RESEARCH
Which fast food fries are cooked in beef tallow?
Five major U.S. fast-food chains use beef-derived ingredients in their fries: Steak 'n Shake, Portillo's, Bojangles, Smashburger, and McDonald's (via natural beef flavor only, not tallow). Every other major chain on Frypedia fries in plant-based oil. Here's the full per-chain breakdown.
| Chain | What's in the fry | Status |
|---|---|---|
| Steak 'n Shake | 100% beef tallow | Switched January 2025 |
| Portillo's | Vegetable oil + beef tallow blend; shared filtration | Long-standing |
| Bojangles | Canola oil + beef fat blend | Long-standing |
| Smashburger | Beef tallow + canola blend | Long-standing |
| McDonald's | Vegetable oil with "natural beef flavor" (derived from milk + hydrolyzed wheat — not tallow itself) | Beef flavor only since 1990 |
Two different things called "beef tallow"
The phrase covers two distinct preparations. Actual beef tallow — rendered beef fat used as a frying medium — is what Steak 'n Shake, Portillo's, Bojangles, and Smashburger use. Natural beef flavor — a flavoring derived from milk and hydrolyzed wheat that mimics the taste of the original 1948-1990 McDonald's fry — is what's in U.S. McDonald's fries today. The fries are not cooked in tallow, but they taste like they once were. Both preparations disqualify the fry for vegans and vegetarians; only actual tallow disqualifies it as a "plant-based oil" by industry definition.
The short history.
For most of the 20th century, beef tallow was the standard frying fat in American fast food. McDonald's "Formula 47," the original fry recipe from the 1948 founding through 1990, was a 93/7 blend of beef tallow and cottonseed oil. The taste of the postwar American french fry was, fundamentally, the taste of beef fat.
The switch to vegetable oil started in 1990, driven by a public-health campaign from millionaire Phil Sokolof targeting saturated fat. Within a few years, almost every major chain had moved to a vegetable-oil blend. The sole holdouts were a handful of regional chains (Portillo's in Chicago, Bojangles in the Southeast, Smashburger as a later entrant, and a few independents) plus the Steak 'n Shake situation, which is unusual: the chain switched to vegetable oil along with the rest of the industry, then reverted to 100% beef tallow in January 2025 as part of the broader "tallow reversion" movement.
For the editorial backstory on why a small reversal toward animal fats is happening in 2025-2026, see The tallow reversion.
FAQ
Does McDonald's use beef tallow in their fries?
Not since 1990. Today, McDonald's U.S. fries are cooked in a vegetable oil blend (canola, corn, soybean, hydrogenated soybean), to which "natural beef flavor" is added — itself derived from milk and hydrolyzed wheat. The fries taste beef-adjacent because the flavoring is engineered to mimic the original tallow-fried recipe, but actual beef tallow is no longer used in U.S. preparation. Periodic rumors of a "tallow comeback" at McDonald's have not materialized as of April 2026.
When did McDonald's stop using beef tallow?
In 1990. The switch was driven by a sustained public-health campaign from Nebraska millionaire Phil Sokolof, who took out full-page ads accusing fast-food chains of "poisoning America" with saturated fat. McDonald's was the first major chain to capitulate and move to a 100% vegetable oil blend. Most other chains followed within a few years. The "natural beef flavor" was added to the new formula to preserve the original taste profile.
Does In-N-Out use beef tallow?
No. In-N-Out uses 100% sunflower oil and has confirmed this repeatedly when social-media rumors suggest otherwise. The Kennebec potatoes are hand-cut in-store and fried in a dedicated sunflower-oil fryer. No beef, no tallow. As of April 2026, the chain has no announced plans to change.
Does Five Guys use beef tallow?
No. Five Guys uses 100% peanut oil exclusively, with a strict three-ingredient fry recipe (potatoes, peanut oil, salt). No beef, no tallow, no shared fryer with other items.
Does Wendy's use beef tallow?
No. Wendy's Natural-Cut Sea Salt fries are cooked in a vegetable oil blend (soybean, canola, cottonseed, sunflower, corn) with no beef-derived ingredients in the fry itself.
Does Burger King use beef tallow?
No. Burger King's fries are coated in a rice-flour-based batter (not wheat), then cooked in a vegetable oil blend (soybean, canola, palm). No beef, no tallow.
Does Chick-fil-A use beef tallow?
No. Chick-fil-A's Waffle Potato Fries are cooked in canola oil in a fryer dedicated to potato products. The chain's chicken uses peanut oil in a physically separate fryer. No beef-derived ingredients in either preparation.
Why did Steak 'n Shake switch back to beef tallow in 2025?
Steak 'n Shake announced the switch to 100% beef tallow in January 2025 as part of a broader brand repositioning around "the way fries used to taste." The decision was framed both as nostalgia (the original 1934 recipe used beef tallow) and as a response to growing customer interest in animal fats over seed oils. The chain is currently the most prominent national operator to fry exclusively in tallow. See The tallow reversion for the cultural context.
What is "natural beef flavor" in McDonald's fries?
Natural beef flavor is a manufactured flavoring designed to give McDonald's vegetable-oil-fried fries the taste of the pre-1990 tallow-fried fries. Per McDonald's own ingredient disclosure, the flavor is derived from hydrolyzed wheat and hydrolyzed milk as starting ingredients — meaning it contains both wheat and dairy derivatives. This is why McDonald's U.S. fries are not vegan, not vegetarian by some standards (depends on whether the source culture or final product matters to the diner), and not gluten-free (per celiac standards) or dairy-free.
Are beef-tallow fries vegetarian?
No. Beef tallow is rendered beef fat — the actual product of an animal. Fries cooked in beef tallow are not vegetarian by any standard definition. The five chains that use beef in fry preparation are all disqualified for both vegetarian and vegan diets, though the case is most clear-cut for the four that use actual tallow (Steak 'n Shake, Portillo's, Bojangles, Smashburger). McDonald's natural-beef-flavor case is grayer: there's no beef in the final product, but the flavoring is animal-derived.
Is beef tallow healthier than seed oils?
The nutritional consensus is contested and changing. Beef tallow is high in saturated fat (~50%), which traditional dietary guidance has flagged as cardiovascular risk; seed oils are higher in polyunsaturated fats and omega-6, which a more recent line of research argues may also have health costs at high consumption levels. Frypedia is editorially neutral on the broader debate — we report what each chain uses and the dietary implications, not which is "better." For most people, the difference between fast-food fry oils is small compared to total fat intake from all sources.
What's the difference between beef tallow and beef fat?
Tallow is the rendered (heated and clarified) form of beef fat — the product of cooking beef trimmings until the fat melts and separates, then filtering. Raw beef fat is the unprocessed material. In fast-food preparation, "beef tallow" almost always refers to the rendered form because it's stable, has a high smoke point, and stores well. When Bojangles lists "beef fat blend," they mean blended tallow.
Related reads
- The tallow reversion — the cultural backstory on the partial seed-oil-to-tallow swing
- The seed oil panic — what's actually known and what isn't
- Culver's vs Steak 'n Shake — same Midwestern crinkle-cut, opposite oil philosophies
- Which fries are vegan? — the eight chains where animal products are completely absent
Full chain directory: Browse all 54 chains · Research hub: Research