Aged Meats

In order to evaluate the quality of meat, you must understand that, once the animal has been slaughtered, different reactions continue to take place in its tissues which modify their composition in ways that are important for the taste and texture of the meat.

After slaughter, the temperature of the animal starts to decrease gradually, the carcass stiffening into the well-known rigor mortis, best observed in birds that have just been shot during a hunting party. This happens because there is no more blood circulation to bring a supply of oxygen to the muscle cells. These cells now exist only on the energy they can still derive from their stored sugars (glycogen). As the carcass cools, the muscle fibers contract more and more as myosin and actin cross-link. With the help of enzymes, the glycogen present in the muscles fibers is degraded to a relatively large amount of lactic acid which accumulates in the meat, since there is no more blood circulation to remove it. This is why, if a steak or roast is cooked while the meat is still in rigor, it will have a tough texture and a noticeably acid taste when cooked rare. I experienced such meats during the war, since the only little bit of meat we had was sold as soon as slaughtered and we were too hungry to let it sit and lose its rigor.