The process of yoghurt making is an ancient craft. It combines both art and science together. The microorganisms and their enzymes i.e. the yoghurt starter culture play an important role during the production of yoghurt. The transformation in the image of yoghurt from strictly a health food to one that has been promoted as fun to eat dessert with various flavours and aroma additives has been a phenomenal one. Milk should have a low bacterial count and substances, which may impede the development of yoghurt culture.

Yoghurt is one of the most popular fermented dairy products all over the world. The production of yoghurt has shown tremendous increase during the past few years mainly due to the introduction of wide variety of flavours and or fruits to the yoghurt.

Different forms of yoghurt are now available in the market like stirred, set, frozen and liquid yoghurt. The flavour of yoghurt irrespective of the type is the same since the main flavour compound is acetaldehyde.

According to FAO / WHO code and principles the minimum SNF of milk should be 8.2 percent. However, the fat content in yoghurt may vary from 0.5 to 5% and the total solids from 9 to 20%.

An increase in the total solids content, particularly the proportion of casein and whey protein results in a firmer yoghurt coagulum and the tendency to whey separation is reduced. Stabilizers may be used for increasing the viscosity and prevention of whey separation in fruit yoghurt. The amount of stabilizer varies with the type of stabilizer. The stability and the consistency of the yoghurt are improved by the homogenization of milk.

The firmness of the gel improves with the increasing homogenization pressure. Sweeteners in the form of sucrose or glucose can be added to the fruit yoghurt. The fruit contains about 50% sugar and normally makes up the entire sugar content. Small quantities of sweeteners can also be added in the production of natural yoghurt.

Method of manufacture of yoghurt