Peanut butter actually dates back to Aztec times. The Aztecs mashed roasted peanuts into a paste, somewhat different from what we know of as peanut butter today. But many people have been credited with the title of peanut-butter-inventor, among them George Washington Carver. However, he did not invent peanut butter; instead he promoted more than 300 uses for peanuts, among other crops such as soy beans and sweet potatoes.
The actual invention of peanut butter, its process of manufacture and the machinery used to make it, can be credited to at least three doctors/inventors. In 1884 Marcellus Gilmore Edson of Canada patented peanut paste, the finished product from milling roasted peanuts between two heated surfaces.
In 1895 Dr. John Harvey Kellogg (the creator of Kellogg’s cereal) patented a process for creating peanut butter from raw peanuts. He marketed it as a healthy protein substitute for patients without teeth.
In 1903, Dr. Ambrose Straub of St. Louis, Missouri, patented a peanut-butter-making machine.
In 1922, chemist Joseph Rosefield invented a process for making smooth peanut butter that kept the oil from separating by using partially hydrogenated oil. In 1928 he licensed his invention to the company that created Peter Pan peanut butter. In 1932 he began producing his own peanut butter under the name Skippy.