From The Food Encyclopedia by Jacques Rolland and Carol Sherman
Milk with additional milk solids added, heated to above regular pasteurization temperatures, then cooled to 108°F (42°C), to which bacterial cultures are then added and left to incubate for four to six hours. Armenian immigrants Rose and Sarkis Colombosian produced the first commercial American yogurt in 1929 and began selling throughout New England in 1940, while Daniel Carasso, whose father founded Danone (named after Daniel) in Spain in 1919, founded Dannon Milk Products in New York in 1942. Danone first put fruit in yogurt in 1947 for novelty and to balance its sourness, to which the market wasn't yet accustomed.
