yogurt

Semisolid curdlike dairy product made from milk fermented with bacteria. It was originally made by nomadic tribes of Central Asia, from mare's milk in leather pouches attached to their saddles. It is drunk plain throughout the Asian and Mediterranean region, to which it spread, but honey, sugar, and fruit were added in Europe and the USA, and the product was made solid and creamy, to be eaten by spoon.

Heat-treated, homogenized milk is inoculated with a culture of Streptococcus lactis and Lactobacillus bulgaricus in equal amounts, which change the lactose in the milk to lactic acid. Acetaldehyde gives yogurt its characteristic flavour. Commercially, fruit, flavourings, and colouring and thickening agents are added to the fermented yogurt.