Burra's Bone Sauce Experiment

I've been planning to make bone sauce for a while. There's no way I'm going to be able to afford to fence all the land, and we've been warned that if we attempt to plant fruit trees without a good fence to keep the wild boar out, they will just dig them up again. We also have trouble with hares, and the donkeys and geese like to nibble at bark, too. So Sepp Holzer's bone sauce recipe seemed just the thing.

Here's a link to Paul's video, which was invaluable!

This morning we finally got round to it.

We had already loosened the soil in an area ready for digging out and turning into a hugelkulture bed, so I figured that was a good place as there was no vegetation there to catch fire and the loose soil would be easier to cover the cauldron with after the fire had been put out. I'd been collecting bones for a while, mostly from our own chickens as the surplus males got turned into pie, but also a few pork bones. I'm not sure if the chicken bones are quite the right thing as I heard that it was the fat in the bones which produces the bone sauce, and I don't think there's much fat in them. But there's only one to find out...

Here's my equipment - a bucket of bones, a cauldron, a stainless steel mixing bowl, some chicken wire, and a wooden mallet.



I also had a digging spade, a hose-pipe and a full tank of water.

I'd been storing the bones in a lidded plastic bucket and they'd gone a bit slimy, especially the ones on the bottom, which are the ones that ended up on top by the time I tipped them into the cauldron.



I bashed them down with the mallet until they were below the 'neck' of the cauldron, then folded the chicken wire and pushed that into place on top, tucked under the shoulder in the hope that it will stay in place when I turn the whole thing upside-down and not let the bones fall out.



Then, get a suitable volunteer to dig a hole for the bowl.



Put the bowl in place and fill in the worst of the gaps. The bowl should be in contact with damp soil to keep it relatively cool. Traditionally two matching cast iron pots would be used, but the only cast iron 'pots' I could find were cauldrons, and pricey, so I improvised with a stainless steel mixing bowl I'd found for a euro which just happened to be a good 'fit' for the neck of the cauldron.



We damped the soil down well - I really don't want another forest fire!!
The bowl had about a cup of water in.



Carefully invert the cauldron over the bowl, checking that the wire mesh, and the bones, stay in place.



Yup - that looks roughly level. Ish...



The joint between the bowl and the cauldron should be sealed with clay. We don't have clay, so we chose the squishiest, most clayey soil we could find and used that. Great fun!





Then we filled in all the gaps with wet soil.



Dunno what it looks like. An alien space helmet? Some kind of land mine?



Time to build the fire. Teenagers know better than moms how to do this, apparently, so I wasn't allowed to help.

We had some old ply-wood which had fallen apart and was destined for the hugel-bed, but it made good kindling, too.



The legs of the cauldron were handy for keeping the wood in place!





A few pine cones, a couple of sticks...



...some bits of newspaper - and she's away!



It needs to burn, gently, for two hours.



Which should give us plenty of time to cook a few potatoes.



I feel sure there should be a better way to cook them than wrapping them in alumimium foil. All suggestions welcome...

I also suspect that next time around, there will be some kind of barbeque grill balanced on top of the cauldron legs, and the wood will be cut a bit shorter.



Now just sit back and wait for an hour, replacing the sticks often enough to keep the whole thing ticking over.



Are they done yet?





Om nom nom. Have to keep your strength up somehow while you're watching the fire.



After the two hours are up, and the potatoes eaten, it's time to cover the cauldron with earth. I really don't know if this is for safety or for insulation, but figured it was best to just do it and worry about why another time.



I thought that was enough photos, so I took over, and that sneaky teenager snatched a snap of me. Alright, just this once. But only because I had my best t-shirt on!



We're going to leave it there til morning, so watch this space!

Great step-by-step photos. Looking forward to the results.

Indeed! I want to see the results, good or bad. If you can't get clay, you can get small quantities from the cheap cat litter. I'm seeing home metal casters on YouTube grinding cheap cat litter to come up with clay. Search: "making your own green sand".

Sorry guys - I'm a day late writing this up!

Yesterday morning, we dug the cauldron out (we meaning my son, with me supervising ), being careful to remove as much soil as possible to stop it falling into the bowl as we lifted it away.



I tried to find a broom to sweep the last traces of loose soil away, but for some reason I couldn't find one anywhere. So we used a donkey brush - *everyone* has one of those handy!



Then the moment of truth...

Did the bones stay in place?

And is there any sauce?



Yes!



It's much runnier than I expected. Maybe it's because the bones were slimier, or possibly I didn't keep them hot enough for long enough.



