Cheese sampling. Workers check the quality of Edam cheeses as they mature. Cheese is made of the solid part of milk (curd). After separation from the liquid part of milk (whey) it is strained, moulded and left to mature. The maturing cheese is kept at carefully-controlled temperatures and humidity for a length of time. During this time, bacteria within the cheese ferment it, giving the cheese its own characteristic flavour and aroma.