Birch bark tar (sometimes referred to as birch barkpitch) is a substance that is synthesized bydry distillation ofbirch tree bark.

Birch bark tar is mainly composed oftriterpenoid compounds of thelupane andoleanane family, which can be used as biomarkers to identify birch bark tar in the archaeological record. The most characteristic molecules arebetulin andlupeol, which are also present in birch bark.^[1][2] Some of these molecules degrade into other lupane and oleanane skeleton triperpenes. The most commonly found additional molecules are lupenone, betulone, lupa-2,20(29)-dien-28-ol, lupa-2,20(29)-diene and allobetulin.^[3][4][5]

Birch bark tar use as anadhesive began in the MiddlePaleolithic.Neanderthals produced tar through dry distillation ofbirch bark as early as 200,000 years ago.^[6] A 2019 study demonstrated that birch bark tar production can be a simpler, more discoverable process by directly burning birch bark under overhanging stone surfaces in open-air conditions.^[7] However, atKönigsaue (Germany), Neanderthals did not make tar with this method but rather employed a technically more demanding underground production method.^[8] A find from the Dutch North Sea^[9] and two tools from the Italian site Campitello show that Neanderthals used birch bark tar as a backing on small 'domestic' stone tools.

Birch bark tar also has been used as adisinfectant, inleather dressing, and in medicine.^{[citation needed]}

A piece of 5,000-year-oldchewing gum made from birch bark tar, and still bearing tooth imprints, was found inKierikki, Finland.^[10] Genetic material left in the gum enabled novel research to identify population movements, types of food consumed, and types of oral bacteria found on their teeth.^[11]

A different chewing gum sample, dated to 5,700 years old, was found in southernDenmark. A completehuman genome and oralmicrobiome was sequenced from chewed birch bark tar. Researchers identified that the individual who chewed the gum was a female who was closely related genetically tohunter-gatherers from mainland Europe.^[12]

Fletching onarrows were fastened with birch bark tar, andrawhidelashing and birch bark tar were used to fixaxe blades in the Mesolithic period.

Birch bark tar was more frequently discovered in archaeological contexts dating from theNeolithic to theIron Age. For example, birch bark tar was identified to serve as an adhesive to repair^{[13][14][15][16]} and decorate/paint ceramic vessels,^[17] as a sealing/waterproofing agent.^[18][19] A well-known example of birch bark tarhafting during the copper age isÖtzi’s hafted arrow points and copper axe.^[20] Multiple discoveries show that birch bark tar was also used to assemble metal artefacts, such as pendants and other ornaments, on both a functional and decorative level.^[21][22] During theRoman Era, birch bark tar is mostly replaced by wood tar,^[23][24] but birch bark tar is still used, for example, to decorate hinges and other bone objects.^[25]

Russia leather is a water-resistant leather,oiled with birch bark oil after tanning. This leather was a majorexport good from seventeenth- and eighteenth-century Russia, as the availability of birch bark oil limited its geographical production.^[26] The oil impregnation also deterred insect attack and gave a distinctive and pleasant aroma that was seen as a mark of quality in leather.

Birch bark tar is also one of the components ofVishnevsky liniment.^[27]

Birch bark taroil is an effectiverepellent ofgastropods.^[28] The repellent effect lasts about two weeks.^[28] The repellent effect of birch bark tar oil mixed withpetroleum jelly and applied to a fence can last up to several months.^[28]

Birch bark tar oil has strong antiseptic properties,^[29] owing to a large amount of phenol derivatives and terpenoid derivatives.

Birch bark tar oil was used in the eighteenth century alongsidecivet andcastoreum and many other aromatic substances to scent the fine Spanish leatherPeau d'Espagne. At the turn of the twentieth century, birch bark tar had become a specialty fragrance material inperfumery as a base note to impart a leathery, smoky note in fragrances, especially from the leather and tobacco genre, and to a lesser extent inChypres, especiallyCuir de Russie perfumes and fragrance bases, typically together with castoreum and isobutyl quinoline. It is used as an ingredient in some soaps, i.e. the scent ofImperial Leather soap, though other tars (i.e. from pine, coal) with an equallyphenolic and smoky odour are more commonly used in soaps as a medicating agent.

• Non-video demonstration
• Treating Leather With Birch Tar

• Adhesives
• Non-timber forest products

• Articles with short description
• Short description is different from Wikidata
• All articles with unsourced statements
• Articles with unsourced statements from October 2012