What is aged beef?
No doubt you've heard of aged beef. Usually fancier restaurants will tout their beef as 'aged for X days' or 'dry aged' or 'wet aged'. But, what exactly are they telling you?
Aging meats is not a new concept. Our ancient ancestors would hang their kill until it was considered 'high' or 'gamey'. Some of this was out of necessity, since refrigeration was still hundreds of years away. Even so, they recognized that the meat that they left hanging longer was more tender and better tasting than it had been fresh.
What actually happens when you age beef?
On a scientific level, the muscle fibers are being broken down. This does not mean that the meat is rotting. There has been some misconception here, and it's most definitely an important distinction.
When aged at 33-37 degrees, the muscles continue to use hemoglobin and produce lactic acid. In turn, that lactic acid breaks down muscle fibers and connective tissue. Again, this is a natural process utilizing compounds already present in the muscle cells. The 'fork tender' beef we all seek is nearly impossible without aging.
Another aspect of the aging process is evaporation. Just like simmering a pot on the stove to remove water and concentrate flavors, the aging process makes the meat more flavorful by removing flavorless water and intensifying the beef flavor. The carcass can lose up to 15% of its weight if aged 21 days. This is the primary reason that mainstream beef is generally not aged after slaughter. It's too good a deal for the meat packers to sell you water by the pound at the meat case! There is also the added cost of cooler space and refrigeration during the aging process to consider.
What is the difference between dry aged and wet aged?
Dry aged beef is aged in a refrigerated space in open air. It can be done as a whole carcass in a large locker or in special refrigerator units designed to hold only a few pieces.
Aging the whole beef is less common because it takes up a lot of space and the carcasses must be inspected regularly. As we pointed out earlier, we are not interested in outside bacterial activity, and eventually that will happen so diligence is required! More marbled beef can tolerate longer aging times and leaner beef will require shorter aging periods. It is an equal blend of art and science and it takes some practice to learn what optimum aging looks like.
Small aging refrigerators (which you can buy for home use too) generally age only a few cuts of meat at a time. A whole rib or other section that will be cut into steaks are good candidates for these machines. They can handle long aging times by precisely controlling humidity and temperature. However, extremely long duration aging will require some trimming of external bacterial growth. As long as the finish product is properly seared at cooking and the trimmer knows what to look for, this poses no danger.
Wet aged beef is aged in pieces in vacuum sealed bags. The sealing out of oxygen virtually eliminates the risk of rot during a normal aging duration. Furthermore, the sealed bags also eliminates evaporation of water. This is desirable to the beef industry because it means there is no weight loss during this process. You, as the consumer, are buying the water too. However, it also means that the flavors are not able to be concentrated in the same way as dry aged beef. It is generally accepted that wet aged beef is milder in flavor. However, the same muscle breakdown does occur and wet aged beef will be more tender than unaged beef.
So how long should beef age?
While restaurants like to get competitive about their aging duration, the truth is that most of the work is done in the first 14-21 days. There are some processes that continue to occur for much longer and you could go down a rabbit hole of research on enzymes and certain fungi that are considered beneficial to long term aging, but the end result is often not readily distinguishable to most consumers.
We attempt to age our beef for 21 days. At 14 days the carcasses are inspected daily and are taken down for processing whenever it is decided they shouldn't go any longer. This provides our customers with all the benefits of aging, without any of the risks associated with longer aging periods. Since we age the entire carcass, we often get compliments from customers about the unexpected tenderness and flavor of certain cuts of meat like roasts! Aging is one of the primary reasons why farm to table beef often tastes different than mainstream store beef.
While aging always improves tenderness and flavor, there is still no substitute for good genetics and a properly finished beef. No matter how long you age an older cull cow, you will not create a great steak. But, it is possible to miss out on a great steak by not aging an otherwise great looking side of beef.