Fresh, local milk is poured into an open vat. Essential ingredients are added at this stage – acid forming bacteria known as starter cultures, a milk-clotting agent such as rennet and penicillium roqueforti – which is the blue mould spores, essential to give the cheese its famous veining. Now the curds begin to form, whey is removed the the curds are left to drain overnight.
The curds are divided and transferred into the Stilton hoops or moulds. They are then left to drain for several days at a set temperature and humidity. The hoops of Stilton are turned regularly to allow an even distribution of moisture to spread through the cheese.
The milling process breaks the curds down into small pieces, which form the basis of the cheese
The cheesemaker uses a knife to smooth of the edges of the roundel, preventing blue mould growth at this point.
After five or six days, the hoops are removed and each cheese roundel is sealed by smoothing or wrapping, to keep air out. The cheesemaker uses a knife to smooth of the edges of the roundel, preventing blue mould growth at this point.
The cheeses are now moved to a store, which is carefully controlled for both temperature and humidity. During this ‘ripening’ period, the cheese continues to be turned regularly, for about five weeks.
Once the five weeks are up, the roundels are pierced with stainless steel needles to enable the blue mould to develop and give the cheese its characteristic ‘veiny’ appearance. Piercing is repeated a week later, before each cheese is individually graded.
After about nine weeks, the cheese is ready to be sold. But first it must be graded. A cheese grader is a highly skilled expert, often with years of experience in assessing the quality of cheese. Using a cheese iron, they take a core from the roundel of Stilton, and based on its smell, taste, appearance and texture, decide if it can be sold as Stilton, or just ‘blue cheese’.