Wednesday, May 2, 2012

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.

Opting Out Of Huffing Death

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.

The Mathematics Of Maceration - A HowTo Guide For The Impatient
(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:

That Gore Cleaned Up Nicely - That's Actually A Bright Red Bacteria & Not Blood

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.



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.


Necrolord said...

This may be a stupid question but, where do you dump your maceration water?

Jana Miller said...

That's not a stupid question at all! It is likely full of nutrients your plants would love for starters. So you could gently pour above your outdoor plant's roots. You could also pour it into your compost. Or just dump it somewhere in you yard far away from chances of it getting back into your water source. I have my own well, so that's important to me. It smells pretty bad so if you live close to others dig a hole and pour it in, cover with dirt and spray down any spillage.

NudasVeritas said...

What kind of filter do you use? Is it just regular carbon filter?
Because when I was talking to people at home they thought I should purchase in some sort of ammoniac filter...

Jana Miller said...

Since I did this blog post back in 2012 I've upgraded to the 3M 60921 Organic Vapors & Particulates Respirator Cartridge. The cartridges I'm wearing here were not working for all of bone dust I work with in my art. These new ones cut out all scent of decay as well. You can see my wearing it here:

Rae Martin said...

I feel like this is a dumb question but what water do you use? Is it tap water? Or would using lake or river water speed things up?

Jana Miller said...

Just use plain tap water. No telling what might be in other water like insect larvae that could damage the bone.

Scavenger said...

Is it really that important to macerate/degrease before using hydrogen peroxide? Can I skip that step even if the bones are a little dirty or greasy, or should I just be patient?

Jana Miller said...

Scavenger - Without seeing exactly what bones you are working on I can't really answer that question well. If there is anything left of the animal on the bone it must macerate. The hydrogen peroxide bath will not remove any of that. If it is literally just dirt try to get as much of it off before the peroxide bath. No need to macerate in that case. Degreasing is really just a matter of preference. If you don't mind it, no need to degrease.

Scavenger said...

Thx, that answers my question.

mooshi said...

hello....just found a mummified parrot. it still has all it's feathers but I'd like to macerate it. will your technique work? how will I keep it from floating??

Jana Miller said...

I really hardly ever post anything anywhere in general about birds because of legal issues. Most birds you're going to come across in US/Canada are illegal to have any part of dead or alive because they are Migratory Bird Treaty Act protected species. If you were to macerate most birds you're likely going to end up with nothing but a stinky pile of mush. To process birds, rodents & small reptiles/amphibians you can't really macerate like larger medium sized animals. You literally have to carefully remove the feathers, skin & muscle with surgical tools, tweezers & scissors as best you can. I rarely do this myself because it is so tedious. If it is mummified it may be even harder to accomplish. Or you can soak a while in water & if you're lucky you can carefully peel away the skin from the bones & just hope that most of the muscle was already eaten away by carrion insects. I'll have to make a blog post about this sometime for sure. As well as a longer post about legal issues related to bone collecting.

raideraider said...

I came across some bones about a month ago (deer bones) theyve been macerating for about a month and have been in an hydrogen peroxode bath for two days without a whole lot of improvement. The bones are still dirty looking. Do i need to put less in the hydrogen peroxide bath and do fewer bones at a time?

Jana Miller said...

raideraider... For really fresh/raw bones that you've just macerated that there is a large quantity of and/or they are larger in general you'll have to either do the peroxide bath w/less bones and/or change out the bath more often. If the peroxide bath is cloudy it is likely no longer working. Plus they likely need to be degreased which takes a long time for larger bones. Larger being over med sized animal like an opossum. Good luck!

Anonymous said...

Hello, I have a quick question.

I have six ram's heads macerating in a closed plastic grain barrel. I was wondering whether or not the bacteria will begin to break down the horns, as they are keratin and entirely different from antler. Should I be keeping the horns out of the water? Or checking to pull the horn caps off? I've simmered skulls in the past and pulled horn caps off after a few minutes of cooking but I've never been happy with the results of the skull. I didn't know if they would even come off when doing cold water maceration.


