Sassafras: The Tree Behind Filé Powder, Root Beer and a 1960 Food Ban

Sassafras root bark once flavored root beer and sassafras tea, until the safrole in its oil led the United States to bar sassafras oil and safrole from food in 1960. In your kitchen today, sassafras means filé powder: the dried, ground leaves that season and thicken Louisiana gumbo. The tree itself, Sassafras albidum, grows in eastern North America and belongs to the laurel family. And the moment you add filé to the pot decides whether it seasons the gumbo or turns it stringy.

At a glance

Flavor and the compounds behind it

Sassafras leaves have a weak but fresh, lemony smell. Filé tastes sweet, earthy, peppery and thyme-like, and green leaves dried in the dark taste of lemon and coriander. Store-bought filé dried in sunlight is a duller green. Red filé, made from red fall leaves, tastes different because the chlorophyll is gone.

The leaf and the root are chemically different, and that’s the key to how sassafras is regulated. Here are Katzer’s figures:¹

The FDA gives the same figure for the commercial oil: oil of sassafras is about 80 percent safrole.³ Sassafras oil once flavored root beer in the United States.

Origin and history

The species is native from southeastern Canada to the central and eastern United States. It shares its family, Lauraceae, with the bay laurel that gives us bay leaves.

Katzer traces the name to Latin saxum fragans, “stone breaker,” most likely by way of Spanish, after an old use against kidney stones that he calls obsolete.¹

Indigenous communities had long drunk sassafras tea for fevers, digestive complaints and other conditions, Kari Traylor writes in JSTOR Daily. Sassafras bark became one of the main exports of the English colony at Jamestown and was harvested hard for European markets, where it was sold as a treatment for the “French pox,” syphilis. The Spanish physician Nicolás Monardes called it a universal remedy.⁵ That’s a history of belief, not evidence that it worked.

Filé has Choctaw roots. Caldwell writes that many Choctaw foods once used powdered sassafras and gives the tree’s Choctaw name as iti kʋfi.⁶ Morgan Randall, also in 64 Parishes, gives the Choctaw word for the plant and its powder as kombo. She says the Choctaw gathered and dried the leaves, and the powder thickened soups and added flavor.⁷ The two writers give different words: Caldwell’s names the tree, Randall’s the plant and its powder.

Sassafras root later flavored root beer, alongside sarsaparilla, juniper and vanilla, until the FDA banned sassafras oil and safrole as food additives in 1960.⁵³

How filé is used

Filé is one of the three common gumbo thickeners, along with okra and a flour roux. Caldwell notes that filé gumbos and okra gumbos were traditionally separate dishes, partly because okra was only around in season, and that you can make filé gumbo without a roux.⁶ Randall describes filé as what you reach for when okra isn’t in season.⁷

When you add it changes the texture:

• Stirred in off the heat or at the table. Filé added after the heat comes down seasons a gumbo, soup or stew. Most often it’s sprinkled on as a finishing garnish, and Creole and Cajun restaurants often set it out with the table condiments. You can also stir it in right before serving, with the gumbo eaten over plain rice.
• Cooked in. Added early, filé thickens the pot into a viscous, stringy consistency that looks like ropes when you pour it.

Filé is made by harvesting, drying and pounding the leaves. Louisiana filé maker John Oswald Colson and his protégé Dustin Fuqua, profiled by Randall, dry hand-picked leaves over two to three weeks and grind them with a pile and pilon into a fine, bright green powder.⁷ Store-bought blends may add bay leaves, oregano, thyme or basil. Filé belongs in the same Louisiana pantry as Cajun seasoning and Creole seasoning.

Buying and quality

Color is a good guide. Randall contrasts homemade bright green filé with the sawdust-like color and texture of commercial filé, and Caldwell links that duller green to drying in sunlight.⁷⁶ Check the label to see whether you’re getting pure sassafras leaf or a blend with other herbs. We didn’t find any grading standard for filé.

Storage

We didn’t find a shelf life for filé powder from any regulator or standards body. It’s a dried, ground leaf with its aroma in a volatile oil, so keep it sealed, cool and dark, and judge it by color and smell.

Safety and regulation

United States. Food with added safrole, oil of sassafras, isosafrole or dihydrosafrole counts as adulterated. So does a food whose main purpose is to carry them into another food; the regulation’s example is sassafras tea. The rule cites a Federal Register order of December 3, 1960.³ Two sassafras ingredients are still allowed as flavorings, both only without safrole:

• a safrole-free water extract of the root bark, made by extracting the bark, concentrating it and discarding the oily layer;²
• sassafras leaves, listed among natural flavoring substances with the limitation “safrole free.”⁴

We found no FDA statement that mentions filé powder by name.

Why safrole. The National Toxicology Program lists safrole as reasonably anticipated to be a human carcinogen, because it caused liver tumors in two rodent species. It reports no epidemiological studies of people exposed specifically to safrole. The same profile notes that several spices contain small amounts of safrole naturally.⁸ Katzer calls safrole a potent liver toxin and liver carcinogen in animals. He considers leaves and filé generally harmless in cooking amounts because their safrole content is low, and strongly discourages cooking or medical use of the root.¹ That last call is his. No regulator we found has set a safrole limit for filé.

European Union. Safrole is on the EU list of substances that can’t be added to food as such, and it has maximum levels in compound foods where it comes from flavorings:⁹

Those limits don’t apply when a food has no added flavorings and the only flavoring ingredients are fresh, dried or frozen herbs and spices.⁹

Health claims. We couldn’t trace claims that sassafras relieves pain, fights infection or boosts immunity to any credible source, so we don’t repeat them. Its long use against syphilis is documented as history, not as a treatment that worked.⁵

Substitutes and comparisons

• Sassafras substitutes
• Gumbo filé powder
• Gumbo filé substitutes
• Saffron vs. sassafras