As summer heats up across the country, producers and consumers are cooling off by celebrating National Ice Cream Month this July. While vanilla remains America’s most popular flavor, the first recorded recipe, written in the 1660s, called for cream, sugar, orange flower water and ambergris, also known as whale vomit. Yum.

According to Gastropod, a podcast about food science and history, the first known recipe for ice cream was written by English noblewoman, Lady Anne Fanshawe.

In place of salt, which is used to lower the freezing temperature of the cream, Fanshawe used chunks of ambergris to help freeze and flavor this dairy treat. However, the briny ingredient has an unusual origin.

Produced by sperm whales, ambergris can be found floating atop the ocean, washed ashore or within the abdomens of the oceanic mammals. Consuming a heavy diet of giant squids, the whales are unable to digest the bone-like squid beaks.

Traveling down the whale’s intestines, the beak gathers bile and hardens to form a large mass. Eventually, the whale will expel the mass, which will then float to the top of the ocean to cure in the salt and the sun. The salt obtained from this process can then be used to help freeze and flavor the cream.

No longer used for ice cream, ambergris is now more commonly found in expensive perfumes due to its “sweet and woody” odor.

If whale vomit ice cream is not your flavor of choice, celebrate National Ice Cream Month this year by dishing up one of America’s top 10 favorite ice cream flavors according to the International Dairy Foods Association.