Birch oil and birch tar
Instructions on making birch oil and birch tar
On this page I will explain how to make birch oil and birch tar. You will find out what this is, where it can be found and where it can be used for. Also the proces of making the oil and tar will be explained. You’ll get tips and tricks on speeding up the proces and learn what to do and not to do in the proces.
As a survivalist, this is a great skill to be able to use glue when you want to make fish-hooks or arrows. As a bushcrafter, maintaining your material with birch oil is very important to make a long, independent, stay in the forest possible aswell as the previously mentioned advantages for the survivalist. The use of birch glue comes in handy when traps, pothooks and kuksa’s have to be made or clothes or bags have to be fixed (waterproof!). The possibility’s of birch-oil and tar are endless.
This is an awesome skill to be more self-reliable in your outdoor adventures!
Birch tar has been used in northern Europe as a superior glue as far back as 80,000 years. It was used among other things to glue feathers at the end of arrows, fix blades of axes into their handles and to glue broken pots together. In Finland there have also been traces found of tar, used as chewing-gum. I think although, this might be a misconception as it also could have been that people chewed on tar to heat it before using it as glue.
Otzi the iceman, a mummificated man who lived around 3,300 BCE, found in the Ötztal Alps back in 1991 had arrows with him which were hafted with birch tar.
Birchtar also have been used as a topical medication which has been used to treat wounds, burns, skin ulcers and suppurations but this use was later associated with a higher risk of skin cancer, hematologic or other malignancy.
As tar is a product which is produced when thickening birch oil, it can can be assumed that birch oil has been used since people discovered birch tar.
In the 17th and 18th century, ‘Russia-leather‘ was a major export good from Russia because of it’s water-resistant properties. After the leather was tanned, the people oiled the leather to prevent it from rotting and mildew.
The oil impregnation was also used as deterred for insect attacks as it masks the body odour.
Birch tar oil can also be used as an effective repellent of gastropods in your garden. Normally the repelling effect lasts about two weeks but mixed with petroleum jelly, the effect will lasts for several months when applied to a fence around the garden.
Birch tar oil is industrial mostly used in perfumery as a base-note to impart leather, tar, smoky, and wintergreen notes.
Wide pot or can with birch-bark vertically collected inside.
Hole in bottom wide pot/can.
Bowl or can to collect and cool the extracted birch oil. Dug in the ground to support an oxygen-free environment.
Sealed seams with sand or ash.
Fire build on top of the birch-bark pot/can.
There are two different ways of making birch oil and tar.
The most natural way is by using pots made out of clay. The other way is to use metal cans instead.
Make a low but wide pot out of clay with an open top, in the bottom slightly sloping towards the center. Pinch a small (about 0,4 inch / 1 cm wide) hole in the center of the pot. This pot will be used to collect the birch bark in.
Now make a bowl to collect the oil in. the bowl needs to be about 1/3th of the size of the pot as this is the amount of oil you will approximately extract. At this point the pot and the bowl do not yet need to fit exact onto each other but working to perfection can help you later. In the end the bowl will be placed underneath the pot.
Now bake the pot and bowl underground to let the clay cure.
Stay in the area as you need more clay later-on in the proces.
Using metal cans
Get one can with a wide diameter with a tight-fitting lid and a smaller one in diameter without a lid. The tight-fitting lid on the bigger can is needed because the collected birch-bark will catch fire when heated in an oxygen-rich environment. Pinch a small (about 0,4 inch / 1 cm wide) hole in the center of the the bottom of the wide can.
The raw material for making birch oil and tar is birch-bark. Small wispy papery bits can be peeled off of living birch-trees as long you don’t peel until the inner bark in which the sap-flow of the tree is present. Big patches can be collected from dead birch-trees. the patches must be dry before starting the extraction proces so no moisture will contaminate the oil and tar.
Different species of birch trees can be used for this purpose.
When collecting birch-bark, be sure not to harm the natural environment more as needed.
Do not collect all of the bark at one place but search for different trees to collect a little amount from.
Keep this in mind when you’re collecting bark. Collect a little amount of bark from different trees regardless whether the tree is dead or alive.
