Process — How hard cheese is made from milk

The diagram shows the eight stages in the manufacture of hard cheese from fresh milk.

Overall, the essence of the process is separation: the milk is deliberately set into a solid, the solid curds are divided from the liquid whey, and everything that follows — pressing, salting and ripening — concentrates and matures those curds. The time involved also lengthens dramatically at each stage, ending with months of ripening.

Fresh milk is first delivered and quality-tested. It is then warmed in a vat to about 32 degrees, at which point starter bacteria are stirred in. Next, rennet is added, causing the milk to set like soft jelly. In the fourth stage this set milk is cut into small pieces — the curds — while the liquid whey is drained off.

The curds are then stirred, gently heated and salted, before being packed into moulds and pressed for twenty-four hours into solid wheels. Each wheel is soaked briefly in brine, which begins to form the rind, and finally the cheeses are laid on shelves to ripen for anywhere between three and eighteen months, after which they are ready to be sold.