here's an article I came across for rabbit pelts. I would assume the same process could be used for deer hides. I have yet to try this process myself.

WASHING AND COOLING THE SKIN
Once the butchering duties are finished, thoroughly rinse the hide in more cold water to finish cooling it as quickly as possible. Don't worry about any remaining fat and tissue at this point . . . rather, apply your effort to washing away all the blood left in the skin, since any that's not removed will leave permanent brown stains in the leather after tanning. (Soap or detergent is really unnecessary, but if you do use such a cleanser, be sure that all traces of that are rinsed out before you proceed, too.) With the rinsing done, carefully squeeze (never wring!) the excess water from the pelt.
As an alternative, you can clean skins in your washer (use the delicate cycle, if your machine has one), but there is a possibility that bits of fat and hair will plug up the drain hose. To avoid this problem, I prefer to handwash the pelts (which also gives me a chance to examine the furs closely).
Thoroughly cleaned hides can be preserved for later processing by freezing; drying on a stretcher, or salting and drying. I store my pelts in the freezer if I have more than I can comfortably work on at one time. Before freezing them, though, I make sure that all the body heat is cooled from the skins, and that the excess water has been pressed out . . . then I wrap the hides in freezer paper — or store them in airtight containers — to prevent dehydration and freezer burn.
(A hide can be opened up — that is, split from head to tail along the belly's midline — at any time during the tanning operation, but I prefer to wait until the process is complete to do this.)
THE FIRST TANNING SOLUTION
When the pelts are clean and cooled (or have been defrosted, if you've been sidetracked for a while), you're ready to begin tanning. You'll first need to round up a four- to six-gallon plastic container (a wastebasket or bucket will work fine). Then pour two gallons of room-temperature (about 70°F) water into the pail, and add either — but not both — of the following recipes. (Each formula will be adequate to tan six to nine medium-sized pelts.)
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TANNING RECIPE NO. 1:
SALT/ALUM
1 cup of coarse or granulated salt (not iodized) 1 cup of common alum (aluminum sulfate or any of several similar double sulfates), powdered or granulated


TANNING RECIPE NO. 2:
SALT/ACID
1 pound of coarse or granulated salt (about 1-3/4 cups) 1 ounce of full-strength sulfuric acid, or 4 ounces (1/2 cup) of battery acid (dilute sulfuric acid)
[/align]You can buy a five-pound sack of the necessary salt at almost any grocery store (look for noniodized pickling salt) for about $1.00. And larger quantities (usually 100-pound sacks) are available from chemical companies and other sources at "bargain" bulk prices.
Alum is stocked by biological supply companies, handicraft and leather shops, chemical suppliers, pharmacies, and feed stores. It comes in both a commercial and a medicinal grade (for tanning purposes it makes no difference which you use) and generally costs between $1.00 and $3.00 per pound.
Battery acid (electrolyte) is available from auto supply houses for about $1.00 per gallon (128 ounces) and is usually sold in five-gallon containers. (I've never worked with full-strength sulfuric acid, because I feel it's too dangerous.)
Both recipes work well and take approximately the same amount of time. I prefer the somewhat more expensive alum mixture because it produces a whiter, softer leather with the feel of fine suede.
Once you've determined which method you're going to use, add the chemicals to the water (don't let them splash) . . . and make sure the powders are completely dissolved before you add the pelts. Be certain to show respect for your chemicals and to handle them properly. (Wear rubber gloves if you're working with sulfuric acid.)
Now, drop each skin into the pickle (as the tanning mix is called) and swish it around with a wooden stick or spoon (or use your glove-sheathed hands) to work the solution into the fur and skin. Allow the pelts to remain in the brine — at room temperature (65-70°F) — for 48 hours, stirring them at least twice a day. If the pelts tend to float to the top of the solution, weigh them down . . . using a glass jug filled with water or a clean rock.
After the two full days have passed, squeeze the excess brine from the skins (save the solution . . . you'll reuse it later) and rinse them in cold water.
