It is known that after killing an animal, physical and chemical changes occur in its flesh, characterized by rigor mortis, and then relaxation (softening) of muscle fibers. As a result, the meat acquires a pronounced aroma and is easier to cook, that is, its nutritional and, consequently, food value increases. These changes in the muscle tissue of the carcass are called "ripening" ("aging") or "fermentation of the meat".
The meat of just killed animals is soft, juicy, well amenable to culinary processing, but its taste and aroma are inferior to mature meat. Fresh meat is elastic, oozing blood, easy to cut. A few hours after the slaughter of the animal, the process of rigor mortis begins, the meat becomes tough. In small animals, this happens in less than an hour, while a large animal stiffens within 6-10 hours. Such a product smells perceptibly of blood and, if you press on it with your finger, it springs, squeezes with effort, in the finished form, food from such cuts retains rigidity, they are dry and do not absorb the sauce well. When you buy the market “freshest” meat, it is usually at this stage, so the dishes from it do not meet the expectations of inexperienced cooks. With rigor mortis, the muscle fibers are shortened, so such meat is difficult to chop and even more difficult to cut with a knife.
The ripening rate of meat depends on the type and health of the animal, its fatness and age, but on average, 1-3 days of storing the carcass at a temperature of +4 to + 12 degrees is sufficient. 24-72 hours after slaughter (the exact time for each carcass is individual, as it depends on the ambient temperature, air access - aeration - and other factors), the meat acquires new qualities: its hardness disappears, it becomes juicy, elastic and aromatic. You can identify a ripe cut by simply pressing your finger on it - a hole forms in the meat, and it is also perfectly cut with a knife. A "crust" forms on the surface of the ripened meat, it does not shine, the color is darker intense than that of a steamed product.
But long-term aging of meat at positive temperatures after a while ceases to be of benefit to it, the process of autolysis begins, in common parlance, rotting. It becomes covered with mucus, at first it loses its aroma, and then acquires a specific smell, darkens noticeably, and then turns green. Homemade meat aging is a complex process, and people with certain knowledge and experience should be involved in it, therefore, if you are not going to cook the product immediately, it is better to refuse to buy fresh meat.
