Meet the Ingredient: The Peanut, A Legume From South America

October 11, 2026

Peanuts (Arachis hypogaea) grow underground and belong to the legume family, alongside beans and lentils. They are not true nuts at all, and almost everything about how they grow is a little unexpected.

A flower that plants itself

Peanut flowers open above ground. Once a flower has been pollinated, the stalk beneath it lengthens and bends downwards, pushing the flower into the soil. The pod then develops and ripens underground, which botanists call geocarpy. The Oxford University Herbaria profile says the ovary matures over three to four months into a pod holding up to four seeds. That habit explains the plant's other names, earthnut and groundnut. Roughly half the seed is oil, according to the same profile, which is why peanuts are pressed for cooking oil as well as eaten whole.

Where they come from

Peanuts are native to tropical South America and were later introduced to the tropics of the Old World, according to Encyclopaedia Britannica, and the Oxford profile says they have been cultivated in South America for more than 3,500 years. Genetics has added detail. A 2016 study in Nature Genetics sequenced the two wild diploid species, Arachis duranensis and Arachis ipaensis, that are the ancestors of the cultivated peanut. The authors conclude that the crop probably arose from a single, recent hybridisation between those two species followed by a doubling of the chromosomes. They also note that the oldest known peanut remains, from Peru, are about 7,800 years old, and that the earliest identifiable remains of the cultivated species are roughly 3,500 to 4,500 years old. Today the Oxford profile lists China, India and the United States among the largest producers.

The story of peanut butter

Peanut butter has no single inventor. The National Peanut Board notes early references to the Incas and Aztecs grinding roasted peanuts into a paste. In North America, Marcellus Gilmore Edson, a Canadian, patented a peanut paste in 1884, made by pressing roasted peanuts between heated surfaces. Dr John Harvey Kellogg was granted a patent in 1895 for making peanut butter from raw peanuts, which he promoted as a food for people who found chewing difficult, and Dr Ambrose Straub of St Louis patented a machine for producing it in 1903. George Washington Carver, often credited with the invention, did not invent it; his legacy is the many uses he promoted for the crop.

Why our peanuts are high oleic

Our butters are made from high oleic American peanuts. Oleic acid is a fatty acid with fewer double bonds in its chemistry than linoleic acid. The American Society of Agronomy explains that fats with fewer double bonds last longer before turning rancid, and that peanuts bred for high oleic content can have a much longer shelf life. In a product that is nothing but peanuts, that is a useful property.

Smooth or crunchy?

Both of our butters start the same way: the peanuts are toasted and stone milled slowly, keeping a hint of the red skin, which the product pages describe as adding a distinctive flavour. The only difference is texture.

Smooth: creamy and spoonable. It disperses easily, which makes it the better choice for sauces, smoothies and baking.
Crunchy: has roasted peanut halves added for crunch. It is best on toast, with fruit, and in sandwiches.

Both have the same nutrition per 100g, including 25g of protein.

In the kitchen

Satay-style sauce. Whisk smooth peanut butter with lime juice, garlic and soy sauce, then loosen with warm water until it pours. Add the water a little at a time so you can stop when the texture is right.
Peanut butter and banana on toast. Crunchy is the natural choice.
Oat and peanut butter cookies. Smooth gives an even dough.

Storing and stirring

Natural peanut butter has no added stabilisers, so the peanuts' own oil rises to the top of the jar. The Canadian Food Inspection Agency says this separation is completely natural. Stir the oil back in, or store the jar upside down for a while and then turn it the right way up. Keep it in a cool, dry place and use within 3 months of opening.