Vanilla.

True vanilla is the cured pod of a climbing orchid, hand-pollinated (the natural pollinator only exists in Mexico) and aged for six to nine months until it browns and surrenders its scent. Far from the synthetic candyfloss of cheap perfumery, real vanilla absolute is dark, leathery, almost smoky — closer to tobacco, rum and old paper than to dessert.

Madagascar vanilla is the benchmark — rich, creamy, with a hint of prune. Tahitian vanilla is more floral, almost cherry-like. Ugandan vanilla, the newer entrant, leans woody and smoky. In perfumery vanilla is the great softener, smoothing the edges off everything from oud to citrus.