Mom Goes Camping

How to Clean and Whiten Animal Bones (Step by Step with Pictures)

how to clean bones using hydrogen peroxide and baking soda

My strange and wonderful daughter has an obsession with bones since she was three years old. She even asked me if she could have my bones when I die.  I said yes, but since we aren’t at that point yet, right now we are gathering all sorts of animal bones and cleaning them. 🙂 

Cleaning animal bones for display is fairly simple.  The entire process can be broken down into three steps:

  1. Start by removing any tissue left on the bones.  The simplest way to do this is to bury the carcass or leave it for insects to clean.
  2. Soak the bones in soapy water to remove grease. Give them a good scrub.
  3. Then soak the bones in a solution of 12% hydrogen peroxide and water.

Some bones can be a bit tricky though — especially when they are from small animals, very large animals, or greasy animals. Below I’ll get into the details of what to do in each step of the bone cleaning process.


Guess what? I wrote an entire eBook about cleaning bones.  It covers a lot more than I could fit in this article, including lots of expert tips and hacks that amateurs can use.  You can buy it here (instant PDF download) for $4.99!

how to clean bones book

Get the eBook here

Jump to:



In order to clean animal bones, you will need the following supplies:

  • Gloves
  • Buckets or trash cans that can hold the bones being cleaned
  • Dish soap
  • Scrub brushes
  • Hydrogen peroxide

Depending on the type of bones and their condition, you might need some other supplies too, such as as power washer, muslin sack, pliers for removing teeth, and ammonia for degreasing.


Important: Never Use Bleach for Whitening Bones

A lot of articles online about how to clean bones say to “bleach” the bones.  You should NEVER use bleach to get bones white.  Why?  Bleach will destroy the structural integrity of the bones.

Likewise, you don’t want to use any laundry detergents for cleaning or degreasing the bones.  These detergents often contain bleach or other harsh chemicals which can destroy the bone.  Instead, you should only use hydrogen peroxide to clean bones.


Where to Get Hydrogen Peroxide

Hydrogen peroxide (H2o2) is the safest and most effective way to whiten bones.  This is what taxidermists use, including the ones at the Smithsonian and other prestigious institutions.

You can use the 3% hydrogen peroxide found in drug stores to whiten bones.  The problem is that this peroxide is very weak.  You’ll either need to buy a zillion bottles of it or do multiple soaks to get the bones clean and white.

To get good results, you want 12% hydrogen peroxide. 

Unfortunately, not many pharmacies stock concentrated hydrogen peroxide in that concentration. Sales are often restricted to people who work in laboratories.

If you can’t find 20% or higher hydrogen peroxide, you can use hair developer instead.  I’ve since lost my pharmacy connection, so now only use hair developer for cleaning bones.

There are two types of hair developer:

  • Clear Developer: This is the exact same thing as the hydrogen peroxide you’d get in a pharmacy. It will bubble up nicely and works great for cleaning bones. Get 40 volume clear developer here.
  • Cream Developer: This has some emulsifiers added so it is creamy and thick.  Some hardcore taxidermists won’t use it, saying the emulsifiers could mess up the bones.  It also won’t bubble up like clear H202, so it isn’t as good at getting stains out from deep within bones. However, because cream developer is thick, it can be painted directly onto bones. That makes it great for spot whitening, or for whitening skulls with horns.  You can just paint it on around the horns. It does dry quickly though, so you’ll need to cover the bones with some plastic wrap. Get 40 volume cream developer here. 

Hair Developer Strengths:

Hair developer is listed in strengths by volume. Don’t think that 10v equals 10% though.  The actual concentrations are as follows:

  • 10 volume =3% hydrogen peroxide. Don’t get this.  It’s too weak for good results!
  • 20 volume =6% hydrogen peroxide. 
  • 30 volume =9% hydrogen peroxide.
  • 40 volume =12% hydrogen peroxide. 

You can buy 12% hydrogen hair developer (40v) on Amazon here. It’s the cheapest I’ve found and the strongest hydrogen peroxide you’ll likely find unless you happen to have a hookup at a pharmacy.

hydrogen peroxide 40%

This giant bottle of hair developer (hydrogen peroxide) is 12% and is really affordable for a gallon. Buy it here.


Steps for Cleaning and Whitening Bones

Cleaning small bones is pretty easy.  However, it may take some time -especially if the animal is fresh and has lots of soft tissue on it still.


Step 1: Remove soft tissue

If you have a fresh carcass or rotting animal (like roadkill), you’ll need to use one of these methods to remove the tissue before cleaning and whitening the bones.

*Always remove as much tissue as you can before starting with one of these methods.  It will make the process go a lot faster.  However, if the animal is already rotting, don’t try to skin and gut it.  There’s simply too much risk of contamination. :/


Method 1: Maceration (Soaking)

If your bones have some soft tissue or rotting flesh on them, the (arguably) best way to remove is it is with maceration.  Basically, you put the bones in water and let them sit so natural bacteria can remove the tissue.  When the water gets gross, you toss it and add fresh water.