The bones didn't seem as charred as I expected. Maybe I should have kept the fire hotter.



My other half was feeling left out, so I let him prepare the sauce for daubing onto the trees. We added a litre of el-cheapo cooking oil...



... and stirred it in. Mmmm - gloopy...



All it needs is eye of newt and toe of frog...



We poured most of the gloop into a used plastic bottle.



I was expecting a really disgusting, totally overpowering smell, but it didn't seem quite as bad as I thought it was going to be. Kind of like dead burned things. As you'd expect really. But the following morning it somehow seemed far worse and invoked all kinds of morbid memories.

I wanted to experiment with it as soon as possible, partly because of what was going on in this photo, which was taken a month ago, and was one of the reasons I wanted to make some bone sauce in the first place!



That tree got a good coating of oil! I wasn't really sure how much to put on, so I painted it pretty well everywhere I could reach with the paint-brush that didn't involve getting any on the leaves. I'm not sure if this was the best idea in our hot, sunny climate in case the oil overheats in the sun and damages the tree. I'll find out soon enough I guess. This tree had its first figs last year and the geese took great delight in jumping up and down trying to snatch mouthfuls of fig before they were quite ripe enough to be worth picking. I'm hoping the smell of the bone sauce will put them off enough so that I get a chance to sample them myself this year!



I also got attacked by our breeding cockerel as I was doing this - he doesn't like me wearing different t-shirts. I flicked some bone sauce at him off the end of the paint-brush and he stopped in his tracks for moment, then launched into a second attack, so I flicked him again. This time some must have landed on his beak as he froze, looked mortified, and took himself off somewhere else pronto. The effect didn't last, unfortunately, as he had another go at me this morning. I usually eat them when they do that, but I need this one to produce my strain of green-egg layers, so I'm going to go armed with more bone-sauce tomorrow and see if I can re-educate him.

This is one of our cherry trees - the ducks like jumping up and down pinching the cherries when they are ripe, so this tree got a good coating, too!



I ended up painting half of the young trees in the poultry area, just in case there were any unexpected side-effects.

This morning I decided to try another experiment. It's not really the right time of year to plant trees in Portugal - the ground is starting to dry out and the sun is getting too strong and the poor tree is going to have a hard time finding its feet and putting new roots down fast enough to cope. But I didn't feel like waiting til autumn. So I planted a plum tree in the main donkey paddock, which is empty at the moment as the donkeys are on duty grass-clearing in the olive grove. The soil there in the paddock is already very dry, and badly compacted, so I really don't know if I can keep the poor tree alive over the summer, but at least I'll get some idea of how the donkeys react to the bone sauce. I also planted a quince tree on the land below the farm, which was once surrounded by a stone wall but now is basically just open countryside and regularly raided by wild boar. I would really, really like to get a load of trees planted there as the land was totally abandoned for about twenty years, not ploughed up and destroyed like the land on the main bit of the farm, and the soil there is much softer, moister, and less devoid of nutrients and organic matter. I'm hopeful that one will survive. But between the two we should start to get some idea of whether or not the bone sauce works.

If I can find more suitable trees, I'm going to plant a load more down on the lower bit of land, and also some on the new bit we bought in the forest, and possible in the olive grove. If it's possible to establish fruit and nut trees on land that isn't adequately fenced against the wild boar, it will be a major achievement!

I'll let you all know how it goes.

I would agree, those bones look like they could have been cooked another hour or two. If you bury the bones in with your plants, it may chase off ground animals too.

Two hours was the recommended time - I think I'll try to keep the fire burning a bit more fiercely next time. I was fretting about warnings of explosions if it got too hot. I'll start collecting more bones for a second attempt.

I like the idea of burying the bones to keep ground critters away. Maybe a few around each tree to discourage the boar from digging them up would be a sensible precaution.

Boar? You have wild boar? That's like free pork! Buy a big gun. Problem --> Solution!

It's tempting. It would involve getting a hunting license, and sitting exams in Portuguese. Some of the locals set huge snares to catch them with, but they aren't legal and the local huntsmen would seriously disapprove if they caught us doing it.

I think for now I'm going to concentrate on getting those trees planted - when I'm old and decrepit I want to be able to survive out of my forest garden even when I'm not able to shoot wild boar and haul the carcass home.

wasnt the bottom bowl sapose to have oil in it?

The bottom bowl starts off with a bit of water. The the 'bone oil' drips down into it while the fire is burning. Then more oil is added later to dilute it.

