why curd forms faster in summer than winter
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.
So, due to cooler temperature which is less favourable for bacteria, curd takes longer to settle in winters.