Dry-aging beef means that once the animal is slaughtered and butchered, portions of the carcass are allowed to rest in very carefully controlled conditions (cool temperatures, with relatively high humidity) for a period of time—often several weeks, and sometimes months.
When we create such conditions, we allow enzymes to do their work. And we end up with a complexity of flavor that just wasn’t there before. There’s no cooking method that can generate the depth of flavor of a dry-aged piece of meat.
What happens is that enzymes in the meat’s muscle cells begin to break down proteins, fats, and glycogen into amino acids, fatty acids, and sugars.
Dry-aging beef also causes it to lose some of its moisture. Meat begins at about 75 percent water; after dry-aging, it may go down to somewhere around 70 percent. It doesn’t sound like much of a change, but what it means is that the flavors and tissues become more concentrated. Dry-aged meat is still juicy when you cook it, but the juices are even more delicious than usual.
In short, it’s wonderful, delicious stuff.