Check out Paul's video - Sepp himself was there to supervise that, and his results were declared to be 'Perfect!'

Burra, I was thinking about this and I wonder it's only an effective deterrent for vegetarians?
All the pigs I've met would go "smells like a dirty bbq grill, let me at it!"

Well the only way to find out is to plant a whole load more trees down on the open bit of land and wait to see if the wild boar dig them up again.

I've been trying to think of a way to describe the effect the smell of the bone sauce has on me. The first time you smell it, when you're expecting it to be the worst smell on earth, it really doesn't seem all that bad. But it has a way of working into your sub-conscious. The second day, I started imagining old skeletons being dug up out of graveyards, and stumbling upon burned corpses, and those images would pop back into my mind every time I sniffed the stuff. By the third and fourth days, I'd find myself deliberately avoiding walking too close to trees that I'd treated as I didn't want to start visualising horror movies again. And I suspect that's how it works - it's triggering deeply buried avoidance behaviours on a subconscious level. It wasn't bad enough to stop me picking cherries and stuffing my face with them, but I was careful not to touch any treated bark, and I kept my face well away from it too. It's definitely a smell of 'death' rather than 'meat'.

This time last year all the young ducks were busy jumping up and down raiding my cherries, but this year they are all broody, and the boys are hovering around them like expectant dads, so I can't even say for sure if it's working against duck-raids.

I'm busy collecting more bones to try another batch. I want to keep the fire going a bit more strongly this time to produce that thick, tar-like bone sauce that Sepp made. I really don't know for sure if my stuff is the same but runnier, or a totally inadequate batch that wasn't made properly.

Did you plant trees without it in the same area to compare?

I plan on doing this in the fall for a hundred fruit trees I grafted. They will be young and easy pickings for the local deer, that is unless the bone sauce works.

Jordan Lowery wrote:Did you plant trees without it in the same area to compare?

No - for now I just bought two potted trees and planted one in the donkey paddock, which I will be very surprised to see live at all, and one in the 'wild boar' zone, which I think *might* live. Next time I go into town I'm going to see if I can find any more affordable trees, but even then I'm not sure I could bring myself to not at least attempt to protect them with something.

Maybe in the autumn when the trees are so much cheaper, the soil moister, and weather are a bit less harsh, I'll try something a bit more scientific.

Thank you. Very helpful.

I had been stopped by the false belief that we had to have 2 matching cast iron dutch ovens, with a grill to fit.

How close do you have to be to the bone sauce before you smell it?

I am thinking of putting it on the fence between me and my neighbors to keep their rabbits from crossing the fence and eating our garden. But I do not want to alienate them.

Thanks.

Pamela Melcher

You have to be pretty close to smell it. In fact, I made myself stick my head pretty close to one of the treated trees this morning, and I really don't think people would notice it after the first day or two. I'm pretty sure I heard (or read?) that Sepp has watched wild deer and they will approach the tree ok, but when they put their mouths on the bark they will recoil in horror and never approach it again.

Hopefully, tomorrow I will put the donkeys back in their paddock and I might be able to take photos of their reaction. Of course, that's assuming that they notice the new tree and decide to investigate while I have the camera handy. Knowing my luck they'll ignore it till my back's turned.

As far as painting the fence between you and your neighbour's property, I think I'd choose a day I knew they were going out and paint it as soon as they'd gone, not attracting any attention to it. Just don't let them catch you going up to it and sniffing it to check how bad it is else they might start investigating. I'll bet they never even notice!

I found someone's blog with a page about home-made bone sauce - he'd used a big tin bought from a thrift store, made a platform half way up it with chicken wire, put the bones on top of the wire, put the lid on and then buried the whole thing in the ground with a load of rocks covering the lid. Then he built a fire over the rocks and let it burn for eight hours. It looked like it worked! Of course, I'm still not 100% certain that my own bone-sauce is quite the real deal as it came out so runny, so next time I'm going to use drier bones and cook them a bit more fiercely to try to get the same dark, thick gloop that Sepp made. If I do, then I'll be able to compare the two sorts and see if they smell the same.

Thanks, Burra,

I think that is this situation where the whole thing could explode, and factors like how dry the bones are, and how hot the fire is, play a big role in whether or not the experiment is a success, I will watch with great interest while others experiment with this - especially watching for clues about the wetness of the bones and hotness of the fire - and precisely what we need to do to prevent the thing from exploding.

I will put up the chicken wire to keep out the rabbits as soon as I can and follow this from the sidelines for now.

