steak on the right-hand side. It seems that the ‘warm aged’ lost slightly more juicy, but it was not possible to taste any difference in that respect.
I took the steaks out of the pouches and added the juicy from the pouches to the sauce that was made earlier. I dried the steaks with paper towels, coated them with a thin layer of olive oil and gave them a brief (less than 30 seconds per side) sear on a very hot griddle. I then served them on hot plates with the sauce.
There was visually no difference, but the ‘warm aged’ steak was much more tender than the conventional sous-vide (that wasn’t bad either). I was pleasantly surprised by this difference and will from now on cook beef this way if I have the chance (since it does take two additional steps compared to the conventional way). To think this steak had only cost 4 euros, I don’t think I have ever tasted a steak that was so tender, so juicy and so tasty.
I suspect that this treatment will allow for shorter cooking times for tougher meat and thus make those more juicy as well, so more experiments to follow!