Peanut butter contain at least 90% peanuts; the remaining <10% usually consists of "...salt, a sweetener, and an emulsifier or hardened vegetable oil which prevents the peanut oil from separating". In the US, no product labelled as "peanut butter" can contain "artificial sweeteners, chemical preservatives, [or] natural or artificial coloring additives." Some brands of peanut butter are sold without emulsifiers that bind the peanut oils with the peanut paste, and so require stirring after separation. Most major brands of peanut butter add white sugar, but there are others that use dried cane syrup, agave syrup, or coconut palm sugar. Organic and artisanal
Butter sauce with meat and vegetables. In antiquity, butter was used for fuel in lamps as a substitute for oil. The "Butter Tower" of Rouen Cathedral was erected in the early 16th century when Archbishop Georges d'Amboise authorized the burning of butter instead of oil, which was scarce at the time, during Lent. Across northern Europe, butter was sometimes treated in a manner unheard-of today: it was packed into barrels (firkins) and buried in peat bogs, perhaps for years. Such "bog butter" would develop a strong flavor as it aged, but remain edible, in large part because of the unique cool,