Camels' milk, women's milk and cows' milk were kept at 30 degrees C and refrigerated at 4 degrees C. This explains the necessity to immediately freeze milk if it needs to be kept even for a few days. Cows' milk remained good for days if stirred and then turned sour, enabling the making of cheeses and butter. Camels' milk did not sour at 4 degrees C for up to 3 months. This means that camels' milk is mainly good only for drinking, as was promised to this animal by the Prophet.