Leanne Sykes said...

thank you so much for writing this up. It's been so helpful! I found a fox hit by a car recently and I cannot freeze it or skin it so cold water maceration seems to b the way to go as I want to save what I can from the animal. When you say a tight lidded container, is air tight okay? Can the bacteria still thrive in this condition?


Jana Miller said...

Hi Leanne!

Your concern here would not be the lid but how much flesh/fur is still on the fox. But yes, the tighter the better. First you need to either hand skin and deflesh it yourself or let nature take care of it in the safety of a bone cage where scavengers can't run off with the limbs. Only after that should the maceration process begin.

Most importantly, no… you can not just drop a whole freshly dead animal into a tub of water to macerate.

You want as much flesh, muscle & especially fur/feathers gone before starting the process. Or you will just find yourself with a horribly stinky bloated carcass that's barely decomposing. And would take months upon months to decompose down to only bones. Which will likely destroy the bones in the meantime. Feathers and fur will barely decompose during maceration process so you really want to try to remove as much of that as possible before maceration.

Good luck!


Jana Miller said...

Hi Erica Heath!

The horn sheaths will break down much slower but will in fact be ruined in the longrun if kept in maceration. So you want to try to pull them off of the skull as soon as you are able (if you are able). Normally the sheaths are prepared separate from the skull once removed. I've never had the chance to process any kind of raw animal head with horns yet but I have cleaned up many that were not properly processed. And am familiar to hooves breaking down if left in maceration too long. Which is very similar.

Good luck!


Casie said...

Hi Jana - Thank you for your very helpful site.
So, I am in the process of macerating the head of my femur bone and I have to admit I wasn't prepared. I thought I'd be picking up a white shiny bone, but instead received a brownish bone with my tissue still attached soaking in embalming fluid. I managed not to throw up, and I have it soaking in water on my patio. My question is when I change the water, pull off the flesh or anything else I might do, if I wear gloves and a regular mask such as the one a manicurist might wear, am I putting myself at risk for…..anything? I appreciate your advise/comments. Thanks much!

Jana Miller said...

Hi Casie..

First off, I'm confused about your comment about having a femur in embalming fluid? Embalming fluid has no part in processing anything for the bones. You should macerate to deflesh, then move on to a peroxide bath, then you're done. If you did actually use embalming fluid though, you can't likely macerate it now.

As for your sanitary concerns, I have a whole blog post on that topic here - BONELUST BONE PROCESSING Q&A: I want to start collecting bones/animal remains but I'm concerned about disease. -

Stay safe… jana

Donna T said...

Hi Jana -

Aha! Thank you for your info on embalming fluid. When pathology released my bone to me, they had it soaking in this fluid. I was worried that this might has slowed down the maceration process but didn't think it would stop it.

Thank you for your time.


Jana Miller said...

OK WOW it is actually YOUR own femur! I did not know that. I can't believe they let you keep it, amazing. Anyway, it was likely given to you in formalin to preserve it as-is. It won't likely macerate as the bacteria needed to deflesh it would never grow in water that any kind of chemical was in. You're likely going to have to just hand cut/pull the flesh/etc off by hand yourself. Don't try using heated water in any way either. Would damage the bone. Good luck!

Donna T said...

Yaha, its my bone and thats why I was sort of nausiated when I saw it at first. I wasn't expecting to see any of my flesh on it. Yikes.
They usually won't release the bone, you are correct, but I had a friend who is a funeral director pick it up for me. The glitch is that anyone can get any thing that is removed in surgery, if your religion (mine does not) mandate that you have to be buried with all of your parts. Jewish religion is big on that. So like I said, I was expecting this pretty white femur head and I was going to pop it in a plexy glass case and put it on my shelf…. I want to get a good mask and then I'll do as you say. It's still a bit smelly from the embalming fluid so I'll wait for a mild day, so I can do it outside. Pretty cool to have my bone and if it comes out good, I'll post. Thanks a lot for your time and your necklace looks beautiful. Do you sell your jewelry on line?

