A HowTo Guide For My Crock Pot Methods

IMPORTANT EDIT: Too many people are misunderstanding this post and I actually considered deleting it because of the messages I've been getting. This is an absolute LAST RESORT process for LARGE BONES with tough stuck on skin/ligaments only after maceration has already been done. This is NOT for a fast and easy way to clean your remains. You will destroy your bones quickly that way! Especially if they are small/thin. They will crumble in your hands and you will be very sad. I don't want anyone getting mad at me for misunderstanding this post. SO YOU'VE BEEN WARNED! Stick to maceration and be patient. For strong solid bones it take a lot of time, period. I have been processing bones for over 30 years, I know this stuff very well. If you are new at this do not do it.

I've mentioned here previously in my 'Bad Words: BOIL & BLEACH' post that my last resort for removing tough stuck on ligaments, skin and etc from bones is a crock pot. But I didn't really go into much detail. So this is my instructional guide for that.

This crock pot method is one of my own invention. I've never met anyone else that does it. It has worked well for me since the early 90s when I first started using it. I've further mastered it since and figured out other ways to use it for bone processing tasks... and I've used the same trusty crock pot all these years.

DEFLESHING:

When I have a really stuck on flesh mass, ligaments or something similar that maceration has not removed I use the crock pot as a last resort to remove it from the bone. Most of the time it works within hours but in tough cases I've had to leave it overnight or a full 24 hours.

I like to add a metal veggie steamer/strainer to the bottom of the crock pot to minimize the bones/teeth actually touching the hot ceramic pot since it is this extreme heat that can damage them. But if you can find a metal strainer that fits in your crock pot that won't rust, that will work well too.

This method is also a good way to carefully clean smaller more fragile bones that may start to break down during maceration. Put them in a metal screen style tea strainer if they are that small to keep from losing them, or another smaller metal strainer that will fit into the crock pot.

The reason I do this in a crock pot and not stove top is because I like to carefully regulate the temperature. Stove top simmering always seems to eventually boil. The lowest setting on my crock pot never boils. I've discussed why boiling bones is bad in my 'Bad Words: BOIL & BLEACH' post.

I fill the crock pot with water well above the bone and put it on low and replace the lid. Being sure to top off the water as it evaporates. Best part is that there is nothing to do. You just put your bones into the crock pot and go do something else. Just like when you use it to cook dinner.



Vultures had literally just pulled the outer skin off this opossum so I decided to do a slow simmer in the crock pot instead of maceration. This worked very quickly with the flesh still so fresh/soft.

There's really not much of a need to add anything to the water. The slow constant heat alone will get the toughest dried on mummified skin off of anything. Often overnight. Sometimes I pour out what has cooked off overnight, add new water and start again... if it is something really fleshy like a mummified head.



These turtle skulls started off whole mummified heads before I added them to the crock pot. The process is so gentle that even the keratin sheaths (or rhamphotheca) that covers the upper and lower turtles jaws were unharmed.

DEGREASING:

If the bones seem very greasy I just add a little dish soap to the water and it helps the natural fats out of the bone and rise to the top. That's the only additive I've ever put in the water with the bones. But grease will still come out of the bone without you even adding soap to the water! This is why I say to add water well above the top of  the bones you've added to the crock pot. The grease will float to the top where you can easily spoon it out of the water.



These partial coyote skulls were quite visibly greasy so I put them in the crock pot overnight with some dish soap.



The next morning a good amount of grease was at the top of the water.



To easily remove the grease from the crock pot so it doesn't get back onto the skulls when removing them I just scooped it out with a spoon. Doesn't get any easier than that. Remember as I discussed previously in my post 'Bad Words: BOIL & BLEACH' that boiling bone will draw the grease further inside the bone. So don't do that to remove the natural fats in animal remains.

SOFTENING BONE TO REMOVE TEETH:

Another thing I use the crock pot for it to soften bone so that it is easier for me to remove teeth. This worked well for these wild boar mandible fragments.

The bone became soft enough after a couple days for me to use pliers and wrenches to carefully smash and break the mandible apart and extract the teeth.



Much more about this at my 'Extracting Teeth From Bone' blog post.

My crock pot method works beautifully. Very low maintenance. Rarely any need to scrub anything from the bones afterwords. I've never even had any need to find another method. I do wish though that crock pots came MUCH LARGER...haha

I hope you enjoy my HowTo blog posts. For most of the time I've been collecting and processing bones the internet was not yet around and this info was not commonly found in books either. So I've had over 30 years of trial and error figuring out these things on my own. I decided to save everyone some time that comes across my blog and let them in on a few of my trade secrets. And hopefully keep some bones from being destroyed in the process.

