Bad Words: BOIL & BLEACH

'I continually hear the words 'bleach" and 'boil' come up in topics involving bone processing. Which is exactly where they should never be.

Keep in mind first of all, there is no one way to process animal remains to get the bones. My blog posts here are just my opinion from my own personal experience. I've been collecting bones for 33 years now and I still learn new things all the time. Best way for you to learn is from your own experience.



There are two standard rules of what NOT to do:

1) NEVER BOIL BONES

I think the word 'boil' pops up a lot because of one bone defleshing process called the European skull boil method. Which is very poorly named. You want your water to simmer, not boil. Although I never use this method myself and avoid any kind of heated method.

Boiling causes fat to soak into the bone. Leaving you with a greasy, smelly and yellowish bone. Which can go rancid if left as-is as many do that use this particular process. Yes, grease can be removed with ammonia or dish soap soaks and patience. This is a slow process which can take weeks or even months. But when you actually use a heated defleshing process you're making a lot more work for yourself driving the grease deeper into the bone, not to mention degrading the bone quality.

Boiling can also weaken and break bone that has already started to decay from being highly weathered or buried. Turning smaller bones to mush, causing fragile bones like those in the nasal cavity to fall out and often cracking enamel off of teeth. So instead, slow simmer if you absolutely must. If you see bubbles, your water is too hot! Though, I personally no longer use any kind of heated processing method ever. I opt for maceration and patience leaving me with a higher quality bone.

In my experience the more unnatural processes you put the bones through the greater the chances you are lowering the quality of them.

2) NEVER USE CHLORINE BLEACH ON BONES

Chlorine based bleach permanently damages the bone itself. It will start to break down the structure of the bone and will continue to even after it is rinsed and dried. Resulting in chalky, fragile and extremely porous bone that will turn to bone meal with age. Not to mention it turns the bone yellow. Which pretty much defeats the purpose if you are trying to whiten the bone. Once it yellows from bleach there is nothing you can do about it. Believe me, I've tried to salvage yellow bleached skulls before with hydrogen peroxide to no avail.

Instead, to whiten bone use regular 3% household hydrogen peroxide (H2O2) that you can easily and inexpensively get ahold of at the grocery store, dollar store or drugstore. Pure is fine but if you are really concerned about something small/fragile you can do a 50/50 bath with water. Pour your H2O2 just above the bones in a loose lidded plastic container to reduce evaporation. For H2O2 use it is best to stick to plastic containers as it can have a negative chemical reaction to some metals! You want to avoid using glass jars with lids for any bone processing step as pressure will build up inside (maceration or H2O2). Oxygen activates the peroxide so you want to let air get to it. But it will evaporate so keep an eye on it and top it off as needed. Also, if you have a tight lid on it pressure may build up and the top literally blows off and you'll hear a "pop", ha!

How long? Be patient. Just keep the bones in this bath until they are a shade darker than you want them. They will dry lighter. This process can take days or weeks. This is a very safe process for most bones if you properly follow my steps. When done whitening lay the bones out to dry where pets, wildlife or children can't get to them. I have a ceiling fan on my front porch and that's my drying station as the sun gets to them as well. IMPORTANT: Be sure the bones are completely dry before you put them in a sealed container for storage or they may mold on the outside or even turn black inside. If you see mold immediately put them in H2O2.

Important factors: If your H2O2 bath gets really cloudy you likely need to dump it out and start a new bath. Otherwise it will start to macerate instead. Please DO NOT ever pour H2O2 out outside on the ground as it horribly will kill the creatures living in your soil! Do not use metal containers or tools with H2O2. Store in a cool dark place. Direct sunlight will eventually deactivate H2O2 that's why it comes in dark containers. Do not do this step outside with no lid. You will just end up with deactivated H2O2, algae and insect larvae all over you bones and you'll have to start over... or the bones may be ruined. Plus you'd be killing animals that may get into it and it is not safe for pets or wildlife to drink!

DO NOT use hair developer type peroxide on bones, ever. There are additional ingredients in it besides H2O2 and it is MUCH stronger than regular H2O2. Which is only 3%. I have experimented with this myself and the developer turned huge deer vertebrae to literally mush in my hands. Likewise, do not use the powdered hair bleach packets. The same results will happen. So you've been warned! I see a lot of people using/suggesting hair products like this. If your argument is that you're saving money, you can just get pure food grade 12% hydrogen peroxide and water it down like this here. I have used this one myself.

Degrease or Whiten? You can alternate back an forth between degreasing and whitening with H202 as much as needed. But you want to be sure the bones have already been defleshed and cleaned of all dirt/fur/etc before putting into the peroxide. With larger skulls, after maceration I often followup with whitening instead of degreasing. This way I can see the exact state of the grease better than if I had not to know how to more forward with degreasing. You often can't tell if you're seeing soil or maceration staining vs grease after maceration.

Additional notes: Some soil staining will not come out especially if bones were decaying on the forest floor for some time or buried. But you can keep trying, letting dry then repeating. Highly nature weathered bones found out in a field will likely stay a grey color. But trying to degrease/whiten them you could end up degrading or destroying them. So use caution doing so.


Too late to clean and whiten these bones. After bones have been left in the elements for some time they begin to break down. These bones are now "living" again covered with algae/fungi that is eating it and will be part of the soil soon. This is one reason I choose not to do the bury method. If you wait too long bones have already begun to decay. I like processing methods where I can see what is happening to the remains at all times.

