Condensed milk
Condensed milk is cow's milk from which water has been removed (roughly 60% of it). It is most often found with sugar added, in the form of sweetened condensed milk (SCM), to the extent that the terms "condensed milk" and "sweetened condensed milk" are often used interchangeably today. Sweetened condensed milk is a very thick, sweet product, which when canned can last for years without refrigeration if not opened. The product is used in numerous dessert dishes in many countries. A related product is evaporated milk, which has undergone a lengthier preservation process because it is not sweetened. Evaporated milk is known in some countries as unsweetened condensed milk. Both products have a similar amount of water removed. According to the writings of Marco Polo, in the thirteenth century the Tatars were able to condense milk. Marco Polo reported that of milk paste was carried by each man, who would subsequently mix the product with water. However, this probably refers to the soft Tatar curd (katyk), which can be made into a drink (ayran) by diluting it, and therefore refers to fermented, not fresh, milk concentrate. Nicolas Appert condensed milk in France in 1820, and Gail Borden Jr., in the United States in 1853, in reaction to difficulties in storing milk for more than a few hours. Before this development, milk could be kept fresh for only a short while and was available only in the immediate vicinity of a lactating cow. While returning from a trip to England in 1851, Borden was devastated by the deaths of several children, apparently from poor milk obtained from shipboard cows. With less than a year of schooling and following a series of failures, both of his own and of others, Borden was inspired by the vacuum pan he had seen being used by Shakers to condense fruit juice and managed to reduce milk without scorching or curdling it. Even then his first two factories failed and only the third, built with new partner Jeremiah Milbank in Wassaic, New York, produced a usable milk derivative that was long-lasting and needed no refrigeration.