Boiling your deer skull is only one of the methods to prepare it for a European mount, and it requires a little work and help from some chemicals to speed up the process and make the skull look its best when mounted.
5 Things to Put in Water When Boiling Deer Skull
Technically, you don’t boil the skull in the water – you simmer it. The water needs to be boiling hot to make an impact, but if you leave your skull in too much heat for too long, the bone becomes brittle and shrinks.
To aid your simmering water with cleaning the skull from meat, grease, and brain tissue, you have a choice of chemicals, depending on the desired outcome, depth of your pocket, time allotted for the task, or simple preference.
The most common ingredient for skull boiling is your standard dishwashing detergent.
While the heat usually does most of the job of softening the meat on the skull, there is still plenty of grease that can stain your skull.
The dishwashing soap is designed to wash off grease from your dishes and can easily wash it off the skull as well.
Some people prefer to use other chemicals first to get rid of most of the pesky meat, cartilage, and fat tissues, and then on the second or third change of water, put some dishwashing soap.
Using a dish soap is a very popular method to wash the grease off and one of the easiest. The dish soap is readily available in any convenience or grocery.
The amount of soap needed to degrease the skull may vary depending on how big it is and how concentrated it is. Most dish soaps are similar, but Dawn is meant to be a little bit more concentrated than other soaps, dealing better with “tough” grease.
There is, however, a little snag with using the dishwashing soap for degreasing. Depending on the color of your soap, it may slightly stain the skull after a while. It is best to use a clear dishwashing soap for your deer skull to avoid discoloration.
Some people even try dishwashing tablets instead of soap with equal results.
Borax is one of those chemicals that have a lot of use in many instances, like tanning your hide, and it also helps dissolve the soft tissue from the skull.
Borax is a hydrated borate of sodium, which means it’s a type of salt. It is mainly used as a household cleaner and laundry soap booster.
There is no set recipe for how much borax one should use when boiling deer skull, but the most common is about 1/2 cup per one gallon of clean water.
The borax solution deals really well with any stubborn tissues, like cartilage, brain, or blood that don’t want to come off the skull.
While simmering the skull in borax solution, you should proceed cautiously, as breathing in a lot of fumes can cause nose and lung irritation. You should also wear gloves when dealing with borax. The skull needs to be properly rinsed after using borax.
You can get borax in a concentrated powder or powdered detergent, like 20 Mule Team, that contains boric acid. Borax is available in Walmart, farm supplies, or health food stores.
Another chemical that helps soften the tissue is baking soda. It is also considered a safer substitute for borax.
It works wonders on burned pots, pans, and carpet stains and will be perfect for aiding your skull-boiling task.
It also helps with finalizing the skull as a whitening agent, and it’s available in every Walmart.
Baking soda or sodium bicarbonate is often used for baking and cooking, and mixed with acid, like vinegar or lemon juice, produces carbon dioxide. 
What is also interesting is that baking soda used with toothpaste helps whiten your teeth and remove plaque. The same effect it will have when added to water while simmering your deer skull.
While there is no plaque on the skull, there is fatty residue and soft tissue, which baking soda helps remove. It usually jellies the soft tissue making it easier to pull or scrape off.
There are a lot of recipes for baking soda simmering solution, but the best so far seems to be a half cup of baking soda per one gallon of water.
Soda ash (sodium carbonate) can significantly reduce the boiling time, and it’s easy to get from a taxidermy shop.
Soda ash in cleaning products and toothpaste acts as a bubbling agent, helping the cleaning product get into tight spaces. It is also used in hair dyes to break down hair oils.
It has the same properties when used in a simmering solution for your deer skull, getting into all the tight spots on the skull and breaking down soft tissue.
Soda ash is also good for removing stubborn stains from the skull by lowering the surface tension of water. It makes it easier for water particles to mix with detergent.
It doesn’t take a lot of soda ash to do the job – usually, a tablespoon per gallon of water, and apart from taxidermy shops, you can buy it in the pool care section in Walmart.
Hydrogen peroxide won’t help you break down the soft tissue on your deer skull, but you can consider it a part of the process of making a European mount.
Although one should never heat a high percentage hydrogen peroxide, some people add a small amount of 3% to the simmering water. It is not advisable to do it indoors just in case it gets unstable.
Heated hydrogen peroxide produces enough oxygen that, when mixed with fire, can cause a big enough explosion to destroy the pot, whatever is in it, and the closest vicinity.
The best and safest way to bleach the skull with hydrogen peroxide is after simmering.
Hydrogen peroxide is usually used as an oxidizer, bleach, and antiseptic. One can find it in Lysol cleaner or hair developer.
The best solution would be 12% H2O2 mixed with cold water in a ratio of 1:3 H2O2 to water. 
The skull should be soaked for about 24 hours in the solution. Remember to avoid soaking the antlers, as they can also get bleached, requiring you to use some magic to bring the color back.
It can also be used with baking soda to make a paste. The paste can be applied to the skull, wrapped in plastic, and left for 24 hours in a warm place.
Hydrogen peroxide is a safer way to whiten your skull than your traditional bleach because, as opposed to bleach, it doesn’t make the bones brittle.
There are many ways to boil the meat of the skull, and most of them would successfully yield a fantastic, snow-white skull that makes an impression on the wall.
Some chemicals can be used together, like dish soap and baking soda, or used interchangeably with every batch of fresh water.
Those chemicals can also work on other skulls, like elk, moose, or bear.
- E.B. Bennion, G.S.T. Bamford, The Technology of Cake Making, p. 102