The downside is that this can take a very long time, potentially MONTHS.  It’s also very stinky and gross.  Because I live in a small apartment without a yard, I’ve only done this with small bones.  At one point, I had 3 jars with dead animals soaking under our bathroom sink! 😮


Method 2: Burying 

Alternatively, you can bury the bones. Bacteria will eat away at the bones (and maybe some worms/bugs will eat it too).  But this also takes a long time.  It can take 3 months for a large animal to fully decompose.

Note that scavengers might dig up bones that you buried.  Even worms/insects can move around bones a lot.  To keep your bones safe, I’d recommend putting the bones in a wire mesh (for larger bones) or a muslin sack (for smaller bones).

Small animals can go in Tupperware containers filled with dirt.  Poke some holes in the container so insects can get inside. The container should to be kept out of rain so the dirt doesn’t turn into clumpy mud.

Alternatively, you can just leave bones outside. Insects like ants will eat away at the tissue.  Microbes will also go to work.  Preferably, put the bones in a wire cage so animals don’t carry them off but insects can still get in.

We found this bat while on a camping trip and took him (her?) home with us.

bat skull

And here’s what the bat looked like after sitting in a dirt-filled Tupperware container for 2 months


Method 3: Soaking in Biological Powder

A faster method for removing soft tissue from bones is to use biological cleaning powders/enzyme stain removing powder such as Biotex (which you can buy here) These cleaners contain enzymes which will break down the soft tissue.  Just soak the bones in a solution of the powder + water until the tissue becomes soft enough to scrape off.

Just like macerating in water, the soaking bones will stink.  Yes, you’ll have to dump the water frequently until the bones actually get clean.  It will be frustrating and gross.


Method 4: Boiling (NOT RECOMMENDED!)

Boiling bones will loosen soft tissue and cause it to fall off very quickly.  However, boiling will cause fat to get trapped inside the bones and they’ll get all white and shiny looking.  Don’t ever boil bones which are already fatty.  This includes: boars, bears, and possums.

If you are impatient, you can SIMMER the bones. Not as much fat will get into the bones if you simmer instead of boil.  Just try to remove as much of the hide and hair as possible before putting the carcass into the water.  These have a lot of oils in them which will soak into the bones when simmering. You’ll then end up with gross yellow spots that are difficult to remove.


While boiling is a no-no for cleaning bones, steaming should be okay.  The steam will loosen tissue quickly.  Since the bones aren’t floating in tissue-filled hot water, the fat won’t absorb into the bones. While I haven’t tried this personally, but Jake of Jake’s Bones uses a baby bottle sterilizer for cleaning tissue from bones.  Basically you steam the bones inside the sterilizer. He warns that it will smell disgusting!


A lot of people put additives like OxiClean into the simmering water.  This supposedly helps break down tissue and also get fat out of the bones.  A lot of people swear by it.  But a lot of other people also say that OxiClean will destroy bones, causing them to literally turn to mush.   It seems to be okay on deer skulls, but probably not okay on fragile bones.  Try this at your own risk!  Or, better yet, be patient and just bury the bones to get the tissues off.  It will take longer but the results will be much better.

boiled pig skull

Isabel got this pig skull as a gift. It was boiled so got all gross, yellow and shiny from the fat that got trapped in it. It was HELL to degrease!!!!


Removing Brains from Skulls:

This is gross.  Really gross.  I’m still pretty squeamish, so I will bury any animal carcasses that still have all their tissue in them.  When you bury the bones to clean tissue, the microbes eat away at everything.  Thus, there’s no need to remove the brain.  The same goes for if you just leave the carcass out for insects: they’ll eat the entire brain away.

However, if you’ve removed tissue by soaking or simmering, you’ll have to get the brain out. It is really fatty and rubbery, so won’t come out so easily on its own.

Here’s how to remove a brain from a skull:

  • Soak the skull to get the brain tissue soft (or give the skull a quick simmer if you aren’t too worried about it turning yellow)
  • Take a wire/coat hanger and start jamming it into the skull.  The goal is to “scramble” the brains. This is something the ancient Egyptians mastered thousands of years ago. 😉
  • Get a power washer and blast into the back of the skull.  Brains will shoot out of the nose. WEAR GOGGLES unless you don’t mind getting pieces of brain in your eyes.
  • Or use a saw to cut off part of the back of the skull and scoop out the brains.  Some skulls (like deer skulls) sit better on their mount when the back is flat anyway.


