Question sent by JAIME LÁZARO (Manises). JUAN ANTONIO RAGA ESTEVE answers:
Ambergris grows inside the intestine of sperm whales and thus it is part of its faeces. It is formed by the remains of the jaws of eaten squids, together with the actions of liquids and bacteria present in the intestine. Therefore, it has an unpleasant faecal smell. However, its physical and chemical properties (soluble in alcohol but not in water) allow it to float and it acquires a sweet odour over time (years). That is why it can unusually be found on beaches or in the carcasses of sperm whales. But the most interesting thing is the fact that it fixates perfumes quite well. In fact, it was very valued as a perfume fixative. Nowadays, synthetic derivatives such as ambrox are used to this effect.
Juan Antonio Raga Esteve. Animal Biology Department and Institut Cavanilles of Biodiversity and Evolutive Biology. Universitat de València.