Butterfat: the particles of fat in milk.

Casein: the protein in milk which forms curds when coagulated with rennet.

Cheddaring: the process of stacking and pressing slabs of curd (coagulated milk) together, over and over, until most of the whey (watery liquid) is drained from the slab. The cheesemaker always does this by hand.

Cheese: a food made from milk that has been coagulated, drained and molded. The word we use is derived from its Latin name, Caseus.

Coagulation: the curdling, or bunching together of the casein in the milk after rennet is added.

Curds: the clumps of casein formed when milk is coagulated.

Hoops: forms used for pressing the curds into shape after salting and before ageing.

Lactic acid: the bacteria that sours milk. It is naturally present in milk.

Lactose: the sugar found in milk. During ageing the lactose turns into lactic acid.

Pasteurizing: the process of heating milk to destroy harmful bacteria.

Rennet: the mixture containing the enzyme rennin used to start the coagulating process. Rennin is found in the gastric juices of animals and is also produced in the laboratory. Grafton uses microbial, or non-animal rennin, approved for vegetarians.

Whey: the water left over from the drained curds after the milk is coagulated. The drained whey is often recycled for use as fertilizer.