Hidden Tissue in Skulls 

Be warned that there is a lot of tissue hiding in animal skulls – especially big animals.  For example, there are often giant nerve endings inside teeth.  You will also have nerves going through foramina in skulls. Foramina are holes where the nerves go from the brain to the face.

foramina of the skull

To remove this tissue, you may need to:

  • Carefully remove front teeth with pliers. Wash/poke out nerve endings.  Make sure to reinsert the teeth while the skull is still wet. Otherwise the bone shrinkage might make it impossible to get teeth back in.  Ideally, you remove morals too but these are really difficult to get out.
  • Use wire to poke tissue out of foramina: This is hard to do.  One more reason to bury bones for cleaning off tissue.  Bacteria can get into those tiny holes and remove it.  Soaking bones or simmering won’t get this tissue.
cleaning bones of hidden tissue

This pig skull was boiled.  When I soaked it to degrease it (more on that later), all sorts of tissue started coming out of the foramina.  It just goes to show how ineffective boiling is for cleaning bones!


*For more detailed info on how to remove tissue, read this post


Step 2: Pre-clean the bones

This applies to bones you have found which do not have any soft tissue on them, but are caked with dirt and maybe have moss growing on them.

Use soapy water and the toothbrush to SCRUB the bones clean.  The cleaner they are when you start, the better the hydrogen peroxide will work.

step one in cleaning animal bones

This gives a new definition to brushing your teeth!


Step 3: Soak the Bones in Dish Soap (Degreasing)

If you found the bones in the woods and nature has already “cleaned” them for you, then you can probably skip this step.  However, bones which were soaked or simmered must be degreased.  Likewise, the following animals and bones are notoriously greasy:

  • Possums
  • Pigs and boars
  • Bears
  • Seals
  • Whales
  • Vertebrae


Why do bones need to be degreased before whitening? 

Bones actually have a lot of fatty oils inside of them. If you don’t remove the fats, they will eventually start to rot.  The bones will turn yellow and start to stink.  They might break down completely.   Even if the bones seem white and clean, there might be fat trapped in them which will come to the surface later.  That’s why badly-cleaned bones will turn yellow over time.

Dawn dish soap works great for degreasing. Just put the bones in warm water with a lot of Dawn. If they are really gross, then you’ll need to dump the water and re-soak.

How long will degreasing take?

Some animals have insane amounts of fat in their bones.  You’ll have to degrease them for a LONG time.  Professional taxidermists will use tough solvents like acetone on them and it can still take WEEKS.

You’ll know degreasing is done when there aren’t anymore shiny yellow spots on the bones.  Also, the water will stop getting cloudy when you soak the bones in it.


  • HOT water works best for degreasing.  Some people use aquarium heaters to keep the water hot during degreasing.

Check out how greasy this possom skull is! It had to be thrown away because the fats started rotting the bone. 


Step 4: Whiten with Hydrogen Peroxide

Once the bones are completely free of tissue and have been degreased, you are ready to whiten them.  You’ll need hydrogen peroxide for this.  As I said before, never use bleach for whitening bones.  It will destroy them by making them flaky and brittle.

Here’s how to do it:

  1. Put the bones in your bucket.
  2. Pour in your hydrogen peroxide.
  3. Then top it with water.
  4. The bones will start foaming, which means the hydrogen peroxide is working.  Hydrogen peroxide also heats up when it is working.
  5. Loosely cover the bones while they soak. The H202 will stay active longer this way.

How much hydrogen peroxide to use?

I usually use a ratio of 1:3 hydrogen peroxide to water.  However, the higher the concentration of hydrogen, the faster and whiter your bones will be.

Tip: Try to find a container which fits your bones exactly.  Then you won’t have to use as much H202 to cover the bones.  If you can’t find a suitable container, you can use this pro trick:

  • Line the container with a heavy-duty trash bag
  • Put the bone in the trash bag
  • Fill the container with water.  The water will fill the space around the bone in the bag.
  • Now pour the hydrogen peroxide into the trash bag.

Remember that hair developer works just the same as hydrogen peroxide. You can buy it in bulk here.

container for cleaning animal bones

cleaning animal bones - adding hydrogen

Adding peroxide to the bones

Hydrogen for cleaning bones - starting to foam

The peroxide is starting to foam!

whitening a cat skull

And here’s a cat skull soaking in hair developer + water. This one was done with cream hair developer, which doesn’t bubble as much as clear hair developer.


Step 5: Cover and Leave for 24+ Hours

It is important that you cover the bones once they are in the hydrogen peroxide solution.  The lid will keep the fumes within the bucket and help it work better.  Don’t make the lid too tight though — the bubbling could  make the lid explode off.

Check out the before/after of the cat skull below.  This was after just one round of soaking in 40 volume (12% hydrogen peroxide) hair developer.  If you want your bones to be realllly white, then you’ll have to do several rounds — especially if they were super dirty like this cat skull was (it was half buried in dirt when we found it).

before after cat skull cleaned


*Note about Cleaning Very Dirty Bones

I once made the mistake of not adequately cleaning a very dirty bone. The hydrogen peroxide went crazy on it!  It started steaming and got HOT. I thought it was going to melt the plastic bag it was in!!! You can see in the picture all of the steam coming off the bone.

