McDonald's Used to Fry Everything in Beef Tallow. Here Is Exactly Why They Stopped — and Why It Matters.

By Savannah Ryan — The Foodie Kitchen

The year is 1990. McDonald's has just announced it is changing its frying oil. The decision is framed as a health improvement — out with the beef tallow that the chain has used since Ray Kroc opened his first restaurant in 1955, in with vegetable shortening. The health advocates who campaigned for the switch celebrate. The nutritionists nod approvingly. And across America, without anyone quite realising it yet, the best french fry in the history of fast food disappears forever.

This is the full story of that switch — what McDonald's actually fried in, who forced them to change it, what replaced it, and why the decision that was sold as a health improvement turned out to be one of the most consequential dietary mistakes of the 20th century. And at the end of this article there is a recipe for tallow fries that taste exactly like 1989 McDonald's — because the fat is the same fat.

What McDonald's Actually Fried In — The Tallow Era (1955 to 1990)

From the founding of McDonald's as a national chain in the mid-1950s through to the last day of 1989, McDonald's fried its potatoes in a blend of approximately 93 percent beef tallow and 7 percent cottonseed oil. The tallow was rendered beef kidney fat — the same fat that home cooks and professional kitchens across the world had used for centuries. It had a smoke point of approximately 420F, remained chemically stable under the sustained high heat of commercial deep fryers and — crucially — transferred its mild, clean beef flavour directly into the potato during frying.

This flavour transfer is the reason McDonald's fries were categorically different from every other fast food fry of the era. It is not nostalgia distorting memory. Food scientists who have studied the original recipe confirm that the combination of Russet Burbank potato, blanching in water, partial frying, freezing and final frying in beef tallow produced a flavour profile that has never been chemically replicated. The tallow coating the fry during cooking was doing something no laboratory flavourist could fully reproduce — it was cooking potato in beef fat the way humans have cooked starchy foods in animal fat since before recorded history. It worked because it was correct, not because it was innovative.

According to the Weston A. Price Foundation, grass-fed beef tallow contains conjugated linoleic acid, vitamins A, D, E and K2 and a saturated fat structure that is completely stable under the high heat of commercial frying. Not a single one of these properties is present in the vegetable oil that replaced it.

The Campaign That Ended the Tallow Era

In 1990 the Center for Science in the Public Interest — a Washington-based food advocacy group — launched a high-profile campaign targeting McDonald's use of beef tallow. The CSPI's argument was built on the dietary fat guidelines of the era: saturated fat raised LDL cholesterol, LDL cholesterol caused heart disease, therefore saturated animal fats like tallow were dangerous and should be replaced with polyunsaturated vegetable oils which were claimed to be heart-protective.

The science underpinning this campaign was the diet-heart hypothesis — a model of cardiovascular disease developed primarily by Ancel Keys in the 1960s and 1970s that attributed heart disease to saturated fat consumption. Subsequent research has substantially challenged this hypothesis. A 2010 meta-analysis published on PubMed reviewing 21 studies found no significant association between saturated fat intake and cardiovascular disease. A 2014 meta-analysis in the Annals of Internal Medicine reached similar conclusions. The scientific foundation of the campaign that removed tallow from McDonald's fryers has not held up to scrutiny — but the damage was already done a decade before the research caught up.

McDonald's, facing public pressure and reputational risk, announced in July 1990 that it would switch from beef tallow to 100 percent vegetable shortening. The chain framed the decision as a response to customer health concerns. It was, in practice, a capitulation to a lobbying campaign built on contested nutritional science.

What Replaced the Tallow — and the Trans Fat Catastrophe

The vegetable shortening that replaced beef tallow in McDonald's fryers in 1990 was partially hydrogenated vegetable oil — a manufactured fat created by forcing hydrogen atoms into liquid vegetable oil under pressure to make it solid and shelf-stable at frying temperatures. Partial hydrogenation produces trans fatty acids as a by-product. Trans fats are now recognised as the most harmful dietary fat category identified — more harmful than the saturated fat they replaced. The FDA banned partially hydrogenated oils from the US food supply in 2015, 25 years after McDonald's switched to them as a health improvement.

McDonald's spent the period from 1990 to 2008 frying in partially hydrogenated vegetable oil. In 2008 they switched again — this time to a canola and corn oil blend — to comply with emerging trans fat regulations. The current frying oil is a blend of canola, soybean and hydrogenated soybean oil. Every oil in that blend is a seed oil. Every one oxidises under the sustained 350F heat of a commercial deep fryer, producing the cytotoxic aldehydes and lipid peroxidation products that research on PubMed associates with inflammation and cellular damage. The beef tallow that was removed to protect public health has been replaced by two successive generations of oils that are measurably more harmful than what they replaced.

The "Natural Beef Flavouring" That Tells the Whole Story

Here is the detail that reveals everything about the 1990 switch. McDonald's US fries currently contain an ingredient listed as "natural beef flavouring" — a synthetic flavour additive derived from wheat and dairy derivatives, added to the par-fried potato strips before freezing to give the finished fry a beef-adjacent flavour note. This additive does not exist in McDonald's fries in the United Kingdom, where no flavouring is added and the fry is simply potato, oil and salt.

