Castoreum is a natural flavoring used in vanilla and strawberry-flavored products. It is not a lab-created plant, nor does it have any distinctive sound. Castoreum is an excretion from the anal castor sacs of beavers. Historically, it has been utilized in medications, soaps, and food products. However, "castoreum" rarely appears on ingredient lists for items like ice cream or strawberry syrup, often being labeled as “natural flavorings.”
Despite concerns, the FDA has deemed castoreum safe, noting its long history of use without adverse human reactions. However, it is rarely used due to several factors. Firstly, it prevents products from being certified kosher. Additionally, obtaining castoreum is expensive. Flavor chemist Gary Reineccius from the University of Minnesota explains, “In the flavor industry, you need tons and tons of material to work with. It’s not like you can grow fields of beavers to harvest. There aren’t very many of them. So it ends up being a very expensive product — and not very popular with food companies.”
Michelle Francl, a chemist at Bryn Mawr College, assures that due to the high costs, beaver excretion is not secretly added to foods. Vanilla orchids, for example, are far more economical to grow and harvest on a large scale. Castoreum may be used in niche products like bäversnaps, a Swedish liquor, where it is openly advertised. The substance is harvested by trapping and killing beavers to remove their castor glands, which are then dried, ground up, and extracted with alcohol, similar to how vanilla extract is made.
Historically, castoreum has been a versatile therapeutic agent used to treat stomach issues, fevers, and mental disorders, and in making soap and lotion. It was even used in cigarettes to enhance sweetness. Castoreum contains salicylic acid, a pain-relieving component of aspirin, demonstrating its diverse applications despite its unappealing origin.
The discovery of castoreum occurred during the peak of the fur trade, nearly leading to the extinction of beavers in North America and Eurasia. By the 16th century in Europe and the 19th century in North America, the beaver population was critically endangered.
Beavers use their sac excretion to mark territories, with males typically taking on this task. It also helps identify family members as each beaver's scent is unique, and it makes their tails and fur more slick and water-resistant.
The beaver's diet of leaves, bark, and other plant material contributes to the sweet, vanilla-like aroma of castoreum. However, there is no need to worry about finding castoreum in your food under the label “natural flavorings.” As Reineccius points out, “If food companies can find anything else to substitute for vanilla or to create a strawberry flavor, they will. It actually isn’t very hard to make a basic strawberry flavor that you would recognize with just two compounds.”