how is curd formed?

Curd itself is considered a dairy product. It is obtained by curdling (coagulating) milk with rennet or an edible acidic substance such as lemon juice or vinegar and then draining off the liquid portion (called whey).

Curd is made from nonfat milk and is either plain-cured or plain-cured with cream. Its texture is always soft with curds of varying size. Because of its high water content, curd will last only until the expiration date on the container unless it is stored in the container upside down.

Curds are a dairy product made by the introduction of acidic substances like lemon juice in milk. The acidic substances cause the milk to ferment resulting in the separation of milk protein (casein) which forms in lumps while the liquid content known as whey is drained off. The curdling agent used widely in the manufacture of curds or yogurt as they are known when produced commercially is rennet an enzyme obtained from cattle.

Curds retain the same amount of fats and vitamins present in the milk from which they were prepared but contain significantly less amounts of lactose which makes them an ideal dairy product for lactose intolerant people.

In some cases curd is consumed along with the whey by whipping the mixture to form buttermilk which is a drink much valued for its beneficial effects. Curd when subjected to pressure resulting in the removal of the water content results in the formation of various cheeses like cottage cheese and paneer. In Asia curd is prepared by the addition of yeast as a fermenting agent. The time taken for milk to curdle depends on the climate with the process taking about 6 hours in summer and up to 16 hours in winter.

you can make emmy tasting yogurt just like in india using fat free milk only.
heat 1qt. fat free milk in microwave for twenty minutes on high heat.
let it cool down to 110 degrees f.
remove creemy layer on the top and add a 1/4 tsp culture.
for culture use either yogurt or butter milk.
if its creamy first time try again. guaranteed success.
keep the vessal in a hot pack if possible.
in 5 to 6 hours you will have great tasting yogurt.