Blue Stilton's distinctive blue veins are created by piercing the crust of the cheese with stainless steel needles, allowing air into the core. The manufacturing and ripening process takes nine to twelve weeks. For cheese to use the name "Stilton", it must be made in one of the three
counties of
Derbyshire,
Leicestershire and
Nottinghamshire and use
pasteurised local milk. Manufacturers of Stilton in these counties received
protection under European Law as a
protected designation of origin (PDO) in 1996. The cheese remains protected by its PDO even after
Brexit, under EU law (in the EU and Northern Ireland) and under UK law (England, Scotland and Wales). By September 2016, just six
dairies were licensed to make Stilton – three in Leicestershire, two in Nottinghamshire, and one in Derbyshire – each being subject to regular audit by an independent inspection agency accredited to European Standard EN 45011. Four of the licensed dairies are based in the
Vale of Belvoir, which straddles the Nottinghamshire/Leicestershire/Lincolnshire borders. This area is commonly seen as the heartland of Stilton production, with dairies located in the town of
Melton Mowbray and the villages of
Colston Bassett,
Cropwell Bishop,
Long Clawson and
Saxelbye. Another Leicestershire dairy was in the grounds of
Quenby Hall near the village of
Hungarton, outside the generally accepted boundaries of the Vale of Belvoir. Quenby Hall restarted Stilton production in a new dairy in August 2005 (the old dairy dated back to the 18th century) but the business folded in 2011. Stilton cheese has been made in Derbyshire since 1900, originally at
Hartington. The former Dairy Crest-owned licensed dairy that produced the product at Hartington was acquired by the Long Clawson dairy in 2008 and closed in 2009, with its production transferred to Leicestershire. Two former employees set up the Hartington Creamery at
Pikehall in Hartington parish, which was licensed in 2014. Three additional partners soon joined them and this business is the smallest of the six companies licensed to make Stilton. As of March 2021, Hartington Stilton was marketing within the UK but also exporting to the US and to the EU; it had just started exporting to Canada. The company director told the BBC that they had "a surge in interest and consumer sales from the US" but it had to stop sales to the European Union following
Brexit because of the cost of a veterinary surgeon certificate. Stilton cheese cannot be made in Stilton village, which gave the cheese its name, because it is not in any of the three permitted counties, but rather in the administrative county of
Cambridgeshire and the historic county of
Huntingdonshire. The Original Cheese Company applied to Defra to amend the Stilton PDO to include the village, but the application was rejected in 2013. Stilton cheese was also manufactured in
Staffordshire. The Nuttall family of
Beeby, Leicestershire opened a Stilton cheese factory in
Uttoxeter in 1892 to take advantage of the local milk and good transport links. However, this firm did not last long and the site became a general dairy. ==Protected characteristics==