Beef Aging - Dry-aged Beef

Dry-aged beef is beef that has been hung or placed on a rack to dry for several weeks. After the animal is slaughtered and cleaned, either an entire half will be hung, primal (large distinct sections) or sub primal cuts strip loins, rib eyes and sirloin will be placed in a refrigerator unit, also known as a "hot box". This process involves considerable expense, as the beef must be stored near freezing temperatures. Subprimal cuts can be dry aged on racks either in specially climate-controlled coolers or within a moisture-permeable drybag . Also, only the higher grades of meat can be dry aged, as the process requires meat with a large, evenly distributed fat content. For these reasons one seldom sees dry-aged beef outside of steak restaurants and upscale butcher shops or groceries. The key effect of dry aging is the concentration and saturation of the natural flavor, as well as the tenderization of the meat texture.

The process changes beef by two means. Firstly, moisture is evaporated from the muscle. This creates a greater concentration of beef flavour and taste. Secondly, the beef’s natural enzymes break down the connective tissue in the muscle, which leads to more tender beef.

Dry aging of beef is rare in super-markets in the United States today, due to the significant loss of weight in the aging process. It is found in steakhouses and certain restaurants. It can also be done at home under refrigeration by various means--open air, with the presence of salt blocks and with the use of a moisture permeable drybag to protect the meat while aging.

The process of dry-aging usually also promotes growth of certain fungal (mold) species on the external surface of the meat. This doesn't cause spoilage, but actually forms an external "crust" on the meat's surface, which is trimmed off when the meat is prepared for cooking. These fungal species complement the natural enzymes in the beef by helping to tenderize and increase the flavor of the meat. The genus Thamnidia, in particular, is known to produce collagenolytic enzymes which greatly contribute to the tenderness and flavor of dry-aged meat.

When dry aging using a moisture permeable material, surface mold growth is not present, flavor and scent exchange within the refrigerated environment is not a concern and trim loss of the outer hardened surface is measurably reduced (see Kansas State University study in references). Flavor and texture profile is similar on all dimensions to traditionally open air dry aged results.