Good question lingr ..... Different people have different opinions on the subject. I probably could not explain it correctly so I looked up numerous articles and I think this one explains it most completely and shortest. It came out of Field and Stream.
There are some persistent myths about aging venison that may cause you to stock your freezer with inferior meat this season. I'm sure you've heard them: Deer meat can't be aged like beef, because it dries out if left hanging. Or: Aging is simply "controlled rot," and why let good venison rot? And: You only need to hang deer a day or two for tender meat, so any longer is a waste of time.
None of this is true. To understand why, and to find out the best methods to age venison, we have to turn to science.
A Chemistry Lesson
Despite its different taste and lower levels of fat, venison is very similar to beef. It contains the same basic enzymes, particularly lactic acid, and goes through similar changes after the animal dies.
First, the muscles go into rigor mortis, a stiffening lasting at most 24 hours. Butchering a deer during rigor mortis is one of the worst things you can do. It can cause a phenomenon called shortening, where the muscles contract and remain tougher than if butchering took place a day later.
Proper aging begins as soon as rigor mortis ends-and this process is definitely not controlled rot. Rot is zillions of bacteria eating the muscle cells, their waste products creating the familiar stench of decaying flesh. Bacteria attack only after meat is exposed to the air, and bacterial rot is accelerated by higher temperatures. It doesn't happen at all if the meat is frozen. To properly age your deer, you must keep it at temperatures above freezing and below about 40 degrees. This holds bacteria (and rot) at bay, allowing natural enzymes to do their work.
Venison, Restaurants, and Supermodels
Meat is made up of long muscle cells connected by a fairly tough substance called collagen (the same stuff plastic surgeons inject into the lips of supermodels to make those lips full and "pouty"). Collagen causes most meat toughness. Young animals have little of it between their muscle cells, but as an animal gets older, more develops. Natural enzymes break down this intercellular collagen as meat is aged, so the longer it hangs, the more tender it becomes. (Commercial meat tenderizers, such as papaya juice, do the same job-but natural aging is more flavorful.) This is why beef served in fine restaurants is aged a couple of weeks or more. It's also the reason a prime restaurant T-bone costs so much; it takes money to cool a large aging room.
Supermarket beef is aged perhaps two to three days. This isn't bad, since beef-or a deer-hung that long does age slightly. But neither becomes as tender or flavorful as after a week or more.
Aging at Home
Maintaining a consistent temperature is the main problem with home-aging venison. I live in Montana, where outside temperatures during the firearms season normally range from around 20 at night to 40 during the day. My garage provides some protection against cold and sunlight, so deer that I hang there won't usually warm to more than 40 degrees and won't freeze at night. If your weather isn't ideal, you can home-age venison in a spare refrigerator. Skin the quarters and bone-out other large sections of meat. The quarters from a typical deer (or even two) will fit in an average-size refrigerator.
Young deer don't have much collagen, so aging for a couple of days is plenty. Older bucks benefit most from the extended period, and many hunters who do it properly actually prefer the taste of mature bucks. After aging, the steaks are as tender as a young doe's-but with a rich flavor reminiscent of the best restaurant beef.
**** Hope that explains my, and others reasoning. Since Sunday when I shot it highs have been around 42 with lows in mid 30s. It was a young deer so 2-3 days hanging was good. Mine hang in the barn out of the sun and even if it gets down to about 25 don't freeze. I use a body sock to keep off bugs/dust/ect. Today was going to get above 45 so I worked it up this morning. The Grandsons two were year old deer so they hung in same temp for 3 days also. If its hot when I shoot them I qurarter them and put in the fridge for X number of days (depending on age) before working them up. Some of the processing plants around here charge you to let your deer hang in their coolers also before processing them.