McDonald's french fries, marketed as World Famous Fries,^[1] are a French fries product at the fast food restaurant McDonald's.

Introduced in 1949, the French fries were cooked in a mixture of 93% beef tallow and 7% cottonseed oil.^[2][3]

In the 1950s, CEO and founder Ray Kroc established quality control measures for McDonald's suppliers, ensuring potatoes maintained a solids content within the optimal range of twenty to twenty-three percent.^[4] Kroc also pioneered the practice of "curing" the potatoes to convert sugars to starch, thus achieving consistently crisp French fries. This process involved storing potatoes at warm temperatures for several weeks.^[4] Additionally, he introduced the "potato computer," developed by Louis Martino, to calculate the precise cooking time for fries, based on the fluctuation of oil temperature during frying.^[4] Subsequently, in 1967, Kroc contracted the Simplot company to supply them with frozen fries, replacing fresh-cut potatoes.

In the late 1980s, Phil Sokolof, a millionaire businessman who had suffered a heart attack at the age of 43, took out full-page newspaper ads in New York, Chicago, and other large cities accusing McDonald's menu of being a threat to American health, and asking them to stop using beef tallow to cook their french fries.^[5]

After this sustained campaign, including by the National Heart Savers Association against saturated fats and the beef tallow they were using,^[6][7][8] in 1990, they switched to vegetable oil with beef flavouring.^[9][2] McDonald's has not disclosed whether its beef flavouring contains meat, but it is known to contain milk byproducts.^[10] In 2002, McDonald's paid US$10 million to settle lawsuits that accused the chain of mislabeling its French fries as vegetarian.^[11]

The "thin style" French fries have been popularized worldwide in large part by McDonald's and, to a lesser extent, Burger King.^[12]

In 2008, McDonald's ceased using trans fats in both US and Canadian markets.^[9] In 2013, McDonald's Canada introduced poutine nationwide, after having it in Quebec for 10 years.^[13]

In the United States, McDonald's french fries are made using 19 ingredients, which include dextrose, TBHQ, polydimethylsiloxane, citric acid, and sodium acid pyrophosphate.^[14][15] The restaurant uses non-GMO^[16] russet and Shepody potatoes.

As of 2019, the french fries sold in Germany use a different recipe, with the ingredients being listed as potatoes, sunflower oil, rapeseed oil, salt, dextrose, disodium phosphate and polydimethylsiloxane.^[17]

As for the manufacturing process, the potatoes are first brought to the plant, where they are mechanically cut, blanched, partially fried, flash-frozen, and then shipped to individual restaurants of the franchise.^[16]