From Seed to Bottle: Seven Cooking Oils and the Fat Made from Them

Start with the general term. Vegetable oil means oils taken from the seeds or other parts of edible plants, a mixture of triglycerides that stays liquid at room temperature, pressed mechanically as olive and coconut oils traditionally are or pulled out with a solvent such as hexane for industrial soybean and corn oil. The atlas records world production rising 125 percent between 2000 and 2020 to 212 million tonnes by 2022, and the earliest-use year recorded is 6000 BC, for olive oil.

The second most consumed vegetable oil in the world shows the industrial route described in the previous stop. The beans are cracked, moistened, heated to 60 to 88 degrees Celsius, rolled into flakes and extracted with hexane before refining. The atlas notes that it has traded on the Chicago Board of Trade since 1951, and that China led 2023 output at 17.4 million tonnes of a 59.9 million tonne world total.

Palm oil is derived from the reddish pulp of the fruit of the African oil palm, not from a seed, and the atlas puts its share of global oils from oil crops at about 36 percent in 2017. People consumed an average of 7.7 kilograms of it per person in 2015, and the page records why that scale is contested, since plantation expansion is a major contributor to tropical deforestation.

Sunflower oil is pressed from sunflower seeds and is commonly used as a frying oil. The page explains that it is mainly linoleic acid, a polyunsaturated fat, and oleic acid, a monounsaturated fat, and that selective breeding can change their proportions. It has a neutral taste and a large amount of vitamin E, which is why it works as a plain frying medium.

Peanut oil, also called groundnut oil, is the first stop where flavor depends on refining: unrefined oil keeps a strong peanut taste and is used in dressings and marinades, while the refined form has a milder taste and a smoke point of about 450 degrees Fahrenheit that suits frying. Global production reached 6.4 million tonnes in 2023, with India and China supplying about two thirds. The atlas records the French experiments with producing it in Landes in 1802.

Cottonseed oil began as a worthless byproduct of the nineteenth century cotton industry. The page names William Fee's 1857 hull separator and the Procter and Gamble hydrogenation process as the innovations that made it a major cooking oil, and records that the toxin gossypol must be removed by refining, bleaching and deodorizing. David Wesson's 1899 technique made it edible, and soybean oil has since displaced it in American cooking.

Walnut oil closes the run of oils with a cold-use specialty. Pressed from Juglans regia, it is rich in linoleic acid at 58 percent, and heating dulls its flavor and can add bitterness, so it goes mainly into salad dressings. More than 99 percent of United States walnut oil comes from California. Its high price limits how widely it is used compared with the oils before it, and it is a recorded tree nut allergen.

End with the fat made from oil. Margarine is a water-in-fat emulsion, originally of animal fats and today mostly of refined vegetable oil and water, invented by the French chemist Hippolyte Mege-Mouries in 1869 after Napoleon III called for a butter substitute. The name oleomargarine comes from the Latin for olive oil and the Greek for pearl, and the page notes that unlike butter, which is made by centrifuging cream, margarine needs more intensive processing.