Dry aging is a process where steaks are hung on a racks in a temperature and humidity controlled room for 21 to 120 days in order to tenderize the meat and make it taste umami style and flavorful. During the aging process, the moisture is drawn out of the meat, to make it more flavor and concentrated. In addition, during the process, the steak natural enzymes work to break down collagen in the meat and essentially decomposing it. Collagen is what makes muscle tough, and when aging it starts to break down and meat becomes tender.
7-Days Aging : The collagen has starts to break down but the steak won't have the flavor or texture of a dry-aged steak yet. The meat is still fairly bright but it will darken as it ages and become drier.
21-Days Aging : The steak has lost 10% from its original weight, through evaporation process. The water has been seeps out on the surface and back of the meat but the fat and bone at the sides of the steak makes it waterproof. As the meat shrinks, the steak will become more concave as it ages. Even though the fat doesn't shrink, it does darken during aging process.
30-Days Aging : At this stage, the steak has lost 15% of its total weight and this is the most requested and preferable in dry aged steaks. As the steak has developed the flavor and texture qualities associated with dry-aged meat. It is very tender, with a flavor I can best describe as a mix of buttered popcorn and unique roast beef.
45-Days Aging : The steak has lost only a fraction more weight and the flavor of the fat changes before the meat does, so it's important not to trim off all the fat before you cook it. The steak has a little bit more flavor than one aged to 30 days.
90-Days Aging : The white striations on the surface of the meat are good mold and has salty taste. The crust that develops around the meat protects it in the same way a rind does with cheese. The exterior crust is shaved off before the meat is sold. What you’re left with is a steak that is slightly darker and drier in appearance than fresh steak, but to the untrained eye the two might be indistinguishable.
120-Days Aging : This is the longest time taking to dry-aged a steak. The steak has lost 35% of its original weight. A steak aged this long has a very funky flavor and it’s also very expensive, so it is suitable for someone who really appreciates an intense beef flavor and meat lover.