“Wet aging” of primals and large muscle roasts is a process used by many custom meat producers, restaurants, BBQ competitors, and home meat processors. Examples of a primal is a beef loin (the roast that strip steaks are cut from) or a beef tenderloin (the roast that fillet mignon is cut from). The best example of a roast that can be wet aged is a brisket. When wet aging the meat is packaged in it's own juices and there is an abundance of natural enzymes present. During the aging process, these enzymes tenderize the meat. Wet aging begins the day the primal or roast is packaged. Since meat is shipped cold, and stored in special coolers it's technically wet aging this entire time.
There are three key factors critical for wet aging: 1. The primal must remain sealed in the original Cryovac bag in which they were sealed by the packer. 2. You must know the pack date / kill date of the animal. This information can be found on the end of the boxes that the meat is shipped in. 3. You need a controlled temperature that is around 30° – 34° F. A second refrigerator (aka beer fridge) is perfect. Beyond that, all that is required to wet age successfully is time.
Wet Age Time - I like to wet age beef for 28 to 35 days. I have heard of some restaurants and home processors that prefer 45 to 60 days for their wet aging. If you are not ready to eat your wet aged beef at the end of aging time it's okay to freeze it in the same packaging. I generally try to eat it within 2 months.
Notes on Pack Date - When wet aging, it is not recommended to buy beef from the meat case because you don't know the actual kill date, and you have no idea how the packages of beef have been handled once they moved from the walk-in cooler to the meat case. You need to ask the butcher if you can select meat which is still in the cases. Just tell them you are wet aging and they should understand the procedure, and the time requirements you are using. I like to wet age all of my briskets about 30 days, and sometimes the kill date will be as close as 6 or 8 days prior to my purchase. Now I know I can wet age the brisket for about 20 days at home before cooking. Sometimes I get lucky. One year for Thanksgiving I wanted to serve a beef tenderloin roast, and my Sam's Club had some USDA Prime beef tenderloins still in the boxes with a kill date about 25 days prior. Perfect! Sam's did most of the wet aging for me in their walk-in cooler and I can age for a week at home and still meet my preferred wet aging time.
What to look for when wet aging - Obviously you want a cold refrigerator. And you don't want a punctured or leaky Cryovac bag because this can let bacteria in. Because I routinely rotate my home cured products like bacon and ham, I do the same for wet aged meats. If you notice areas of your meat is freezing, move to a different spot in the refrigerator. If the meat freezes, it slows the aging process. You may see some air bubbles in the Cryovac bag, this is from the proteins breaking down and is normal.
Opening the Cryovac - It's common to notice a distinct odor when opening a Cyovac bag that contains wet aged beef, this is due to the lack of oxygen in the bag. It's not a bad odor, and the odor dissipates quickly within about 10 minutes with the help of fresh air. And if the meat is rinsed (or the purge liquid) is blotted off, the odor will go away a little quicker. If the meat has a strong pungent 'off ' odor.... this indicates the meat has 'turned' (bad), the smell will be almost over powering when you open the package. Discard it where no pets or wildlife could access it. For what it's worth, I have never had a package of wet aged beef turn. There is some controversy about rinsing large cuts of beef. Some cooks recommend blotting with paper towels only. Others prefer to rinse. If you do either of these in a sink, be sure to limit splashing and always disinfect all surfaces with a Clorox type of spray. I prefer to rinse and blot my wet aged beef in a plastic bus tub. This is easier for me to control and sanitize. When I discard the liquids in the bus tub, I sanitize the sink.
Seasoning and Cooking - Once the meat has been rinsed (or blotted) and dried, perform your normal trimming and seasoning. Then cook using your favorite method.