Read that again. McDonald's adds a synthetic flavour to American fries to approximate the taste that beef tallow produced naturally for 35 years. The fat that was removed for health reasons is now being chemically impersonated by an additive. The original solution — frying in actual beef fat — was simpler, more effective, more flavourful and, by the evidence now available, significantly healthier than the industrial oils that replaced it.

Serious Eats' analysis of McDonald's fry chemistry confirms the role of beef flavouring in the current recipe and the flavour difference between the tallow era and the present formulation.

What This Means for Your Kitchen

The McDonald's tallow story is not primarily about fast food nostalgia. It is a precise illustration of what happens when a cooking fat with thousands of years of safe, flavourful use is replaced by an industrial product created in a 20th century laboratory on the basis of nutritional science that later turned out to be wrong. The same substitution happened in home kitchens across the world at roughly the same time — lard replaced by vegetable shortening, butter replaced by margarine, tallow replaced by canola oil. The results in home cooking were the same as in McDonald's fryers: worse food and worse health outcomes.

The solution in your kitchen is exactly what McDonald's had in 1989 — beef tallow for high-heat frying, butter for moderate cooking, lard for certain baking and frying applications, olive oil for cold applications and dressings. These are not novelty ingredients. They are the original ingredients. The novelty was replacing them. According to the Weston A. Price Foundation, the 20th century shift from animal fats to seed oils is one of the most significant and damaging changes in the history of human nutrition. The evidence continues to accumulate in support of that position.

The Recipe — Tallow Fries That Taste Like 1989

Serves 4 | Prep 30 minutes including soak | Cook 15 minutes

• 1kg Russet or Maris Piper potatoes — high starch varieties only
• 1 litre beef tallow — enough to fully submerge the fries
• Fine sea salt
• Flaky salt to finish

1. Peel and cut the potatoes into 1cm batons — uniform size ensures even cooking. Place immediately into cold water as you cut. Soak for at least 20 minutes — up to 2 hours for the best result. The soak removes surface starch, which is what causes fries to stick together and prevents the exterior from crisping properly.

2. Drain and dry the potato batons completely with paper towel or a clean kitchen cloth. Any surface moisture in hot tallow will cause violent spitting. Take your time with this step.

3. Heat the tallow in a large, deep, heavy pot to 150C — use a thermometer. At this temperature the fries will cook through without colouring. Lower the fries in batches — never crowd the pot. Fry for 5 to 6 minutes until just tender and very pale gold. Remove and drain on a wire rack. This is the blanch fry. Allow to cool for at least 10 minutes — ideally 30.

4. Raise the tallow temperature to 190C. Return the blanched fries in batches. Fry for 3 to 4 minutes until deep golden and audibly crisp. The colour should be amber, not pale gold. Remove and drain immediately on the wire rack — never on paper towel, which traps steam and softens the crust.

5. Season with fine sea salt the moment they come out of the fryer — salt adheres to the tallow coating on the hot fry and will not stick once the fry cools. Finish with flaky salt at the table.

The double-fry method — blanch at 150C, rest, finish at 190C — is the technique McDonald's used in the tallow era. The low first fry cooks the interior completely. The high second fry creates the crust that the hot tallow sears onto the exterior of the potato. The result is a fry with a fully cooked, fluffy interior and a shatteringly thin, beef-flavoured crust. This is what they used to taste like. This is what food tastes like when the fat is correct.

Find beef tallow at most butcher shops, farmers markets and health food stores. Render it yourself from beef suet for the purest flavour. Store cooled tallow in a sealed glass jar — it keeps at room temperature for months and can be strained and reused multiple times.

Find more tallow recipes in the MAHA recipes collection and the complete MAHA recipe guide. For the beef tallow smash burgers — the same fat, a different application. More MAHA fast food recreations at the MAHA meal prep guide on Wix.

Frequently Asked Questions

Did McDonald's really fry in beef tallow?
Yes. McDonald's fried its potatoes in a blend of approximately 93 percent beef tallow and 7 percent cottonseed oil from the founding of the chain in the mid-1950s until 1990. The switch to vegetable shortening was announced in July 1990 following a campaign by the Center for Science in the Public Interest.

Why did McDonald's stop using beef tallow?
McDonald's switched from beef tallow to vegetable shortening in 1990 following sustained public pressure from the Center for Science in the Public Interest, which argued that saturated animal fats were harmful based on the diet-heart hypothesis of the era. Subsequent research has substantially challenged the scientific basis of that campaign.

Do McDonald's fries still have beef flavouring?
Yes. McDonald's US fries contain an ingredient listed as "natural beef flavouring" — a synthetic additive derived from wheat and dairy derivatives. This additive is not present in UK McDonald's fries, which list only potato, vegetable oil and salt. The flavouring was introduced to approximate the taste that beef tallow produced naturally before 1990.

Is beef tallow better than vegetable oil for frying?
Yes for several reasons. Beef tallow has a smoke point of approximately 420F, remains chemically stable under sustained high frying heat, does not produce the cytotoxic aldehydes that seed oils generate under the same conditions, and produces superior flavour and crunch. It also contains fat-soluble vitamins and CLA that seed oils lack entirely.

Can I fry chips in beef tallow at home?
Yes. The recipe in this article produces the closest home approximation to 1989 McDonald's fries currently achievable. Use high-starch potatoes, double-fry at 150C then 190C, dry the potatoes thoroughly before frying and season immediately with fine salt as they come out of the fat.

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