The Mathematics Of Maceration - A HowTo Guide For The Patient

I am constantly being asked how long maceration takes and replying "There is no set equation". So I thought it was time for this blog post for some clarification.

It takes as long as it takes. There are a lot of factors that can change the amount of time from start to finish. Time of year, location, size of remains, amount of remains, type of remains, how much flesh/hide is on remains, etc.

Maceration is my preferred method of cleaning bones of flesh, ligaments, soil, etc. It is one of the most gentle methods to use if you want strong, solid bones as the end result. It is literally a form of rotting or putrefaction. Where bacteria removes proteins from the bone. Simply by putting the carcass remains into a sealed container of water.

But it also takes patience. Lots of it. Here are images to explain.



Be safe, be sanitary! I always wear latex gloves when handling the early unsanitary steps of bone processing. Likewise, I prefer to wear a respirator when switching out maceration baths and pulling off tough stuck on skin and hide. That way I can work with it more slowly and carefully rather than rushing it because of the smell.


(click for larger image)

First Image - Nature/insect cleaned deer and wild boar bones with minimal amount of flesh/ligaments/etc. Added to maceration tub. Was filled to the top with water. Then tight fitted lid was replaced. You don't want any big chunks of flesh or pieces of hide/fur/feathers in your maceration tub. Try to remove as much as you can before you begin this process.

Second Image (top) - 3 weeks later the water in the tub was a rusty brown color. This is a good thing. Means the bacteria are doing their work to remove the fleshy bits. Water was NOT switched out that entire time. Sometimes I prefer to switch out the water now and then as it gets cloudy... say once ever other week. Depends on what I have soaking and time of year. As the oils rise to the top of the water and flesh falls off to the bottom, the water will become incredibly nasty/smelly. As it does, pour it out and replace with new clean water. The rule is that once the water is clear, you're done.

When it is colder it slows down the process. It will work best if kept in a warm location. I've read that maceration works best between 35°C/95°F and 50°C/122°F. I'm located in Florida so I can just leave my big maceration tubs sealed outside year round. The process just really slows down through the Winter.

Third Image (bottom) - There are still some meaty bits on the bone and some of the vertebrae were still attached. So not done yet. Threw them back into the bucket and added water and lid again. Takes as long as it takes. Bone processing takes patience. If you are impatient get several projects going in rotation at once. I usually have all stages of the bone cleaning process going at all time. If you are always messing with the bones or worst, cooking them because you're impatient... you are likely damaging them. True story.

Here's another maceration batch example image:



I left this similar batch of bones soaking for at least a month without switching out the water once. It wasn't planned, I was just busy and forgot. The water had turned this amazing blood red color. The bones rinsed off quite nicely and didn't need to macerate any longer.

They did however smell pretty awful. So I put them into a fresh batch of water with some dish soap to help get rid of the smell and to further degrease the bones. Larger bones like these deer/wild boar pieces take a bit more time to degrease. Some animals also seem to have more grease saturated into their bones.

Next step is to sanitize and whiten. Remember, do NOT use chlorine bleach, only hydrogen peroxide. Check out my blog post Bad Words: BLEACH & BOIL for more bone processing HowTo info about this.

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PRECAUTIONS ABOUT MACERATION ADDITIVES

Some people do use cleaning agents/detergents in their maceration baths to accelerate softening of the flesh and/or encourage grease to come out of the bones. However, I do not. In my experience adding anything manmade to the mix is only chancing weakening the bones. So the below info is just for informational purposes. I do not endorse any of these products.

Sal soda (sodium carbonate) is a water softener that some people use to accelerate softening of the flesh.

Biz is an enzyme-based bleach. Which makes me hesitant to use it personally. But I've had others tell me it works for them.

Oxiclean is a detergent and bleaching agent. I was told it does NOT work very well. Not only did it not get the fatty residue off of the bones but it also DISSOLVED some entire bones!

Borax (sodium tetraborate) is a laundry booster and will turn your bones to mush. So do not use it!

Vinegar will literally turn your bones rubbery. You don't ever want to use it in any step of processing.

The way maceration works is that living bacteria is in the water removing the flesh from the bone. If you put any sort of additional chemical or soap in the water that would likely kill bacteria rather than promote their growth. That just seems counteractive to me.