To deflesh bones you have a number of options but I use two processes the most:

A) Nature Cleaning (some call it Range Cleaning like as in cows dying out in the pasture and left there to decay) - Put the animal remains in a cage and leave outside so that the insects, rain and sun can do their job.


One of many carrion insects - the American Carrion Beetle, Necrophila americana.

You want it in a cage so that scavengers won't run off with limbs. You want to be sure to do this. Believe me, even insects have taken off with my bones in the past. Sometimes I also add a thin screen under the bottom of the bone cage to catch any really small bones that fall off. (Note that since I originally made this blog post I now have rows of much better bone cages that I will make a full post about at another time and link here but for now here's a shorter version. The one below has many flaws and in the end did not work well).


Wild boar head, jaw and tail in cage mounted to tree.


Nature cleaned deer remains, ready to macerate.

B) Maceration - Try to remove as much loose fur/flesh as you can by hand. Don't yank it it, that can break the bones! If it is mummified you may be able to cut off dried flesh parts with scissors. Then put the animal remains in plastic lidded container fully immersing it in water. This can be an inexpensive process reusing old containers - 5-gallon buckets, old cat litter plastic tubs, old plastic coffee contain are all great for this purpose. This is rotting process. Involving the living bacteria that break down the flesh on the bones. I try to put as minimal flesh in for this step as possible. When doing so I never even have to do a water change. I just leave it alone for 2-3 weeks and the bones are completely free of all flesh etc. But sometimes I do put a whole mummified animal in that is only left with bones and minimal skin/fur after vultures have stripped it of flesh, guts, eyes, etc.

When you do put in something that still has a lot of flesh say like a skinned and gutted animal that still has a lot of flesh, tongue, eyes, brain etc - you will need to do water swap outs every week or so and this will take longer that it needs to. Making more work for yourself in the end. I've absolutely found the bones being more greasy this way as well.

You NEVER want to put in a whole entire animal. You are creating a nightmare for yourself, truly. Creating so so much work for yourself and absolutely the top level worst spelling situation. The animal with bloat as it fills will gasses and float for starters.

But to be clear this is a VERY bad smelling process. If it smells like putrifying flesh, you're doing it right ha! As the flesh falls off the bones the water will become nasty/smelly. If you're a week in and actually seeing floating pieces of fat, fur, flesh etc - pour HALF of it out and replace with new clean water. You never want to pour all of it out because you want to keep your bacteria working friends but get rid of the stuff in there that's smothering them or slowing the process like a lot of fat. Repeat this process until all you are left with is bone.

IMPORTANT TEMP NOTE - Maceration greatly slows in colder weather because the bacteria die off or can't even get started. Likewise if you were to leave your maceration in full sun there's a good chance it will get too hot and you kill it, causing you to have to start over. It doesn't need to actually be hot to work, warm outside temperatures is fine out of direct sunlight. I sometimes keep a 5-gallon bucket with lid on INSIDE my work studio over the winter. I don't smell it at all and it is still working with my studio staying around 65 degrees!

You also want to do this whole process the way I suggest here to keep from bacteria die off which can cause bone discoloration and from gravewax to occur.


Freshly macerated and rinsed bones, ready to degrease, sanitize and whiten.

This will be very putrid smelling process as you can imagine rotting flesh is. I advise wearing latex or  nitrile gloves when handling these remains until it is sanitized in the final step. I also wear a respirator if it is exceptionally bad.



IN REVIEW - ORDER OF BONE PROCESSING STEPS:

A) DEFLESH - Either nature clean or macerate your remains. I often use a combination of the two. Letting nature do as much as it can for me in my bone cages then I macerate the rest. (Yes, there's more ways to deflesh but I'm just discussing these options here.)


Maceration bucket getting started with mummified fleshy wild boar and deer bones.

B) DEGREASE - Some people like their bones very grease free or only mostly degreased. It varies for me from bone to bone and what they'll be used for. Bones found in the woods or out in a pasture rarely have much grease left in them if at all as the microorganisms living in the soil have already done that for you along with the rain and sun. If you try to degrease them you could end up destroying them. I can tell by the sound, smell, weight and feel of bone how much grease is still in it. You will learn this over time. Many people think any yellow/brown color in bone is grease which is absolutely not true. Often times it is actually soil staining. Especially if it is uniform in color rather than pooling in thicker bone areas as grease does. 

C) WHITEN - Do the regular 3% hydrogen peroxide bath until desired color. Some people like their bones brown and stained. But remember if you are going to be handling them and especially if you are going to be selling them as jewelry, in art or for collections you don't want your anyone else getting sick! At least let the bones soak for a couple days. If you see a lot of bubbling when you drop the bones into the bath they are still very soiled or unsanitary.

Speaking of sanitary, I shouldn't have to say this but I've heard of some people mixing their bone processing tools with their kitchen items. No, no, noooo! Do you want to get sick? I always keep my foodstuffs and bone processing tools, containers and such separate. I don't even wash or store them together. Be smart.

And come on people, don't let your pets chew on your bones or drink the maceration water. Seriously. Would you let your children?!?

Lastly, all of these processes take time. You must have patience if you want strong, properly cleaned and sanitized bones. I've found many people just don't have the patience for processing themselves and buy them instead. Or maybe they don't have a strong stomach...haha

I hope this was helpful!

Here is an additional HowTo blog post about maceration - The Mathematics Of Maceration - A HowTo Guide For The Impatient