BlackPlague321 said...

Hello! Me and my friend have been really into Bone collecting lately. I found a squirrel skull and he's soaking in some H2O2 right now. But I was wondering, after the bath and he's all dried up, could I use clear nail polish to protect the whole skull? If not, what could I use instead?
Thanks in advance!


Jana Miller said...

Hi Marcus! There honestly isn't a need for you to coat the bones with anything. I very rarely seal my skulls/bones myself. I also do not like them shiny though. But if you prefer them that way you can just clear coat them with spray paint.

Kira Cattan said...

Hey Janna,

Today I got...well, not really gifted, but I was walking home and found a recently *less than 2 hours* deceased crow. No flies, no bugs,nothing. I wrapped it up and brought it home.
I have the wings, legs, and the tail spread drying out in salt. I also did the same with the tongue.
Would it speed up the process if you take the skin off the head?

I'm new at this so any info I can get is greatly appreciated.


Jana Miller said...

Hi Hira! You need to be VERY careful with birds. I don't process bird remains very often because it is illegal to have any part of a Migratory Bird Treaty Act protected species here in the US.

It is illegal in US, Canada, Mexico, Russia and Japan to even possess bird remains of species listed on the MBTA. We can not have or sell birds, feathers, bones, eggs, or even nests from anything on that protected list. Likewise, you could be fined up to $15,000 and/or do jail time for having/selling them. So be careful.

List of species covered by the MBTA -

More info -

Most of the birds protected by the MBTA are not endangered. They are very common and abundant. But that was not the case when the MBTA was created back in 1918. Many common birds were being wiped out into extinction from people hunting them and collecting them & their eggs/nests for their collections. And people using the feathers in fashion. That's the misconception that most people don't understand now. The species that are alive now were saved from extinction by the MBTA. That's why they are so common and abundant now.

Best thing to do is give her a proper burial. Stay safe and sanitary!

Kat Aragon said...

Hi! I have a question. I have three cow tail vertebrae in a tub of water and when I dumped the water, one of the vertebrae looks like its fallen apart. Is that normal? Nothing else is in the tub other than water and the bones. The bones were from some cuts of beef used to make ox tail soup, so they were boiled beforehand. Not sure if that might have anything to do with it.

Jana Miller said...

Hi Kat! A bone that large and solid would not fall apart during maceration. It was either sawed through by the butcher or damaged during boiling. See my blog post - Bonelust: Bad Words: BOIL & BLEACH -

UNKN said...


Great work and information!

I have 2 sections of elk vertebrae with each section containing 4-5 vertebrae that are still connected with ligament, tissue? The bones have no other skin or muscle material besides what's holding them together. The cold water maceration will decompose the tissues and separate them all correct? I would like to display them together though for the end product, is there a glue or something you recommend for keeping bones together?



Undermedicated Visions Photography said...

Hi Jana, thank you so much for sharing your knowledge & experience here! I have a few questions... With cold water maceration, does the specimen need to be skinned? I also read somewhere about ground maceration, does that simply means burying? Also, do you know of any good online articulation guides as well as any places that sell replacement teeth for dogs? Any information you can provide would be greatly appreciated!

Sarah said...

Hi Jana, can skulls with antlers be safely macerated this way? Does the maceration process change the color or texture of antlers in any way?

Jeromy Cilley said...

