Peanut butter is a food paste or spread made from ground dry roasted peanuts. It often contains additional ingredients that modify the taste or texture, such as salt, sweeteners or emulsifiers. Peanut butter is popular in many countries. The United States[1] is a leading exporter of peanut butter and itself consumes $800 million of peanut butter annually.[2]

Peanut butter is served as a spread on bread, toast or crackers, and used to make sandwiches (notably the peanut butter and jelly sandwich). It is also used in a number of confections, such as peanut-flavoured granola bars or croissants and other pastries. A variety of other nut butters are also sold, such as cashew butter and almond butter, produced in comparable ways.

The use of peanuts dates to the Aztecs and Incas,[3][4] and peanut paste may have been used by the Aztecs as a toothache remedy in the first century of the Common Era (CE).[5][6]

Marcellus Gilmore Edson (1849 – 1940) of Montreal, Canada obtained a patent for peanut butter in 1884.[7] Edson's cooled product had "a consistency like that of butter, lard, or ointment" according to his patent application which described a process of milling roasted peanuts until the peanuts reached "a fluid or semi-fluid state". He mixed sugar into the paste to harden its consistency. A businessperson from St. Louis named George Bayle produced and sold peanut butter in the form of a snack food in 1894.[8]

John Harvey Kellogg, known for his line of prepared breakfast cereals, was issued a patent for a "Process of Producing Alimentary Products" in 1898, and used peanuts, although he boiled the peanuts rather than roasting them.[9] Kellogg's Western Health Reform Institute served peanut butter to patients because they needed a food that contained a lot of protein, yet which could be eaten without chewing.[8] At first, peanut butter was a food for wealthy people, as it became popular initially as a product served at expensive health care institutes.[8]