Place your collected birch bark vertically into the wide diameter clay-pot or metal can with the pinch-hole in the bottom. When the birch-patches stick over the edge, cut it is a little shorter as the height of your the pot/can. Vertically press all the pieces of bark together in the pot/can until there is no room for more.
Be sure you don’t cover up the hole you punched in the bottom!
In case of a clay-pot; close the top of the pot with new clay. Make sure it needs to be almost completely airtight. To prevent the pot to explode because of expanding gasses you can pinch a very small hole in the middle of the top to release the pressure.
In case of a metal can; close the lid on the can firmly. To prevent the can to explode because of expanding gasses you can pinch a very small hole in the middle of the lid to release the pressure.
Now dig a hole in the ground. Dig it as deep as the collecting bowl or small diameter can it’s height. The bowl or can has to sit with it’s rim at ground level. Be careful not to get any dirt inside to avoid contamination. Use soil to create a light seal around where the two cans come together or when using clay, add an extra ring of clay to the top of your bowl to connect with the pot on top. This will tighten the connection to the pot which comes on top. Not so tight to seal in the gasses, but enough to keep the two cans in place.
Place your pot/can filled with birch-bark (with the wide diameter), with the pinched hole on top of the smaller bowl/can. Seal eventual air-gaps between the two cans carefully with sand, ash or any other air-tight and flame resistant material. Seal it enough to make sure the inside of the cans cannot catch fire but gasses can still escape. A too tight seal may cause the expanding gasses to blow the top off your pot or can and can be dangerous. The wider pot or can must stand stable before continuing to build a fire on top.
Start a fire over and around the wide pot/can where the birch bark is in and keep it burning for >4hrs (explained under Setup).
The fire does not have to be a big but should surround the wide pot/can well on all sides.
A good fire technique for this fire is the Up-side-down fire /Pyramid fire technique.
The birch bark oil will sweat out of the bark and drip towards the bottom of the birch bark can. From there it will leak through the hole into the birch-oil bowl/can which is in in a cooler and oxygen-free place under ground and therefore doesn’t catch fire.
After burning for >4hrs, allow the fire to burn down. When it has cooled down, carefully scrape away the ashes and soil from around the two pots/cans, being mindful not to allow dirt or ash to fall into your small bowl/can (filled with oil).
You have now extracted the birch oil from the birch bark!
The deep black oil has a very strong and distinctive smell. It can be used to treat your knife to prevent the metal from rusting, treat leather and wood so it will never mildew or rot, and even to make material waterproof or resistant.
It is highly flammable so it can also be used to light a fire.
Vishnevsky liniment is a product which has been used to treat wounds, burns, skin ulcers and suppurations and contains birch oil. Later came to light that a prolonged application of this product could be associated with higher risk of skin cancer, haematologic or other malignancy. I couldn’t find which of the separate ingredients of this product was causing the higher risk on cancer.
For this reason I wouldn’t use this product directly on the skin like as face paint, a bug repellent or for medicinal uses (treating wounds, burns, skin ulcers and suppurations).
To make birch tar or pitch, boil down the oil very slowly. Work in a well ventilated environment as I can imagine that the strong vapours are very bad for your health. Wearing a gas-mask might not be a bad idea.
When boiling down the oil into tar, make sure there is no open flame as the fumes and oil are very flammable. For this reason it is best heated outdoors on a hot charcoal bed. When the oil is thickening, regularly cool your can or bowl to see if the oil solidifies into tar. Make sure you do not overdo it as the substance goes from oil to tar to useless carbon in a short amount of time.
When the tar will firm to your desired consistency remove it from the heat and allow it to cool. The birch tar can now be stored and used as glue and other purposes.
Birch tar becomes very hard in cold state and has a deep black colour.
The birch tar is completely water proof and can be used to seal seams on boots, moccasins and your backpack. It can be used to glue feathers to an arrow or fill gaps when hafting arrow and dart points. Also a loose axe-head can be fixed steady onto its shaft.
|Birch tar/pitch is:||
|In an absolute solid state at||
|In a thermal plastic state at||
|In a softer state and can be moulded in your hands at||
|In a soft sticky putty state at||
|In a boiling state at about||