Hi Jana,

I started processing bones (skulls specifically) about a year ago, and I have found your site to have the most information; with your help, I have processed a rabbit skull (a pet that died of old age), a coyote, and a fox (both road kill). I am currently working on a found deer, grey squirrel, and two nutria (strange skulls). And I have a TON of questions. I find that most of those questions get answered with patience, but two still linger: during maceration, should all the teeth be dropping out? the front teeth always come out, but usually most of the rest of the teeth remain in tact - should I be macerating longer or doing something different? Secondly, all of my skulls so far have dark spots, apparently under the bone - is this grease? Should I be degreasing longer? Hopefully these aren't stupid questions...

here are pics:

Coyote & Fox:

Again, THANK YOU for all of your helpful posts!

Aperture Seiruk said...

Hello :)

I'm new to bone preservation and have been experimenting on a sheep's (ewe's) skull. I'm planning to try wood burning patterning on the bone when it is all cleaned and ready for varnishing. However, I'm having some difficulty recognising that 'ready' stage.

I began by removing the flesh from the fresh carcass about 4-5 months ago, hung the head on a hook in a tree and waited until last week to begin simmering and removing all remaining rot. I used a toothbrush and warm water to get as much of the flesh, gelatin-like substances from around the eye sockets and inside the nasal canal removed as possible, however I now have a problem.

After simmering and scrubbing, I am still left with black discoloration that seems to originate from within the nooks and holes of the skull itself. These black sections seem to have grown during the hanging stage and are remainders of rotting, mouldy flesh that I cannot reach with toothpicks or toothbrush. I am worried this will just smell even worse as I begin to work on the skull during the art design process and ultimately when it is put up for display inside the house. At the end of the entire process I hope to be able to varnish the skull and seal the design in with the bone and the small amount of grease left in the bones, without the tiny pieces of rot inside wearing away at the skull's structure from within.

Are there any tips or suggestions you could advise me with? They'd be greatly appreciated :)

Thanks so much for reading,


Chris Chicoyne said...

Hi! Is The Bone Room's Maceration PDF no longer available? The web link is dead. Thanks!

Jana Miller said...

Thanks for the heads up Chris, here's the new URL which I will update in my blog here -

Mark Mott said...

Hi there,

I was given an old elk skull. It is in rough shape, dirty, some hide and meat still stuck to it, not much mind you but some. I want to get this guy back into god looking shape and after much reading it sounds like maceration is the way to go. Problem I have is that the skull has horns on it so I will not be able to get a lid onto a bucket. Is that going to be okay. I was planning to put the skull in a bucket up to the antlers, fill with tap water and use a fish tank heater set at 90 as that is as high as the heater will go. Thoughts?



Revir said...

My question may be stupid but, can I remove the varnish from skull using Hydrogen peroxide? I've finished my skull using varnish but I like it more without the varnish. I'm quite worried that if I submerged my skull to H2O2 again it will damaged the skull and make it brittle..

Anyway, your blog is very good and informative. I'm glad that we share the same enthusiasm in collecting skulls.

Jana Miller said...

No, hydrogen peroxide will not remove varnish. In fact not much will if t actually is varnish or lacquer. Some paints can be removed with other. Stronger paints and sealants involve acetone. But don't always work. Good luck!

Jana Miller said...

FOR EVERYONE WITH QUESTIONS ABOUT PROCESSING PIRDS: I really hardly ever post anything anywhere in general about birds because of legal issues. Most birds you're going to come across in US/Canada are illegal to have any part of dead or alive because they are Migratory Bird Treaty Act protected species. If you were to macerate most birds you're likely going to end up with nothing but a stinky pile of mush. To process birds, rodents & small reptiles/amphibians you can't really macerate like larger medium sized animals. You literally have to carefully remove the feathers, skin & muscle with surgical tools, tweezers & scissors as best you can. I rarely do this myself because it is so tedious. If it is mummified it may be even harder to accomplish. Or you can soak a while in water & if you're lucky you can carefully peel away the skin from the bones & just hope that most of the muscle was already eaten away by carrion insects. I'll have to make a blog post about this sometime for sure. As well as a longer post about legal issues related to bone collecting.