The message? Make sure you do a really good job of scrubbing dirt off the bones before soaking in hydrogen peroxide!

steaming bone in hydrogen

Check out the steam coming off this dirty bone!

The hydrogen didn’t go as crazy on the second round, but still bubbled a lot.  The bone came out nice and clean.  At least cleaner than how we found it. 🙂

cleaning a hip bone

So many bubbles!

bone before and after

Bone before and after cleaning.  Not completely white, but still beautiful!


Cleaning Very Large Bones

One of the first large skulls I cleaned and whitened was a cow skull.  Isabel’s friend found it for her (what other 6 year old is lucky enough to have a friend who saves bones for her?).  The skull was free of soft tissue, but was still really dirty and stunk badly.  I didn’t realize it smelled so badly until halfway home on the bus.  Sorry to all the people who had to put up with the rotting smell on the 30 minute bus ride! 😮

Cleaning such a large bone presented some problems:

  • I literally could not find a plastic container large enough for soaking the skull. Not even laundry baskets were wide enough to fit it.
  • I would have had to use TONS of hydrogen to immerse the bone. I’m not a rich person and wasn’t thrilled about spending $50+ on peroxide for a skull.


My first (unsuccessful) solution: Soak the skull in a doubled trash bag

Since I couldn’t find a container large enough for the skull, I put the skull into a big trash bag, poured in some hydrogen and water, and then tied off the bag. I kind of propped everything up in a plastic drawer.

Of course the trash bag sprung a leak.  The peroxide pooled at the bottom, so only part of the skull got whitened.  You can see a line on the skull from the part which was sitting in the most hydrogen solution.  It looks terrible!

*If I had a trash can large enough to hold the skull, I would have been able to use this method: Fill the trash can with water, then put the skull in a plastic bag into the water.  The water would fill the empty space around the skull so less H202 would be needed.

cleaning a cow skull

Notice the whiter line from my first attempt at cleaning the skull.  


My solution: Mix the hydrogen peroxide with baking soda

Baking soda is a natural cleaning agent, right?  Could I mix it with hydrogen peroxide to form a paste, and then spread the paste on the bone?

I did a small test batch. The baking soda and hydrogen foamed a bit when mixed up, but still formed a paste that could be spread onto the skull. *You can buy cheap hydrogen peroxide here.

This is the paste I made from baking soda and hydrogen peroxide

This is the paste I made from baking soda and hydrogen peroxide. It was about as thick as toothpaste.

The great thing about the paste method is that you don’t have to use lots of hydrogen peroxide and it can be spread in all those weird nooks and crannies skulls have.   The only annoying thing is that you will have to do at least two rounds – one for the top of the skull and another for the bottom.

Applying the paste to the skull. It started foaming quickly, but the paste didn't fall off.

Applying the paste to the skull. It started foaming quickly, but the paste didn’t fall off.


Here you can see what it looked like afterwards. A huge difference!

whitened cow skull


Yet another method: Paint on cream hair developer

As I mentioned before, cream hair developer has emulsifiers added to thicken it.  What’s cool about this is that you can paint it directly onto bones.  There’s no need to mix it with baking soda to thicken it! After applying, cover the bones with plastic wrap.  Otherwise the cream developer will dry out too quickly.

Like with the baking soda paste, this method also won’t clean the interior of the skull.  Make sure your skull is completely clean of tissue before you try to whiten it by painting on cream developer.

whitening bones with hair developer

Pig skull with cream hair developer painted on it.


Want more tips on how to clean bones?

Have questions about antlers, horns, beaks? 

Want to know how to glue together bones?  

These are all things I talk about in my eBook.  Get it here for $4.99.  😀how to clean bones book

And here’s an infographic. Please Pin It! 🙂

How to clean bones infographic


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About the author /

Diane Vukovic is an avid traveler, outdoor enthusiast and couchsurfer. She loves finding ways to explain complex topics to her 9-year old daughter and hunting beetles with her 1-year old. Follow MomGoesCamping on Facebook and Twitter @MomGoesCamping to stay in touch!

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  1. Bethany

    With the paste method, how long did you leave it on? Did you scrub it with the toothbrush, or just apply and let it sit? After soaking or past methods, do you just rinse with water? Thanks!!

