NOT MINE, from a processor, and basically what I follow (except we have a walk in cooler and I let it hang for 1-2 weeks):
For years we have all been taught by our hunting mentors to soak deer and hog meat in ice water. I’ve heard some hunters say soaking the meat overnight is enough and others who prefer a week or more. This is one of the worst things to do to any animal carcass after its slaughter. Putting the meat in water allows bacteria (primarily E. coli) to grow and spread over the entire carcass. It also removes all of the flavor from the meat. Imagine eating a good ribeye after soaking it in water for a week.
Years ago, before hunters started feeding deer like they do today, deer meat had a strong gamey taste. This led to the practice of soaking the meat to remove the gaminess. Actually most of the deer we harvest today have access to more and higher quality feed than what we feed the vast majority of our cattle and domestic pigs in this country. This leads to a higher grade of meat which lacks much of the typical gamey taste.
I put together the following guide to educate hunters how to properly care for their kill in order to give them the best tasting meat possible (and also the longest shelf life). I have slaughtered cattle, pigs, goats, and sheep for a living for over 30 years. I am also an avid hunter and the method outlined here is how I personally clean and prepare my kill EVERY time. Good luck hunting!
After the Shot. The first thing to do is properly bleed the animal. Cut the jugular vein as soon as possible. It minimizes blood clots and bruising that occur around the shot area (especially with a shoulder shot). It also cleanses the meat of lactic acid buildup that occurs when a deer runs off after getting hit (this is even more important when a deer is running from dogs). Lactic acid adds to the gaminess of the meat.
After Skinning and Gutting. Leave the carcass hanging and do your best to remove any feces and hair. Use a sharp, smooth knife to trim any areas with visible signs of feces and discard them. Remove as much hair with your fingertips as possible. If the shot was in the shoulder, use your knife to open up and lift both shoulders to trim away any bruised or bloody meat.
Washing. At this stage use your hose to clean the carcass as best you can. Use a heavy stream and be sure to get the inside of the stomach cavity and any other bloody or messy areas such as the neck, pelvic area, and under the shoulders if you opened them up after a shoulder shot. At this stage, water is your friend.
Dry, firm, cool carcass ready for processing.
Hanging. After washing the carcass, leave it hanging to let it dry. If the temperature is below 48 degrees, the carcass can easily be left out overnight. The longer you can hang it, the better. Hanging the carcass lets excess blood drip out of the meat, allows the surface of the meat to dry up, and causes the meat to firm up so it is easier to debone. After the surface is good and dry, it will be easy to pick off any hair or trim any blood or feces that was missed earlier. Even if it is fairly warm, you can hang the carcass as long as 2-4 hours.
Packaging. When you are ready to ice down the carcass, break it into quarters or halves. At this stage, use care not to allow the meat to get wet again. Put each piece separately into plastic bags (garbage bags, ice bags, etc. the thicker the better to prevent bones from puncturing the bag) and tie or seal the bags tight. Put the carcass into ice chests in layers. First put a layer of ice on the bottom, then put one or two pieces of the carcass, add ice and repeat. Always cover the top of the meat with ice (cold air sinks). Pull the plug on the cooler so water does not build up in the cooler. Check the cooler regularly and add ice as needed. You should get the meat to a processor as soon as possible; preferably within 3-4 days.
Final Word. The process described above will minimize the spread of bacteria, make the job of cutting up or deboning the meat much easier and cleaner, and also maximize your yield of meat. The end result will be a much better tasting final product.