Methods of Manufacture of Fermented Dairy Products

The use of fermented milks dates back to many centuries, although there is no precise record of the date when they were first made. The milk, which could not be preserved overnight in a tropical environment, led the Aryans to benefit with the phenomenon of fermentation. Having known the nutritional and therapeutic benefits, the Aryans have embraced dahi as a natural healthful delicacy of their diet. Ancient Vedic literature contains numerous references related to dahi, which shows its importance in the Indian diet right from the Vedic era.

Initially the souring of milk was done by natural fermentation. With the advent of science of bacteriology and nutrition, fermentation process emerged as a welldeveloped controlled sequence of changes in milk with the use of selective microorganisms. Selective organism produces lactic acid and may impart other beneficial effect to the product. The use of different microorganisms led the development of a wide range of milk products viz. dahi, yoghurt, shrikhand, lassi, kefir, koumiss, yakult, laben, etc. In India, dahi is being produced with varieties of taste varying with region-to-region and individual food habits. The consumption  statistics shows that about 6.9 per cent of total milk produced in India is utilized for making dahi intended for direct composition. In this chapter various types of dahi fermented milk products and their methods of manufacture will be discussed.