Here's my blog post - BONELUST Q&A: "How do I get the bones from this small animal?"-

It is illegal in US, Canada, Mexico, Russia and Japan to even possess bird remains of species listed on the MBTA. We can not have or sell birds, feathers, bones, eggs, or even nests from anything on that protected list. Likewise, you could be fined up to $15,000 and/or do jail time for having/selling them. So be careful.

List of species covered by the MBTA -

Jana Miller said...

Mark Mott... I believe I helped you with this on FB some time ago now. I'm way behind on replies here so glad you found me there, haha jana

Jana Miller said...

Aperture Seiruk/Emily... Had you macerated instead you would not have had that issue. I highly suggest macerating instead of simmering next time. It is a LOT less work and leaves your bones in better condition. As for the black possibly moldy spots maybe you'll get lucky and peroxide will remove them. See this blog post which talks about mold. algae, moss and etc:

Whitening Bone Using Hydrogen Peroxide NOT Chlorine Bleach -

Good luck! jana

Jana Miller said...

Jeromy Cilley… Glad my blog has helped out. Sorry I'm just now getting back to your question. It is absolutely normally for the teeth to fall out of most animals when processing them. The gums and roots that held them into place are now gone. Here my blog on how to put mandibles back together. Use that same info for reattaching the teeth:

BONELUST Q&A: "How do I put mandibles back together?"-

As for your dark spots under the skulls, that's likely from the maceration bacteria. Whitening in peroxide should take care of that for you. Here's my blog post about that:

Whitening Bone Using Hydrogen Peroxide NOT Chlorine Bleach -

Your skulls looked really good other than the spots I could see in the rabbit. The photo of the fox and coyote was honestly too yellow/dark for me to tell if they needed a degrease though. Just do the peroxide bath and I'm betting that will help. good luck! jana

Jana Miller said...

Hi Sarah…Maceration may slightly discolor the antlers and even make them greasy. What you want to worry about more though is not putting them into peroxide which will completely discolor them and turn them white.

Jana Miller said...

Hi Undermedicated Visions Photography… Take a look at this blog post - BONELUST BONE PROCESSING Q&A: What should the remains look like to begin maceration?

You never want to macerate a whole animal. You want to try to remove the skin and as much flesh as possible before maceration or you could end up with a bloated mass that is not decomposing.

As for "ground maceration"… there's no such thing. I guess maybe someone is talking about burial processing. Which I honesty highly suggest against due to bone loss, soil staining and rabid bone decay.

As for replacement dog teeth. The closest you might find are coyote or fox teeth and carving them to fit.

For articulation I suggest by friend Lee Post. Nobody has better articulation guides out there that you can buy -

Jana Miller said...

Hi UNKN… I'd use the same glue mentioned here:

BONELUST Q&A: "How do I put mandibles back together?"-

Richter said...

good day, I got a horse head, unfortunately it was preserved in formalin since I got the specimen from our veterinary anatomy class and I decide to clean it. Will maceration still work on this???

(skull was not cut at all, so all meat is still inside such as brains and cartilages. I've already removed most of the muscle)

Jana Miller said...

Hi Richter... The bacteria is not going to be able to grow in the water or on the specimen. Your best bet is to get the flesh off under VERY low heat by hand keeping a very close eye one it. Keeping in mind that any kind of head can compromise the bone structure. especially do not boil. I'd skin off as much as you can by hand first. Good luck! jana

Alison Welsh said...

Hi Jana,

Last June I found a dead Fisher on the side of the road and buried it in my backyard. I dug it up today and found the skull (what I'm after) free of all flesh/fur/tissue. It does seem to be a little oily/greasy though.
I have gone over all your posts but just can't seem to decide what to do next. I am willing to macerate, but I'm wondering if it is necessary and if it will even work considering I am up in Canada and it is still quite cold here. Can I just wash it off and throw it in a peroxide bath? What happens when you do that to greasy bones? Should I attempt to de-grease it? Thank you in advance for any input!