FLESHING
Fleshing is the process of removing the fatty tissue and flesh to expose the actual leather (or derma) to chemical action. Rabbits have a clearly defined undertissue which, after the first chemical soaking, can be peeled off in one piece (if you're careful). Since the flesh separates most readily at the rump section, I usually start there and peel toward the neck. A steak knife can be used to scrape and loosen the difficult areas you'll likely encounter on the belly and around the legs. Be careful not to peel too deep and expose the root hairs, but do try to get off as much fatty tissue as possible.
When you're finished, rinse the fleshed hides in cool water and then squeeze out the excess liquid.
THE SECOND TANNING SOLUTION
Now, go back to the recipe you chose before, add the same amount of salt/alum or salt/acid as you used in the first soaking solution to the reserved brine . . . and follow the same mixing procedure. Put the pelts in the liquid, one at a time, working each hide thoroughly to coat it with the pickle. Keep the skins soaking at room temperature for seven days, stirring them at least twice a day.
You can test for tanning "doneness" after the week's up by simply boiling a small piece of hide for a few minutes in water. If the leather curls up and becomes hard and rubbery, return the pelt to the solution . . . because a well-tanned skin will show little or no change in boiling water.
DRYING AND FLUFFING
After one pelt has tested "done", remove all of them from the solution and squeeze out the excess pickle. The tanning brine will likely be pretty much used up if you've soaked the recommended number of skins, but any liquid that does remain should be dumped out. Take care to discard the mixture where farm animals can't drink it and the chemicals won't contaminate drinking water. (Although it's not poisonous to handle, the brew might be fatal if taken internally.) I generally pour any leftover solution along pathways to keep them free of weeds.
Next, wash each pelt thoroughly with a mild detergent. I use an inexpensive cologne-scented shampoo that leaves the fur soft, fluffy, clean, and sweet smelling. Then rinse the hide several times in lukewarm water and squeeze out the excess liquid. Hang the pelts in the shade to dry (I usually put them on a temporary clothesline suspended over the bathtub). It'll take from six hours to two days for the skins to become fully dried, depending on the temperature, the humidity, and the thickness of the leather. (Don't ever put wet hides in direct sun or near a heat source, as they'll quickly shrink and become brittle as they dry.)
When the pelts are just barely damp, toss them in an electric dryer, with no heat, for 15 to 45 minutes. This step can be omitted . . . but the machine fluffing does make the fur easier to work with and the next procedure less difficult.
WORKING THE LEATHER
Ever since animal hides were first turned into leather, they've been pounded, rubbed, chewed, and beaten — and often annointed with grease or oils — to make (and keep) them flexible and soft. I stretch partially dried hides to soften the leather, using a process known as breaking the skin.
Pull the skin of your damp pelt in all directions, working only a small area at a time. The leather will begin to turn soft and white. The trick is to catch the hide while it's still slightly wet and limp. If it becomes too dry and turns hard, resoak it with a wet sponge (this is called damping back) until it's pliable enough to stretch again. Be firm as you pull the leather, but don't use too much force, or you might tear it. Keep up the skin-breaking procedure as long as necessary . . , until the pelt remains soft as it dries. ("Broken" hides may be tacked to a board or frame to encourage them to dry flat.)
FINISHING AND STORAGE
After the hide has dried and is sufficiently soft, give the fur a good brushing with a small hairbrush. Then massage mink oil (I buy it at shoe stores . . . where an eight-ounce container, which is enough for several dozen pelts, costs about $2.00) into the skin side of the hide with your fingers. (You'll be glad to know that mink oil is a wonderful hand conditioner.) As a final — optional — step, try buffing the leather with pumice or fine sandpaper to give it a soft, velvety feel.
Rabbit fur, like all leathers, breathes . . . that is, it contains microscopic spaces for air circulation. Therefore, it's best not to store rabbit pelts (or any other fur or leather) in airtight containers (except, of course, when you're freezing them before tanning). I keep my finished hides in a cardboard box with a bar of sweet-smelling soap, which repels insects and helps to scent the furs.