Sometimes looking for answers in the kitchen leads me to more questions than I started with.
I love it when that happens. Like with my most recent round of sous-vide testing on lamb legs. Specifically yogurt-marinated, grilled lamb legs. Last week, my wife grilled yogurt-marinated lamb for dinner... in our tiny New York apartment. The meal was delicious but when we woke up the next morning and the whole place still smelled like freshly grilled lamb (not so great over coffee!). I started to think, there must be a better way. My first thought was if I could precook the lamb, sous-vide, then it would only need a few minutes on the grill, thus reducing our post lamb grilling air freshener budget exponentially. It seemed simple enough — precook lamb, flash on grill for just moments, perfectly cooked lamb with minimal stink. Everybody wins.
Further, I thought, the lamb should come out more tender and flavorful. Besides enhancing flavor, the yogurt marinade helps tenderize the meat, and vacuum sealing the meat should help the marinade penetrate more deeply. And then to test the limits of tenderness, we set up one piece to marinate in buttermilk instead of yogurt to see if there was an effect on tenderness. And so we had four test groups: #1 — boneless lamb leg, yogurt marinade, cooked 62˚C 90 minutes #2 — boneless lamb leg, yogurt marinade, cooked 62˚C 45 minutes #3 — boneless lamb leg, buttermilk marinade, cooked 62˚C, 90 minutes #4 — boneless lamb leg, yogurt marinade, grilled to 140˚F All three pieces of meat that were cooked sous-vide went through the proper cook-chill process, then held for one day for tasting. For the taste test, the sous-vide meats were rewarmed in a 120˚F water bath before the bags were opened and placed on a very hot grill until the exterior was just browned, about 90 seconds per side. All meats were left to rest 5 minutes before slicing.
Well, the results were mixed. Opinions on which meat turned out best varied greatly, but after a bit of debate, a general consensus was reached. The most tender and well-cooked piece of meat was the one that was cooked sous-vide for 45 minutes — shorter cooking was better. However, the most flavorful piece of meat was the one that was only grill, no precooking. Which brought me back to the beginning and a possible error in the design of the test — the meat that was only grilled had over 24 hours to marinate before cooking while the sous vide meats were cooked immediately. So, was the grilled meat more flavorful because of its extended marinating time or does cooking completely on the grill produce a more flavorful piece of meat? Back to the drawing, er... cutting board.