A Brief History of Castoreum, the Beaver Butt Secretion Used as Flavoring


In September 2013, popular blogger “The Food Babe” released a video proclaiming that beavers “flavor a ton of foods at the grocery store with their little butthole!" Since then, the internet has been crowded with alarmist posts saying that beaver’s butts are used to flavor everything from soft drinks to vanilla ice cream. The culprit behind this scare is a flavorant called castoreum—but what exactly is it, and is it worth all the fuss?


Castoreum is a substance secreted by male and female Alaskan, Canadian, and Siberian beavers from pouchlike sacs located near the base of their tails (castor is the word for beaver in Latin). Beavers can’t see or hear very well, but they have a great sense of smell—and as a result of their castoreum glands, they also smell great. They use their castoreum in part to mark their territory, secreting it on top of mounds of dirt they construct on the edges of their home turf. (The castoreum squirting out is apparently so loud, you can hear it if you’re standing nearby.) Beavers also use the fatty, waxy secretion to waterproof their fur.

An odorous combination of vanilla and raspberry with floral hints, castoreum carries information about a beaver’s health and helps to make distinctions between family members and outsiders. Beavers are so interested in the smell that historically, fur trappers would bait traps with castoreum.


Dried castoreum on display in a German museum
Dried castoreum on display in a museum.

When castoreum is fresh, it’s a fluid that ranges in color from yellow and milky to grey and sticky, depending on the type of beaver and its gender. In a live animal, this fluid is milked and dried to a solid for perfume making. In a dead animal, the entire castoreum gland is removed and, traditionally, preserved by smoking it over a wood fire.

For much of its history, castoreum was used as a medicine. Roman women inhaled the fumes of castoreum burned in lamps because they believed it would induce abortions (it didn’t). Hildegard von Bingen, a 12th-century Benedictine abbess, mystic, and scholar, wrote that powdered beaver “testicles” drunk in wine would reduce a fever; the castoreum gland, when dried, is easily mistaken for testes. Castoreum has also been used to treat headaches, which makes sense given that it contains salicylic acid, the main ingredient in aspirin.

The colonization of America led into an increase in the availability of beaver pelts, which were used to make fine hats all over Europe, and to a resurgence of interest in castoreum as medicine. Sold in drugstores and pharmacies, it was recommended for earaches, toothaches, colic, gout, inducing sleep, preventing sleep, and general strengthening of the brain. It was also in the 19th century that the substance began to be used in the perfume industry as a fixative—an ingredient that makes other scents smell better and last longer.

By the end of the 19th century, the demand for pelts and castoreum was so great that North American beavers were on the edges of extinction. In 1894, a representative of the Hudson Bay Company, a major beaver pelt and castoreum trading firm, said: "The beaver’s days are numbered. He cannot coexist with civilization.”


According to The Oxford Companion to Sugar and Sweets, castoreum was first used as a food additive in the early 20th century, but is now rarely, if ever, used in the mass-produced flavor industry. Nevertheless, the FDA considers it a “natural flavor,” since it is derived from a natural source, and can be used to add fruity strawberry or raspberry notes, or as substitute for vanilla (the compounds come from the beaver's diet of bark and leaves). One of the few places it's reliably found is the Swedish schnapps BVR HJT.

Beavers are generally no longer hunted for their pelts or castoreum, so to acquire the sticky stuff, beavers must be anesthetized and the castoreum gland milked by a human. The process was described as “pretty gross” by Joanne Crawford, a wildlife ecologist at Southern Illinois University who is no stranger to beaver butts; she noted that the goo has a consistency somewhat like molasses. Due to the inconvenience and expense of harvesting castoreum from live beavers, the substance is now seldom used. According to Fenaroli’s Handbook of Flavor Ingredients, the annual industry consumption is very low—around 300 pounds—whereas the consumption of natural vanillin is over 2.6 million pounds annually. When castoreum is used, it's far more likely to be in the profitable fragrance industry rather than in the foods we eat.

"In the flavor industry, you need tons and tons of material to work with," flavor chemist Gary Reineccius told NPR's The Salt. "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."

So while it's hard to know what foods or fragrances contain castoreum, there is very little of it out there. It may be worth saving your alarm for another topic—or simply sparing a thought for the beaver.

Just Two Cans of Soda a Day May Double Your Risk of Death From Heart Disease

If you've been stocking your refrigerator full of carbonated corn syrup in anticipation of warmer weather, the American Heart Association has some bad news. The advocacy group on Wednesday released results of research that demonstrate a link between consumption of sugary drinks—including soda, fruit juices, and other sweetened beverages—and an increased risk of dying from heart disease.

Study participants who reported consuming 24 ounces or more of sugary drinks per day had twice the risk of death from coronary artery disease of those who averaged less than 1 ounce daily. There was also an increased risk of death overall, including from other cardiovascular conditions.

The study, led by Emory University professor Jean Welsh, examined data taken from a longitudinal study of 17,930 adults over the age of 45 with no previous history of heart disease, stroke, or diabetes. Researchers followed participants for six years, and examined death records to determine causes. They observed a greater risk of death associated with sugary drinks even when they controlled for other factors, including race, income, education, smoking habits, and physical activity. The study does not show cause and effect, the researchers said, but does illuminate a trend.

The study also noted that while it showed an increased risk of death from heart disease, consumption of sugary foods was not shown to carry similar risk. One possible explanation is that the body metabolizes the sugars differently: Solid foods carry other nutrients, like fat and protein, that slow metabolism, while sugary drinks provide an undiluted influx of carbohydrates that the body must process.

