Bar Keepers Friend is a powdered cleaning product made by SerVaas Laboratories in the United States. Invented by a Central Indiana chemist in 1882, it has since become the base of a line of cleaning products by SerVaas, who started producing and carrying the product under the Bar Keepers Friend name in the 1950s. Unlike similar abrasive cleaning products, such as Comet and Ajax, Bar Keepers Friend uses oxalic acid as its active ingredient.