Jana Miller said...

Hi Alison... I never do burial processing so I'm not 100% sure how to answer your questions. I will say though that if there's zero flesh maceration won't do much of anything. I'd probably go ahead and give it a good rinse/scrub then a peroxide bath. You can always degrease after that if needed. Good luck! jana

Joey said...

Hi Jana,
I got a deer skull with antlers attached that looks to be processed (there isn't visible flesh attached) However, on the underside of the skull there is still a noticeable smell from about a foot away. If there is flesh it would be down in the nooks and crannies around the teeth, etc. Does this mean the skull needs additional maceration or would hydrogen peroxide kill the smell too? Thanks for all the info and help!

Jana Miller said...

Hey Joey... that's a tough one without seeing the skull in person and know the whole processing history. Stink could be from maceration and just need a peroxide bath (don't get the antlers in it, will bleach out color!). Or it could still need to macerate more. Or could need a degrease. It is absolutely going to smell very badly after maceration. So try peroxide first. Good luck! jana

wild_warrior said...

I read above that maceration water is good for plants, is it okay to put in my vegetable garden?

Jana Miller said...

Yes that's OK wild_warrior, I put it in my own veggie garden. The plants love it. Just be sure not to splash it on the plants.

Laine Krassner said...

Is it possible to macerate bones for too long? It was never particularly hot, weather is always between 70-30 degrees. I left a deer skull and spinal column in the container for probably 8 months without checking on them. When I dumped out the water today, they were very clean, so that's a success, but I also think they have degraded slightly. They seem more porous/weaker than they were when I put them in.

Is that normal? Or I though maybe it could be that the tap water around here has a small amount of bleach in it (for treatment)...but the mace ration process was successful. There wasn't a ton of remaining flesh/tendon on the bones when I put them in, so the water wasn't too gross, but it seems like bacteria were thriving enough to clean up...


Laine Krassner said...

Can bones macerate too long? I had a deer skull and spinal column in the container for probably 8 months, without checking on them. The weather is always mild (between 75-35 degrees) and I used tap water. The bones were clean when they came out, but they seemed weaker/more porous.


Zuhal Yorgancioglu said...

Hi Jana,
So I cleaned almost all the tissue from a calf's skull and then let macerate for 10 days without disturbance. All the remaining soft tissue came right off, save for bits of fat stuck in tiny crevices around the jaws, and a bit of tissue right at the beginning of the spine. I put it in a peroxide bath (59% concentration, but with around 8/1 water/acid ratio) for two days, washed it out with plenty of water, then with soap, and set it to air out.

The problem is that it still smells awful. I've used peroxide for smaller animals such as cats and squirrels, and they never smelled this bad after a bath... (I can still smell the rotting tissue)

Would you say this is the case because of the bits of fat still stuck here and there, because the peroxide wasn't strong enough, or because I didn't let it soak long enough? And do you know how I might be able to get rid of the smell?


Mitchell Barazowski said...

I had a mostly clean calf skull and turtle shell which I left outside for a few months then macerated to remove the remaining bits of flesh. They cleaned up really nicely but started to separate at the seams as if the bones shrunk. Is there a way to prevent this? Would a clear coat help keep the bones together for the future?

Jana Miller said...

Mitchell Barazowski, they came apart where they were not yet fused. That's normal for some bones. Especiall in juvenile animals like the calf. You'd just need to carefully piece them back together when done processing.

Jana Miller said...

Zuhal Yorgancioglu, bad smell usually means it need to be degreased, had flesh still on it and/or it need a peroxide bath. Longer peroxide bath in your case possibly. The fat certainlly will smell bad so I'd star with trying to remove it first. 10 days is a really short amount of time for maceration for me personally. Good luck!

Jana Miller said...

