Violet: the shy flower perfumers rebuild with ionones

Where does violet in perfume come from?

Sweet violet, Viola odorata, grows wild across Europe south of Scandinavia, northwest Africa, the Caucasus and Western Asia. Its scent was a favourite of the late Victorian period and went into many perfumes. Yet the botanical profile of sweet violet notes that production of true violet flower extract had almost disappeared by the late 1950s, while violet leaf absolute remains widely used in modern perfumery.

What does violet smell like?

Violet flowers have a sweet scent that few other flowers resemble, and it plays a trick on you: it slightly numbs your smell receptors, so you have to wait a few minutes before you can smell it again. Violet leaf is another story, green, powdery and a little waxy. The soft violet flower note you recognise in a bottle comes from synthetic molecules.

How do perfumers recreate violet?

Violet is rebuilt with ionones, a family named after the Greek ion, violet. As the chemistry entry on ionones explains, the combination of alpha-ionone and beta-ionone is characteristic of the scent of violets. Ionones form when carotenoids break down, which is why they also turn up in rose oil and in osmanthus flowers.

Your nose may not agree with your friend's. According to the same entry, a single variation in the OR5A1 receptor makes some people about 100 times less sensitive to beta-ionone, and at high concentrations they smell something sour instead of a flower.

What should you know about violet?

Violet belongs to the florals family and shares its ionones with rose and osmanthus. One related ionone, alpha-isomethyl ionone, is on the EU list of fragrance allergens that must be named on the label above 0.001% in leave-on products, under the EU Cosmetic Products Regulation. Molecules like these are the subject of the Class on natural versus synthetic.