    • Diane

      I used a toothbrush to apply the paste. No scrubbing needed. I had planned on leaving the paste on at least overnight… but then it started to rain. So, it ended up being just about 5 hours or so. The rain rinsed it off! If it hadn’t rained though, I definitely would have rinsed it with water. Note that the baking soda and hydrogen peroxide solution will bubble up when you make the paste, but it still works well. I have since switched to using hair developer instead of normal hydrogen peroxide. The hair developer doesn’t bubble so works better for making a paste. (I’m going to write a post on that method soon!) *If your bone is small, it’s probably better to just soak it in hydrogen + water. That ensures the solution gets into all the nooks and crannies. Otherwise, you’ll have to apply the paste more than once, since you can really only do either the top or bottom at a time with the paste.

  2. Rachel

    What ratio of baking soda to hydrogen peroxide did you use?

    • Diane

      It is probably around half/half, but I don’t measure. I just add enough of each to make a paste which was about as thick as toothpaste. If you are using hydrogen peroxide (and not hair developer), it will bubble when you mix them. Just spread it as it bubbles. Good luck!

  3. Robsaint

    Here’s another great way to save on peroxide for large skulls;
    Put the skull in a bin bag.
    Place the bin bag inside a bin or other large container.
    Fill bin/container with water. This pushes air out of the bag making a snug fit around the skull.
    Fill remaining space inside bag with 50/50 peroxide/ water. Thus using far less peroxide and getting great results.

    Discovered this method from fellow skull collectors on Facebook groups.

    • Diane

      That’s a great trick! With the cow skull shown in the article, I tried putting it just in a bag and the bag broke (which is why there was a white line around it from where the h2o2 accumulated at the bottom of the bag). Putting it in a bin and filling it with water would have prevented the bag from breaking. Thanks! 🙂

  4. Alona V.

    Hey guys! There is no way for me to get a good amount of hydrogen peroxide in my country. In case the bones don’t have any tissue on them would soaking them for a few days in hot (but not boiling) water with laundry detergent, replacing the solution every 24 hours and occasionally brushing it with baking soda\toothpaste and tooth brush be good enough?
    I am not very interested in whitening the bones, maybe just a little bit.

    • Diane

      Most laundry detergent has bleach in it. It will clean and whiten the bones… but bleach will make the bones turn flaky after a while. Even if you can’t find hydrogen peroxide in big bottles where you live, you probably can find hair developer (that’s what I use now). Just go to a beauty supply store and get it. Use it + some water for soaking the bones. They will be clean and whiter. 🙂 For a large skull, you can get by with just 1 liter of hair developer (costs about 10-15 euros in beauty stores). To save on it but still get the skull clean everywhere (including inside all those foramina holes), I first soak the skull in water with just a bit of the hair developer. After a day or two, I dump that solution. Then I’ll apply a paste made from the rest of the hair developer and baking soda.

  5. Kaylin Brodzki

    Are these methods safe to use on bird bones? I’m a little worried about weakening or breaking the bones of this beautiful specimen I found while cleaning my patio for spring. The remains are already mostly clean, however there is a bit of tissue I still need to clean off…

    • Diane

      Yes, bird bones are super fragile. Macerating (soaking in water) is probably the best solution. Be warned that soaking will make the beak sheath crack and warp. Even many professionals don’t even bother trying to save the beak sheath because it is so fragile.

      If the beak sheath is still intact, you can let the bird bones sit in the open (or in a box with holes poked in it). Every few days, give the beak sheath a tug to pull it off the bone. The sheath then gets stored in Borax until the bones are clean. Then you glue the sheath back on.

      As for whitening the bird bones, hydrogen peroxide is fine. The only issue you might come across is the beak or certain areas of the skull coming apart, since the skulls are actually several pieces held together by connective tissue. This is often the case with young animals. I use a plastic tea strainer to catch tiny bones when dumping the H202.

  6. Name *

    Hello I Have A dog skull i’ve dryied the skull and i cleaned it but it still have some bad smell can you lead me please what to do Thank’s

    • Diane

      Sometimes bones get a weird smell when they are still wet, but it goes away when they are dry. However, if the bones are dry and still stink, then it is probably because there is still lots of grease in the bones. You’ll need to:
      -try degreasing (soaking in soapy water) again. You might see some nasty tissue you missed float up too! Yellow spots on the skull are a sign that there is grease trapped inside.
      -Consider removing the teeth (carefully – they crack easily). There could be some nerve endings or other tissue stuck under them. Reinsert the teeth while the skull is still wet or they might not fit back in.
      -Use a wire to poke into any holes in the skull. There could be tissue lurking in there – especially if the skull was boiled to clean tissue off.

      After soaking/degreasing again, do another round of hydrogen peroxide. Put it outside to thoroughly dry. You can also soak it in rubbing alcohol to force water out of the skull, but this is probably not necessary.

  7. Name *

    Hi there! Just wondering, what if you have just a turtle shell? Could you just clean with soapy water? Or is there a way to disinfect it without changing the color? Thanks!

    • Diane

      The colorful part of turtle shells is actually a sheath made out of keratin (much like fingernails and also animal horns). Unfortunately, keratin is really fragile. Don’t soak the turtle shell or the sheath will come off and warp.