If you read through the maceration HowTo guide of one of today's biggest bone companies that specializes in selling high quality bones, you'll see they just use water. Nothing more. That to me says all I need to know. See for yourself, here is The Bone Room.

I'll just close with that thought.

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 process called the European skull boil method. Which is very poorly named. You want your water to simmer, not boil.

Boiling causes fat to soak into the bone. Leaving you with a greasy and yellowish bone. Some grease can be removed with ammonia and certain industrial solvents but they cannot remove deep grease. I absolutely NEVER use any harsh additives, cleaners, solvents in my bone processing. In my experience the more unnatural processes you put the bones through the greater than chances you are lowering the quality of them.

So instead to degrease you want to put your bones in a bath of water and dish soap. Some people swear by Dawn, I've honestly never even used it. I find the generic works just fine. The grease will slowly come out of the bone and float to the top for you to scoop off. This is a slow process which can take weeks or even months.

Boiling can also weaken and break bone that has already started to decay. 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 must. If you see bubbles, your water is too hot. Though, I personally only use this method as a last resort to remove tough ligaments and hard dried on flesh. I rarely do it on the stove top because I like to carefully regulate the temperature. Though sometime for things such as large skulls I have to.


Large wild boar skull doing a quick simmer to clean before peroxide bath.

I normally use a crock pot, which larger bones won't fit in. I fill it with water well above the bone and put it on low. Being sure to top off the water as it evaporates. This crock pot method is one of my own invention. I've never met anyone else that does it. It has worked well for me since the early 90s when I first started using it. When I have a really stuck on flesh mass, ligaments or something similar I use the crock pot as a last resort. Most of the time it works within hours but in tough cases I've had to leave it overnight. Also, another trick I like to use is to add a metal veggie steamer/strainer to the bottom of the crock pot to minimize the bones/teeth actually touching the hot ceramic pot.


Vultures had literally just pulled the outer skin off this opossum so I decided to do a slow simmer in the crock pot instead of maceration. This worked very quickly with the flesh still so fresh/soft.

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 to no avail.

To sanitize and whiten bone use regular household hydrogen peroxide (H2O2) that you can easily and inexpensively get ahold of at the grocery store, dollar store or drugstore. Do a 50/50 bath with water just above the bones in a loose lidded plastic container to reduce evaporation. 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.

How long? Just keep the bones in this bath until they are the color you want them. This is a personal preference. Note that the bone will dry lighter than it looks wet. This process can take days or weeks. Although if you leave it too long it will eventually make the bone brittle. But this usually would take months for medium sized bones like say of a raccoon. This is a very safe process for most bones if you properly follow my steps. When done whitening, rinse the bones in water then lay out to dry in the sun on towels or dry inside with a fan on. I put towels or paper towels under the bones to help pull moisture out. Be sure the bones are dry before you put them in a sealed container for storage or they may mold.


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. Do not use a metal container with H2O2. Use plastic or glass. 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.

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 I think 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!

Note that some staining will not come out especially if bones were decaying on the forest floor for some time. Remember, you want to be sure the bones have already been degreased and cleaned of all flesh/dirt/etc before putting into the peroxide.


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. 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.


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 really dry you may be able to cut off parts with scissors. Then put the animal remains in plastic lidded container fully immersing it in water. This is rotting process. Involving the living bacteria that break down the flesh on the bones. As the oils rise to the top of the water and flesh falls off the water will become nasty/smelly. As it does, pour it out and replace with new clean water. Repeat this process until all you are left with is bone. Note, maceration greatly slows in cold/er weather because the bacteria die off.


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

This will be very putrid smelling process as you can imagine rotting flesh is. I advise wearing laytex 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) CLEAN - 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 then I macerate the rest. Also, if after I macerate and find I still have stubborn remains not coming off of the bones I use my crock pot method.


Maceration bucket refreshing with wild boar, deer and cattle bones soaking.

B) DEGREASE - This is really a personal preference. Some people like their bones grease free or only partly degreased. Some don't bother with this step at all. 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. Some people like to leave their bones outside in a sunny spot where the rain and sun will naturally degrease them. I can tell by the sound and weight of a bone much of the time how much grease is still in it. You learn this over time.

C) SANITIZE & WHITEN - Do the 50/50 bath with water and hydrogen peroxide 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 getting sick! At least let the bones soak for a day. If you see a lot of bubbling when you drop the bones into the bath they are still very 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 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