Birch bud absolute

Green resin, balsam, damp wood. Young leaf and bark facets. A dry base with a hint of leather and hay.

Birch bud absolute has no dedicated standard in the 51st Amendment of the IFRA Standards. It is unrelated to sweet birch oil (Betula lenta), which is rich in methyl salicylate.

β-Caryophyllene, a common constituent of birch buds, is on the extended EU fragrance allergen list under Regulation 2023/1545. It must be labelled above 0.001 percent in leave-on or 0.01 percent in rinse-off products.

Store dark, sealed and cool.

Birch buds are picked in winter and early spring, while still closed and coated with sticky resin. This resin holds most of the aromatic matter. Once the buds open, the resin decreases.

Two species are used: silver birch, Betula pendula, and downy birch, Betula pubescens. Both are widespread in northern and eastern Europe. The buds can be steam-distilled for an oil, or solvent-extracted for a concrete and an absolute.

Analyses of Betula pendula bud oil show oxygenated sesquiterpenes in the lead. Hydroxy derivatives of caryophyllene come first. The betulenols, α-betulenol and its acetate, are a marker of the genus. β-Caryophyllene, δ-cadinene and caryophyllene oxide are also present.

In perfumery, birch bud absolute is a minor material with a clear role. It gives a green resinous note without the sweetness of tropical balsams. It suits chypres, leather accords, conifer forest accords and green leaf structures.

It should not be confused with birch tar, a smoky destructive distillate of wood and bark, nor with sweet birch oil from the bark of Betula lenta. The three differ in plant part, process and composition.