      Your best bet is to let the tissue rot off of the turtle shell in an open space. Unfortunately, the sheath might still separate from the bone. If this happens, you’ll need to store the sheath in Borax until the rest of the shell/bone is clean. Then you can glue the sheath back on, possibly letting it get a bit wet so it softens and fits back on nicelly.

      If you want to whiten the underside of the turtle shell (the bone part), you could paint some hydrogen peroxide onto it. I talk more about this in my ebook –

      Hope that this helps!

  8. Dawen

    Hi, I’m mostly concerned with sanitization. I found bones on the beach which are completely stripped of flesh. Right now the color is amazing and I don’t really want to whiten them. Currently I’ve got them in water and Dawn dish soap for degreasing (I’ll see if that affects the color at all, I guess). Would that be enough to sanitize them? Or do I still need some hydrogen peroxide, and if so, what’s the minimum I could get away with?

    • Diane

      If they’ve been on the beach for a long time, the exposure to sun and salt water should be more than adequate to sanitize them. If you like the color, then don’t do anything at all 😀

  9. Laurie

    I am selling my home so I dug up my dog in order to take him with me. We buried him about 4 years ago and we live in a pretty hot/dry climate and there are only bones left with some tiny bits of fur. I don’t want to damage his bones but I want them to look nice and possibly even try to put his skeleton back together. I already put them in 2% peroxide to disinfect them. Will I also want to degrease them? They are very yellow, but I don’t mind the color at all.

    • Diane

      Yellow usually means that there is oil left in the bones. However, when an animal is buried, microbes will usually eat a lot of the oil out of the bones. That’s why buried bones usually turn out nice and clean but bones which were boiled will get gross (boiling will trap the oil in them!).

      Over time (which could be a very long time), oil left in the bones will start to go rancid and destroy the bones. And stink in the process. So, degreasing is necessary if the bones are yellow. But degreasing is also a very long, tedious, and often frustrating process (I’m working on a post about it now. The post is taking forever because degreasing takes forever!!!!).

      I would recommend this: Get some stronger hydrogen peroxide (there’s a link in the article for hair developer which is 12% hydrogen peroxide. You can also get it in some beauty shops – ideally get the “clear” kind and not “cream”). Do another round with the stronger hydrogen peroxide. It not only disinfects but whitens the bones. Then see how yellow the bones are. The yellow might just be discoloration from dirt. If the bones are still yellow, then you’ll need to soak in warm water with lots of dish soap until the oils come out.

      BTW, I’d love to see photos of the articulated bones if you succeed. I have yet to get a complete skeleton of an animal large enough to articulate. 🙂

      • Laurie

        Thank you for your reply! I will go get some hair developer and give that a shot! I will definitely send you pictures if I am successful putting his skeleton back together. I also want to paint his skull in a Día de Muertos style even if I can’t articulate his skeleton. 🙂

  10. Clair Nelson

    Hi I have just today burried a Heron skull in a damp dark woody area of my garden right way up in bewteen a layer of sawdust. The soft tissue was already very decomposed, eyes missing etc. I have cleaned off as much skin as I could. How long do you think I should leave it in the ground for? Also do you have any tips on preserving the beak/keratin?
    many thanks

    • Diane

      Updated: Beaks are really hard to preserve on birds. Even a lot of professionals don’t bother to preserve them because they are so fragile.

      To save the beak, you’ll need to keep the dead bird above ground to let the tissue rot off. Every day or so, give the beak a little tug. The sheath should come off as it loosens from the rotting. You can then store the sheath in Borax powder until the rest of the bones are clean. Afterwards, you reapply the beak sheath over the core with a bit of glue to hold it on. Unfortunately, it’s a really tricky process. 🙁 I talk about this more in my ebook –

  11. Jane

    First of all, I love how you are fully embracing and empowering your daughter’s passion! And thank you for this thorough help! This is the best resource I’ve seen so far and I’m grateful. Hoping you can help me with something specific: I am currently degreasing some “nature cleaned” seal bones found on the beach. They seemed dry but of course are super greasy and stink to high heaven!! I’m wondering if you have any recommendations (or if it’s just to have patience with this process..?) for extracting the gunk. There are a few spinal bones which are fascinating. The cord was gone but the connective tissue between the vertebrae. As they’ve been soaking (dawn and water, out in the sun, changed every 24 hours), the vertebrae are starting to look gummy where they used to connect, and some white bits are coming to the surface as well. How can I effectively degrease and get rid of this stink as quickly and efficiently as possible? Like you, my apartment living is limiting my options here. Thank you for your advice!

    • Diane

      Seal bones! That’s awesome!! I’m looking at a picture of their skeleton now. It makes sense that they are greasy since sea mammals have so much blubber on them. Ammonia is an effective degreaser and is easy enough to work with.

