Historically, most cheeses were seasonal, only produced at certain times of year, often to suit the conditions of the milk. At the end of summer, drier grass caused the cattle to produce richer milk. This milk was ill-suited to making harder cheeses, so – much like the Comte makers in France, who would turn to making Vacherin – the cheesemakers would switch from hard, crumbly cheeses to softer, veined cheeses, ideally suited to the richer milk. Even now, Stilton is still at it’s best at this time of year, when it becomes richer and developes a smoother, more rounded flavour, thanks to that late summer milk.
By the early 18th century, the blue cheese had been discovered by Cooper Thornhill – an innkeeper of the Bell Inn in Cambridgeshire – and was being marketed year round and was finally given the name we know it by today, named for the town which the Bell Inn served. There’s some dispute as to whether a similar cheese was historically made in the town, but today, it can only be made in Nottinghamshire, Leicestershire and Derbyshire if it’s to carry the protected name.