Thanks for keeping me in mind.

It was nice to see the pictures of you and your family and your place, so this virtual community can become a little more like the old-fashiined communities where folks saw each other face to face and lived nearby.

I hope the critters stay away from your plants!!!

Abundance for All!
Pamela

The bone sauce is an oil. Oil, when heated to 400 to 500 F will auto ignite in the presence of Oxygen. If it stays sealed, it will probably slowly consume all the oxygen in the chamber in the early stages of the process. If you broke the seal before it cooled down, it could oxidize the high temperature oil in a catastrophic manner. Beyond that, I don't see any evidence that it actually qualifies as an explosive.

In Sepp's original description of how it was made when he was a child, he said that the 'bone man' would keep a stick handy for rapping them on the knuckles to dissude them from piling too much wood on the fire as it might explode if it got too hot. I guess it's possible that too much heat might just cause the gases inside the sealed pots to expand enough that they might finally blow the top pot off, sending burning bones flying all over the place, including over the audience.

In fact, that *might* be a pretty good reason to always use cast iron for the top pot - the weight might help keep it in place. The guy that experimented with the tin used rocks on top. I assumed that was to stop the tin burning through by not letting the flames have direct contact, but the weight might have been important, too.

Thanks, Yone' and Burra,

Now it sounds manageable, although obviously one must exercise great caution.

I will be on the lookout for cast iron dutch ovens of the same size that are very inexpensive, plus a grill that fits. It seems one would want to use them only for this. Cleaning the smell out might be impossible. What was your experience with cleaning out the containers you used for this, Burra?

Plus I will be closely following others' experiments and results.

What a good group of people are on this forum. Toward a global village

I really appreciate it.

Blessings of Abundance,
Pamela

Pamela Melcher wrote:What was your experience with cleaning out the containers you used for this, Burra?

To be honest, I didn't even attempt it. The cauldron was bought specifically for making bone sauce, and though my other half did express concerns that maybe it would be of better use for cooking up chicken food I did manage to persuade him that there were already perfectly acceptable pans for doing that. At the moment it's holding the 'used' bones, but I'm going to move them out and start collecting the next batch of bones in it.

The bowl I used to catch the oil just lives in the shed next to the container of bone sauce, complete with a paint brush and the funnel, with bits of oil still smeared around it. I really don't think I could face using either of them for cooking human-food!

Thanks, Burra.

As I thought was probably true, I am looking for pots that I will use for the bone sauce exclusively. I know a very good second hand store in a rural community where they often have cast iron cookware.

Also, I imagine that larger bones have more fat in them to make the sauce. When I look at bones, it appears that the fat is in the center of the bone, not in the super hard part around the outside that holds up the critter.

The bones in the video were larger.

Often in the US there are stores that almost give away the bones, as not many people use them.

Good luck collecting the perfect bones!

Abundance for All!

Pamela Melcher

seems like some of you entrepeneurs out there should be able to find a way to mass produce and sell the stuff?

I haven't found mention of whether the bones need to be raw or not. Does anyone know?

Brenda Groth wrote:seems like some of you entrepeneurs out there should be able to find a way to mass produce and sell the stuff?

This is a wonderful idea, which I really wish I could do, and would be willing to make happen... But I just don't know how to acquire the capital for it...

I haven't found mention of whether the bones need to be raw or not. Does anyone know?

I don't see why it would really matter. Unless the bones were used for stock, in which case most of the stuff that'll turn nasty has probably been cooked out.

It seems to me that the bones would need to be raw. But ask someone who really knows what they are doing with this.

It is not hard to get bones for free from places that cut up meat.

Or put a request on Craig's list for hunters, etc.

It is my impression that the fat is a huge part of what makes this work. Cooked bones lose fat.

Good luck.

Off topic - wow catnip flowers taste good!

Love, Pamela Melcher

I made and applied the bone sauce over 2 years ago. I was skeptical at first, but it seems to be working.

We bougt the bones at the store. I ligtly cooked them, then threw the bones to the chickens so they could pick the meat off. After they were cleaned I smashed them up and made sauce and applied it.

Since then, no attacks by deer. Yea!

OK, I'm afraid I have to report the first failure. My bone sauce didn't stop the donkeys from eating a baby plum tree. The ones I planted out in the hare and wild boar area are still fine, but donkeys seem to be different.

Now I have to figure out if it was anything to do with the way I made it. Maybe I should have used raw bones, or maybe if the fire had been kept hotter.