      I also found it beneficial to cycle between degreasing (with warm, soapy water) and hydrogen peroxide. Even though H202 doesn’t actually degrease, it does seem to help push the fat out from the center of the bones. Otherwise, the fat just kind of dissolves and sits in the bones. It also really helps to use very warm water for degreasing. A lot of people buy aquarium heaters to keep the water warm so they don’t have to keep changing it out as the water gets cold.

      I wrote more in detail about all these methods in my ebook It’s just $5 if you want to buy it 😀

      Just be prepared for a long battle. Degreasing is a pain in the butt.

      • Jane

        This is immensely helpful. Thank you for this thorough help and reassurance. Having launched headfirst into this project without fully knowing what to expect, I can’t tell you what a relief it is to have your site and thoughtful comments as resources.

        How do you know when to stop degreasing? Do the bones need to dry out in between the water and H202 or can they just switch baths?

        On the vertebrae, will the gummy/gooey/tacky surfaces stop looking that way with enough soaking, or is it a judgement call on when to call it quits?

        Thank you again so much. Really appreciate your help with this project.

        • Diane

          It will lose its yellow color and translucency when degreasing is done. Again, it can take a REALLY long time. Can you see the water getting gross and murky, maybe even with globs of fatty stuff floating to the top?

          You don’t have to let it dry out between baths. However, if you want to cycle between H202 (hydrogen peroxide) and degreasing, you should let it dry out. Bones absorb H202 much better when they are dry.

          I wonder if the tackiness is from grease or not. If there’s a lot, then it might be some tissue left over. The discs and connective tissue on vertebrae can be tough to get off. In that case, drying it out will probably help. Once it’s dry, then you can scrape it away with a scalpel. See this post:

          Also check out this thread: It’s a crocodile in question, but you can see how much tissue is stuck on the bones.

          And I’m glad to be of help. I love knowing that there are so many other “bone ladies” out there, haha! 😀

          • Jane

            Truly a life saver thank you!!
            there definitely isn’t visible tissue left- the bones were very picked clean, but maybe the connective tissue is different? I’m definitely learning a lot about anatomy here! Can’t find a great picture but in this link, the part that I’m talking about is the “body” – and on that body is a tacky spot in that solid part, in a oval shape, on both sides of the bones where they connected to other vertebrae. The spot is a creamy yellow color where the rest of the bones are white. Could that be some kind of tissue, or is that marrow or something? After the first soak there were little bits of feathery white matter coming off of those spots too.

            After the first soak (48 hours, Dawn), the water ran yellow, but with consequent soaks it was lighter and lighter and never had anything floating. The smell continued to be horrible, though a little lighter each time.

            I put them in baking soda to dry and try to transport without horrible smells… I’ll finish drying them and will see if those softer spots can be scraped at all, and will then try the H202 soak to see if anything can be further drawn out. Stay tuned!!

  12. Elizabeth M MacNaughton

    I’ve recently started collecting road killed white tail deer bones from the gravel pit where the county dumps them. They have been mostly cleaned of tissue by bugs and scavengers. I would like to clean them up to use as decorations in my tarantula’s tanks. What percentage of H2O2 to H2O do you use? I bought the 12% 40V you recommended above. Thank you for your time and expertise!

    • Diane

      The more H202 you put in, the whiter they will come out. But it also means you’ll blow through H202 quickly. I’m not too scientific about it at all. About 50/50 is a good ratio. When the bones aren’t too dirty, I’ll use even less H202. If I want them even whiter, then I’ll do another round of H202. Really, don’t obsess about ratios. 🙂

      The county has a specific place only for animal remains??? God that has to look creepy and cool!

  13. Katrina Brown

    Any suggestions on how to remove plant matter (roots / moss) from tight places? Between teeth, inside skull cavity, etc. Also, any suggestions on how to get rid of impacted mud? Thank ou!!

    • Diane

      Pipe cleaners work well for pushing dirt/plants/etc out of tight places. Usually (on skulls) the debris is stuck in the nasal cavity. That sucks because I love how the nasal cavity looks, and you can’t really push anything into it without destroying its delicate structure. So, you can soak the bone to loosen/soften the debris. Then use a hose to blast out the debris. Depending on where the debris is located, you can aim the hose from the nose or from the hole in the back of the skull.

      As for mud, soaking is the way to go. It will loosen mud and then you can use an old toothbrush to brush it off. If there’s still mud stuck, then you can just let the hydrogen peroxide do its magic. Its bubbling will push the dirt out. May take several soaks though.

  14. Name *

    Hey Diane, this helped me so much! I found a pretty clean rabbit skull recently and it’s sitting in the whitening bath right now. Unfortunately I only got cream developer, but at least the 12%-kind. I’m very excited how it’ll turn out – thanks for sharing all of your valuable experience with us!