The news will likely prove troublesome for the beverage industry, which has long contended with concerns that sugary drinks contribute to type 2 diabetes and tooth decay. Some cities, including Seattle, have introduced controversial "soda tax" plans that raise the sales tax on the drinks in an effort to discourage consumption.

5 Ways to Define a Sandwich, According to the Law

It’s easy to say what a sandwich is. Grilled cheese? Definitely a sandwich. Bacon, lettuce, and tomato? There’s no question. Things start to get messy when you specify what a sandwich isn’t. Is a hot dog a sandwich? What about a burrito, or an open-faced turkey melt?

The question of sandwich-hood sounds like something a monk might ponder on a mountaintop. But the answer has real-world implications. On several occasions, governments have ruled on the food industry’s right to use the delectable label. Now, Ruth Bader Ginsburg—pop culture icon, scrunchie connoisseur, and Supreme Court Justice—has weighed in on the matter.

When pressed on the hot-button issue as to whether a hot dog is a sandwich while appearing on The Late Show with Stephen Colbert, Ginsburg proved her extreme judiciousness by throwing the question back at Colbert and asking for his definition of sandwich before making a ruling. Her summation? A hot dog fits Colbert's definition of a sandwich, and therefore can be considered one.

While RBG's ruling may not be an official one, it matches Merriam-Webster's bold declaration that a hot dog is a sandwich (even if the Hot Dog Council disagrees). Officially, here’s where the law stands on the great sandwich debate.


Hot dogs are often snagged in the center of the sandwich semantics drama. Despite fitting the description of a food product served on a bread-like product, many sandwich purists insist that hot dogs deserve their own category. California joins Merriam-Webster in declaring that a hot dog is a sandwich nonetheless. The bold word choice appears in the state’s tax law, which mentions “hot dog and hamburger sandwiches” served from “sandwich stands or booths.” Applying the sandwich label to burgers is less controversial, but it’s still worth debating.


When Qdoba threatened to encroach on the territory of a Panera Bread in Shrewsbury, Massachusetts, the owners of the bakery franchise fought back. They claimed the Mexican chain’s arrival would violate their lease agreement with the White City Shopping Center—specifically the clause that prohibits the strip mall from renting to other sandwich restaurants. “We were surprised at the suit because we think it’s common sense that a burrito is not a sandwich,” Jeff Ackerman, owner of the Qdoba franchise group, told The Boston Globe.

The Worcester County Superior Court agreed. When the issue went before the court in 2006, Cambridge chef and food writer Christopher Schlesinger testified against Panera [PDF], saying, “I know of no chef or culinary historian who would call a burrito a sandwich. Indeed, the notion would be absurd to any credible chef or culinary historian.”

Justice Jeffrey A. Locke ruled that Qdoba would be allowed to move into the shopping center citing an entry in Merriam-Webster as the most damning evidence against Panera’s case. “The New Webster Third International Dictionary describes a ‘sandwich’ as ‘two thin pieces of bread, usually buttered, with a thin layer (as of meat, cheese, or savory mixture) spread between them,’” he said. “Under this definition and as dictated by common sense, this court finds that the term ‘sandwich’ is not commonly understood to include burritos, tacos, and quesadillas.”


If you want to know the definition of a certain dish, the officials at the U.S. Department of Agriculture are good people to ask. It’s their job to make sure that the nation’s supply of meat is correctly labeled. When it comes to sandwiches, the agency follows strict criteria. “A sandwich is a meat or poultry filling between two slices of bread, a bun, or a biscuit,” Mark Wheeler, who works in food and safety at the USDA, told NPR. His definition comes from the Food Standards and Labeling Policy Book used by the department (the USDA only covers the “labeling of meat, poultry, and egg products,” while the FDA handles everything else, which is why the USDA's definition excludes things like grilled cheese). Not included under their umbrella of foodstuff served between bread are burritos, wraps, and hot dogs.


The USDA’s definition may not be as simple and elegant as it seems. A sandwich is one thing, but a “sandwich-like product” is different territory. The same labeling policy book Mark Wheeler referred to when describing a sandwich lumps burritos into this vague category. Fajitas “may also be” a sandwich-like product, as long as the strips of meat in question come bundled in a tortilla. Another section of the book lists hot dogs and hamburgers as examples of sandwich-type products when laying out inspection policies for pre-packaged dinners. So is there an example of a meat-wrapped-in-carb dish that doesn’t belong to the sandwich family? Apparently strombolis are where the USDA draws the line. The Food Standards and Labeling Policy Book clearly states the product “is not considered a traditional sandwich” [PDF].


When it comes to sandwiches, New York doesn’t discriminate. In a bulletin outlining the state’s tax policy, a description of what constitutes a sandwich warrants its own subhead. The article reads:

“Sandwiches include cold and hot sandwiches of every kind that are prepared and ready to be eaten, whether made on bread, on bagels, on rolls, in pitas, in wraps, or otherwise, and regardless of the filling or number of layers. A sandwich can be as simple as a buttered bagel or roll, or as elaborate as a six-foot, toasted submarine sandwich.”

It then moves on to examples of taxable sandwiches. The list includes items widely-believed to bear the label, like Reubens, paninis, club sandwiches, and peanut butter and jelly sandwiches. Other entries, like burritos, gyros, open-faced sandwiches, and hot dogs, may cause confusion among diners.


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