The tallow reversion.

Until 1990, McDonald's french fries were cooked in a blend that was 93% beef tallow and 7% cottonseed oil. A full order of fries contained roughly 10 grams of saturated fat, mostly from animal sources, and according to people who lived through the era, they tasted completely different from what they taste like now.

Then came July 1990. A nutrition advocate named Phil Sokolof, who had survived a heart attack and founded the National Heart Savers Association, ran full-page ads in the New York Times and Washington Post accusing McDonald's of poisoning America with saturated fat. Within a week, McDonald's announced it would switch to 100% vegetable oil. Burger King followed within the month. Wendy's followed within the year. The tallow era of American fast food — which stretched back more than half a century — was over in a single quarter.

Except it wasn't. Not for everyone, and increasingly, not at all.

The chains that never switched.

Five chains on Frypedia still cook fries in beef tallow today. Three are regional holdouts; two are modern chains that chose tallow as a differentiator.

Steak 'n Shake. Diner-era origin (1934). Beef tallow is part of the chain's proposition — Steakburgers cooked on a flat-top, Shoestring Fries cooked in beef fat, the whole thing a cohesive 1950s American diner experience. The chain has gone through bankruptcy and ownership changes; the tallow has survived every one.

Bojangles. A Southeast regional that commits to beef tallow the way Chick-fil-A commits to peanut oil. Part of the brand, not a cost-saving measure. Fries called "Bo-Tato Rounds" — pillowy, highly seasoned, unmistakably animal-fat-fried.

Portillo's. Chicago institution since 1963. Beef is everything — the Italian beef sandwich is the brand. Fries cooked in tallow are continuous with that identity.

Smashburger. Founded 2007. Beef tallow was never a tradition for Smashburger; the founder chose it from day one as a flavor position. When McDonald's had exited tallow, Smashburger explicitly entered it. Their FAQ still names "beef tallow/canola oil" as the fry medium.

McDonald's. The chain that triggered the 1990 reversal still adds "natural beef flavor" to its fries — a flavoring derived from beef tallow, added during the manufacturing process to approximate the pre-1990 taste. The fries aren't cooked in tallow anymore, but they are, in a legal-but-unexpected sense, flavored with it. A thirty-five-year compromise that mostly nobody outside the vegetarian community knows about.

Why it's coming back.

Three forces are converging, and you can see the trend line clearly if you look.

Force one: the seed-oil skepticism movement. Starting around 2020, a loose coalition of biohackers, functional-medicine writers, and Instagram-adjacent nutrition voices began framing industrial seed oils (soybean, canola, corn, sunflower) as the hidden villain of metabolic disease. Whether the science supports this is contested — the evidence is genuinely mixed, and the most rigorous meta-analyses still favor the American Heart Association's position that saturated fat is the bigger problem. But the cultural effect has been powerful. A large subset of wellness-minded Americans now prefer beef tallow, ghee, lard, and coconut oil to vegetable-derived oils, and they'll pay more for it.

Force two: the "real food" aesthetic. Steak 'n Shake is doing better in 2024-2026 than it has in fifteen years. Its communications increasingly lean into tallow as a feature — "we still cook our fries in beef tallow like the great American diners of the 1950s." This is positioning, and it works. For a generation that grew up eating fries that were, by their grandparents' standard, weirdly bland, the promise of "actual beef flavor in the oil" is genuinely novel.

Force three: the anti-industrial backlash. Beef tallow is a byproduct of cattle ranching — rendered fat that would otherwise be waste. It's ingredient transparency at its simplest. Compared to a proprietary blend of modified soybean oil with added antifoaming agents and natural beef flavor, "tallow" is a shorter and easier word to understand. Some chains are leaning into that clarity.

The cost to our readers.

Frypedia exists largely because fast-food fries are a minefield for anyone with a diet restriction, and the beef tallow reversion makes that minefield bigger. Specifically:

Vegetarians lose these chains entirely. Fries at Steak 'n Shake, Bojangles, Portillo's, and Smashburger are not vegetarian. McDonald's fries contain beef-derived flavoring and are therefore also not vegetarian despite being cooked in vegetable oil. For a vegetarian diner at one of these five chains, fries are not an option.

Jewish diners keeping kashrut lose them equally. Beef tallow from non-kosher sources is trefa; there's no version of the preparation that's compatible with a kosher diet.

Muslim diners should treat these five chains with caution. Halal-sourced beef tallow does exist, but none of the five tallow-using chains source it that way. Fries at these chains are not halal.

Celiacs actually benefit in one specific way: beef tallow doesn't contain gluten. But the broader fryer-sharing problem still applies — Smashburger, Steak 'n Shake, and Bojangles all fry breaded chicken and onion rings in the same tallow, reintroducing wheat cross-contact.

Vegans lose them absolutely and without qualification.

A quiet prediction.

We think this list is going to grow. The economic and cultural logic points in one direction: we expect at least one or two additional chains to switch to tallow in the next thirty-six months, either quietly (by changing the recipe and updating the allergen sheet three revisions later) or loudly (by announcing it as a brand move).

Our commitment: whenever any chain on Frypedia changes its fry oil, we update the page within forty-eight hours of confirmation. If you see a chain switch and we haven't caught it, email corrections@frypedia.com. We prioritize formulation changes above any other type of correction.

For now, the Tallow Club is five. Watch this space.