Birch Tar

What it is

Birch tar is made by heating birch bark or wood with little or no oxygen, a destructive-distillation process that creates a dark tar rich in smoky and phenolic compounds.

IFRA prohibits crude birch wood or bark pyrolysates as fragrance ingredients and specifies rectified or purified birch tar oils subject to limits on polycyclic aromatic hydrocarbons. That makes crude tar and a finished perfumery-grade birch tar material importantly different references.

What to notice

Birch tar can suggest:

• burnt wood
• campfire smoke
• tar
• charred bark
• leather
• phenolic or medicinal sharpness
• dark animalic depth

It is one of the clearest raw-material references for the historical smoky leather effect.

Birch tar and leather

Birch tar is not leather itself. Rather, its smoky-tarry smell became closely associated with traditional leather perfumery and so can form part of a leather accord.

That distinction matters for this library: Leather is an olfactory construction, while Birch Tar is a specific processed material that may help create it.

Source precision

Several birch species can be used to make tar. If the botanical source is supplied, the archive should preserve it instead of assuming every birch tar is from the same species.