    • Diane

      I’m glad to be of help. I have a rabbit jawbone. It’s fun to pull the teeth (incisors) out of the skull to show people how far into the skull they go! Cheers. 😀

  15. Kristie

    Wonderful information! Thank you so much! I’m curious if the burying method for step one can be used for a deer skull with antlers. Will the bugs and soil bacteria eat the antlers? I live in Seattle where we are currently entering the rainy season. Will soil wetness be a detriment to the process? Thanks again!

    • Diane

      Antlers are actually bone, so they won’t be eaten by bugs etc as horns will (horns are made of keratin like our fingernails). That’s why you can sometimes find antlers just laying around in nature. So, it’s perfectly fine to leave antlered skulls out for insects to clean. The antlers might get a bit stained if you bury them though. I talk about this in my book in case you need more detail. 😀

  16. Alice Dudoich

    Thanks so much for the book you wrote. I’ve been collecting bones from my sister’s property in Alabama for years but am just now trying to do something with them. I am working with a dog skull and got carried away with a red Sharpie decorating the skull with native American motifs. Didn’t like it and when I tried to remove it, I wound up with a breast cancer pink skull. Any ideas about getting it back to white? Thanks again!!

    • Diane

      Hmmm… that’s a tough one. I guess I’d try using hydrogen peroxide to remove it (maybe that’s what you already tried). If that doesn’t work, then I’d work with the pink color. Think of it as a challenge to make something cool with a pink skull! 😀 As a last resort, you could always paint over it.

  17. Melissa Myers

    How did you fix the cow skull that was stinking? If it’s stinking does that mean it still has fat in it? I found a seal flipper (I think) at the coast and I’ve soaked it and soaked it in dawn and water and it still smells horrible. Could I try to use baking soda to deal with the smell?

    • Diane

      The cow skull only stunk because of the rotting plants/debris inside of it. My pig skull, however, stunk because of all the grease in it. Seals (as well as bears and possums) are really greasy too.

      Degreasing is a serious pain in the ass. It literally took over a month of soaking the skull before the fat came completely out. There are things you can do to make it go faster, like keeping the water warm with an aquarium heater or cycling between degreasing and hydrogen peroxide. Or, instead of soaking in dish soap, you could try soaking in ammonia or acetone — but that must be done outside because of the fumes. Also, the acetone has to be completely evaporated from the bones before you try hydrogen peroxide again because the two are explosive together! 😮

      The best advice I can give to you is to be patient with degreasing. Baking soda might help with some of the smell temporarily but, because the grease is inside the bone, it will start to rot and stink.

      • Jane

        Hi! Me again from July seal bones! I have been soaking the vertebrae and rib bones for coming up on 12 weeks now. I was changing the water weekly but since it’s such a gross and stinky project have been letting them soak for 2-3 weeks between changes now. The water has gotten progressively lighter but they’re still a bit smelly. It went from a dark yellow brown color to more of a pale brown, mostly clear. The smell is more tolerable now (no more gagging, at least!) but definitely still feel like I’m miles away from a point where I will feel comfortable bringing these inside the house. Will try hydrogen peroxide this week for the next soaking, and hope that takes it up a notch. How do you know when you’re finally done with the soaking and can begin the actual whitening with the peroxide and eventually drying and displaying? Thank you again for all your help and support!

        With the flipper I’d imagine it will need a similarly long soak, depending on the size of the bones.

        • Diane

          You’ll know you are done when the bone doesn’t have a translucent look to it anymore. Definitely try doing a hydrogen peroxide bath. H202 doesn’t cut through grease, but it does help you see where there is still fat lurking and helps push some of the fat out from deep inside. I’ve never had to deal with a bone that greasy (it seems like seals are exceptional when it comes to grease) but I have heard of people soaking bear skulls (also greasy) for months before getting them done. 🙁

          *The bones will stink less when they are completely dry. But there may still be fat inside the bones that can rot and over time destroy the bones. I know this is frustrating. I feel you!!!!

          Btw, I’d love to see photos. You can send them to if you wish. 😀

  18. Name *

    I’m trying to get some chicken bones cleaned and whitened to use for decorations on a Halloween Witch doctor costume.

    I managed to get hydrogen peroxide at 6% here in Malaysia and was wondering if its ok to use on bones i boiled and cleaned using soap water. 🙂

    • Diane

      It depends on how long you want the decorations to last. If you boiled the bones, then there might be lot of fat trapped inside of them (if the bones are clear looking or shiny, then there’s fat in them). Over time, the fat might start rotting and the bones will stink. That could be a year from now, or 10 years… Since these are just chicken bones, I guess it won’t be that big of a deal to throw them away later.

      Yes, you can use the 6% hydrogen peroxide on the bones. They should get nice and white (at least whiter) and make for some cool decorations. 😀

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