Laine Krassner, It sounds like possibly it could have started to decay the bones themselves. The bacteria will keep eating away at whatever is available. When the fleshy bits are gone, it starts in on the bone.

Gregg Kusumah-Atmadja said...

Greetings. I want to use a cold water maceration to clean a deer's rib cage and spinal column. Will everything stay in tact afterwards? Is there anything i should watch out for?

Jana Miller said...

Gregg Kusumah-Atmadja - Maceration is to get rid of everything other than bone. So no, the deer spine will NOT stay together if you macerate it.

Anonymous said...

Hi! I acquired a goat skull last June and I started doing a cold water maceration with biological washing powder. I got very busy and could not finish the process with changing the water until today. The skull didnt contain a whole lot of tissue and I already removed the antlers beforehand, but I found that the jaw bone had become brittle and almost broke in half and the bones have become slightly discolored. This is my first time doing this and I'm very uncertain as to what's the next steps I should take before I end up accidentally worsening the rest of the skull and antlers. Can you offer me any advice on how I should go about this? Thank you!

Jana Miller said...

Hi Rashika, please note in the above blog post the section that starts with - PRECAUTIONS ABOUT MACERATION ADDITIVES. I've never used biological powder in any of my processing so I would not even know where to begin. I know Jake of Jake's Bones online uses biological power. I would check out his blog and perhaps try asking him. Normally maceration is done in a couple weeks so it sounds like you've possibly macerated too long and the biological powder weakened your skull. Good luck.

Catherine Cimino said...

Hi Jana, how do you remove the brain before maceration? Or is it necessary?

Jana Miller said...

Hi Catherine... I let the maggots remove the brain for me before macerating. See my bone cage blog here -

Thomas said...

Hi Jana,
Beginner question here. I harvested a small Barbary Sheep and decided I would try to make a European mount myself. I got the horns off OK, and put the skull in a cooler with an aquarium thermostat. I let it go a couple days, pulled some flesh off, etc. Today (day 5) most of the big chunks of flesh are off and it's breaking down nicely, but I noticed the sutures on the front of the skull are coming apart. Possibly because I didn't remove the brain before water maceration, I don't know. Anyway, what would you recommend? Continuing on, degreasing, whitening, and gluing back together at the end?

Jana Miller said...

Hi Thomas, I normally let the maggots remove the brain for me before I macerate. The sutures in the nasal area are not uncommon to come off during processing for goats/sheep. It will be easy to put them back on with a tiny dab of white school glue. If it is the suture on the top/front of the actual skull, yes the brain expanding could possibly be doing it. I really can't say without seeing what's going on. Some younger animal's skulls are not fused. So that's also something to consider. I'd consider trying to remove the brain then continue maceration, degrease, peroxide bath. Good luck! jana

Thomas said...

My guess, knowing what the animal looked like when harvested (and after reading some of your responses above), is the skull was not completely fused. Pretty much every suture is loose, but only two pieces have fallen off, one nasal bone and the occipital. The brain actually came out within 2 days of maceration. I checked today and it's almost done, there are very few bits of flesh left, but like I said, all the sutures are coming apart. Guess I'll be spending a bit of time gluing it. Cool website, thanks for the response!

tohuwabohu said...

I found an intact deer pelvis with some vertebrae attached that has quite a bit of soft tissue keeping it together. Ive left it in water for weeks and the tissues havent macerated much, although they become pliable and once I let it dry they hardened. Im sure to remove the soft tissues I will have to break the pelvis apart. Can I possibly keep the pelvis as is without removing the tissues for decor or will it rot and stink at some point?

Also love your website, I've learned so much, thank you for all the info so far! :)

Jana Miller said...

Hi tohuwabohu… Maceration should work for this. Sometimes it just takes longer. Deer spine usually take at least a month in maceration for me with optimal conditions. Meaning warm weather. If it is not warm where you are you may need to add an aquarium heather to help the bacteria do their job faster. good luck… jana