Oakmoss Perfumes

Methyl atrarate and atranol: the molecules in oakmoss

Oakmoss is not a moss but a lichen: Evernia prunastri, a symbiosis of a fungus and an alga. It grows on the bark of oaks and other trees. It is gathered mainly in the Balkans – for example in North Macedonia, Bulgaria and Croatia – and in Morocco, by hand, and then dried. For perfumery, the lichen is usually extracted with hexane; the resulting extract is then treated with ethanol to give the absolute. Methyl atrarate (C₁₀H₁₂O₄), also known as methyl β-orcinolcarboxylate, is regarded as an important odour carrier. The absolute, however, also contains atranol (C₈H₈O₃) and chloroatranol (C₈H₇ClO₃), two potent contact allergens. IFRA therefore requires extracts with less than 100 ppm each of atranol and chloroatranol and limits them to 0.1 % in fine fragrance; in the EU, atranol and chloroatranol have been banned in cosmetics since 2019. Today, low-atranol oakmoss and synthetic methyl atrarate are used as a replacement.

In a fragrance, oakmoss is dark green, damp and earthy – like wet bark or a forest floor after rain, with bitter, slightly leathery facets. It fixes other notes and forms the foundation of the chypre family. With bergamot it feels classic and full of contrast, with patchouli or vetiver deep and earthy, with lavender and tonka aromatic and rounded.

In this selection, oakmoss sits in the fragrance pyramid – mostly in the base note.