Peanut butter has ancient roots: the Incas ground peanuts into a paste; then it made a reappearance in the modern world. American John Harvey Kellogg, a doctor, nutritionist and cereal pioneer, filed a patent for a proto-peanut butter in 1895. It was promoted as a healthy alternative to meat. An elite clientele established his peanut butter as a delicacy.
Modern peanut butter enthusiasts would likely find Kellogg’s compound bland. Good Housekeeping magazine wrote that women should make their own using a meat grinder and suggested pairing it with bread.
In 1904, C.H. Summer introduced peanut butter at the St. Louis World Fair, and the product entered the mainstream. In the meantime Joseph Rosefield developed a way to prevent oil separation. In the early 1920s he created the Skippy brand.
During wartime peanut butter was vital as a protein source, and the peanut butter and jelly sandwich made its debut.
Peanut butter should be discarded if signs of rancidity like a metallic smell, off-ta...