Burra Maluca wrote:OK, I'm afraid I have to report the first failure. My bone sauce didn't stop the donkeys from eating a baby plum tree. The ones I planted out in the hare and wild boar area are still fine, but donkeys seem to be different.

Now I have to figure out if it was anything to do with the way I made it. Maybe I should have used raw bones, or maybe if the fire had been kept hotter.

If I had those results, I would probably switch over to donkey bones for my next batch!

Eric Thompson wrote:

If I had those results, I would probably switch over to donkey bones for my next batch!

But then how would I test the next batch?

Donkeys and horses are notoriously bad for chewing the bark off trees, but I figured it was worth an experiment. It would have been brilliant to have been able to report that you could plant out loads of baby fruit trees in horse paddocks and not get them eaten, but it's better if only one of us has to find out the hard way. When I get another load of bones I'll have another go and try again. Maybe with a cabbage plant rather than a tree I've had to pay hard cash for though!

The trees in the wild-boar and hare area are still untouched. I can't really declare it to be a success against those animals until the trees have been a year or two without getting damaged. I'll keep updating as things happen.

This is my first visit to the bone sauce threads. I've thoroughly enjoyed reading through this trial; thanks, Burra!

Does one need to re-apply the bone sauce on a periodic basis? (I'm thinking about your wild boar experiment & wondering how fresh the scent needs to be?)

Thanks!
Julie

Sepp claimed that the effect lasts 'forever'. Even allowing for bit of exaggeration, that would mean at least several years. I've a feeling that I'm going to dab a bit on my most vulnerable trees every year for a while though, just to be certain!

Hi Burra. Have enjoyed reading about you, your donkeys and your attempts to make bone sauce. Seems like there could be a book there. Here are some thoughts on all this from an old Montana guy. If you need to keep deer or donkeys or such out of your orchard here in Montana, you go to a hunting supply store and purchase male mountain lion urine. Deer, elk, cows, horses won't go near an apple, pear, cherry or plum tree that has that cat stuff sprinkled liberally at its base. Reapply after it rains. Birds attacking your fruit after the fruit has formed? Take a four foot chunk of thick rope and drape/coil it in your trees but you must move the rope three or four times a day---this works pretty well but is not perfect as some robins seem to be either fearless or Darwinian stupid. Don't know how either of these would work where you live but it is worth a try as neither is labor or time consumptive.

Hello All,

I was there in Montana when Sepp was making the bone sauce. We let the fire go for 6 hours or so. We also used a combination of raw and cooked bones. I believe I remember him saying that raw bones are better. I can refer back to my notes and post in this forum again.


Happy to answer more questions as well

Cheers!

This looks interesting.
We've got a new homestead with some deer bones around. Have an orchard of mostly pecan trees and wanting to grow lots of fruits. The big problem I hear is with squirrels, crows, ducks going after pecans. Will need lots of bones for all the trees. May experiment with before fall gets here and find a cauldron to cook them in.

I do actually have an important update to this thread.

Young cherry trees, bone sauce, and seriously hot summers do NOT mix!

ALL my young, established cherries trees that I treated suffered bark damage and most don't look like they made it through the winter. All other types of tree seem fine. I don't think it would be a problem in areas with less brutal summers, but there seems to be something about cherry bark that means that it reacts with the oil when the sun gets too strong. I don't know if it's only young trees that are effected as I don't have any mature ones. Maybe if we mixed the 'neat' bone sauce as it came out of the pot with white paint instead of oil, that might have been OK.

All the other trees are fine, it's just the cherry trees.

We have hot droughty summers as well into the 100s. Will keep that in mind, although most of my pecan trees are mature.

Burra Maluca wrote:The ones I planted out in the hare and wild boar area are still fine, but donkeys seem to be different.

Burra, it has been about two and a half years since the start of your experiment and I was wondering how the trees (aside from the cherries) are holding up to the rabbits and boar. If some of the trees were treated with bone sauce and some were not, I would be interested to know if you saw a difference in damage occurring to the two groups.

Burra Maluca wrote:I do actually have an important update to this thread.

Young cherry trees, bone sauce, and seriously hot summers do NOT mix!

All the other trees are fine, it's just the cherry trees.

Cherry trees have a specificity in their bark: they have small little holes (you can see them) going from inside the stem to the outside.
I can't remember how these little holes are called in english, but the tree uses them to "breath" threw the stem, that's probably why your product harmed them.

But, as written above: Burra, it's been a while since you started your experiment - could you update us on the results?