Violet

Powdery, sweet and delicately floral, with a cool, slightly woody undertone.

The sweet violet, Viola odorata, is a small, low-growing perennial of the violet family. It is native to Europe and western Asia and, in the wild, flowers in early spring. In the 19th century Toulouse became the city of violets: from 1854, family growers there cultivated the double Parma violet and sent the flowers as far as Paris. In Tourrettes-sur-Loup near Grasse, violets have been the main crop since the 1880s, today above all the richly scented variety ‘Victoria’. Most of the violet leaf used in perfumery now comes from Egypt, which supplies around 90% of the world’s volume.

The flowers yield only a tiny amount of scented oil, which is why violet flower absolute was among the most expensive materials in perfumery. Today the typical violet scent comes from ionones synthesised from citral and acetone: first pseudoionone forms, which acid then closes into the ring of ionone. Usually only the leaf is natural – in Tourrettes-sur-Loup the leaves are cut from May to July and taken to Grasse the same day. There they are extracted with volatile solvents into a concrete and then purified into the dark green violet leaf absolute.

Violet lends a fragrance a powdery, sweet-floral and slightly woody softness. Violet leaf absolute, by contrast, brings a fresh, cucumber-green accent that enlivens green and fruity compositions. The violet accord is particularly close to iris, whose odorants, the irones, are close chemical relatives of the ionones. In our range it sits in the heart of 66 out of 83 fragrances.

Floral · Powdery · Green (violet leaf)

On the Côte d’Azur the sweet violet flowers from October to March, while the leaves for perfumery are cut in summer, from May to July. The violet accord itself is available all year round, as its ionones are made synthetically.

In our fragrances, it often appears alongside Vanilla, musk, bergamot, jasmine, cedarwood, sandalwood, patchouli.

Violets were already prized and made into scents in ancient Greece. In the 19th century violet fragrances became the height of fashion and Grasse processed both flowers and leaves, but the flower oil was scarce and one of the most precious materials in perfumery. In 1893 the German chemists Ferdinand Tiemann and Paul Krüger set out to uncover the secret of violet scent – to do so they studied the similar-smelling but far cheaper oil of orris root, found the irones in it and synthesised ionone for the first time. Their work is regarded as one of the founding moments of modern aroma chemistry; the ionones took their name from the Greek word “ion” for violet. Ever since, violet fragrances have been built with ionones, flower growing for perfumery has declined sharply, and today it is mainly the leaf that is still extracted naturally.

• How strongly a person perceives β-ionone, the key molecule of violet scent, depends largely on a single variant of the olfactory receptor gene OR5A1.
• In search of violet scent, Tiemann and Krüger studied of all things orris root in 1893 – and discovered the irones and ionone along the way.
• The main odorant of the violet leaf, 2,6-nonadienal, is the same one that gives cucumbers their typical smell.

Violet scent rests mainly on α- and β-ionone – they form when enzymes oxidatively split carotenoids such as β-carotene. β-Ionone (C₁₃H₂₀O, PubChem CID 638014, CAS 79-77-6, molar mass about 192 g/mol) and α-ionone (C₁₃H₂₀O, PubChem CID 5282108, CAS 127-41-3) are isomers, differing only in the position of a double bond in the ring. β-Ionone is by far the stronger odorant: the nose detects it at a concentration around 30 times lower than α-ionone. The irones of iris (α-irone: C₁₄H₂₂O, CAS 79-69-6) are chemically methyl ionones, carrying one extra carbon atom. In violet leaf, by contrast, an entirely different molecule dominates: (2E,6Z)-2,6-nonadienal (C₉H₁₄O, PubChem CID 643731, CAS 557-48-2, molar mass about 138 g/mol), known as “violet leaf aldehyde” because of where it occurs. It is also the key odorant of cucumber and smells green, fatty and fresh.