Like an oyster makes a pearl to protect its insides from an irritant, a sperm whale makes ambergris to protect its insides from irritating parts of food it can’t digest, such as squid beaks. The whale excretes (ahem, poops) its brick of waxy mucus, leaving it to float in the ocean for years and decades, its scent becoming more and more refined as it “cures” in the salt water and sunlight—this is essential; ambergris fresh from the whale is no good. Eventually a sailor may scoop it up or a lucky passerby out for a beach stroll may find it washed up on the shore. Ambergris looks, basically, like a rock. Originally it was used (generally powdered and/or tinctured) as flavoring or in medicines, including the allegedly plague-dispelling “pomanders” that were filled with aromatic materials and worn around the neck—the word comes from the French “pommes d’ambre”: ambergris apples. Eventually the enchanting substance came to be used in perfume.
In her book Fragrant: The Secret Life of Scent, Mandy Aftel writes that “…ambergris remains one of the great mysteries of perfumery; a fixative of great value, it is long-lasting and mellowing. Used in small quantities, it creates an exalting and shimmering effect on the entire perfume. Sweet and dry, with stronger notes of wood, moss, and amber, it has only a slight animal aroma.” Steffen Arctander in his Perfume and Flavor Materials of Natural Origin writes of ambergris (listed as “Ambra”): “Its odor is rather subtle, reminiscent of seaweed, wood, moss, with a peculiar sweet, yet very dry undertone of unequaled tenacity.”
While ambergris from a sperm whale can in some ways be compared to pearls from an oyster, ambergris cannot be cultivated the way pearls can—which makes supply irregular and the exact qualities of scent inconsistent from one chunk or tincture to the next. Sperm whale populations are not endangered, but they are vulnerable, which means fewer mucus bricks excreted into oceans. True ambergris has been replaced by a variety of synthetic aroma molecules in most of perfumery—save, perhaps, for a few small-batch artisans dedicated to working with fine natural materials.