Question

why warm milk take more time to become curd in winter season as compared to summer seasons

Answer 1

Due to the presence of bacteria called Lactobacillus milk is transformed to curd. These bacteria only become active at medium temperature like 30 – 40⁰C. In winter the temperature of everything including milk also decreases rapidly. Even if the milk is heated, it reduces temperature very fast due to cool environment. Thus bacteria cannot grow properly in the milk due to very low temperature. If bacteria cannot grow, milk will also fail to produce curd in winter.