The steps of curd formation are:
i. The milk is boiled, and then it is cooled up to 70℃.
ii. In the warm milk, a spoonful of pre-made curd is added and stirred well.
iii. It is allowed to rest for a few hours. The bacteria in the pre-made curd starts breaking down the sugar molecules present in the milk. This causes the milk to curdle, thereby forming curd.
The microorganism involved in the formation of curd is Lactobacillus.