Alan Salt kindly gave ten members and friends a lively introduction to cheese making and its history in a guided tour of the factory. This was a fascinating morning.
Every farmhouse in the Peak District would have made its own cheese at one time and sold it at the local market. In this limestone area cellars would have been difficult to construct so cheeses were normally stored in lofts above the kitchen or dairy. These cheeses were white, relatively mild cheeses with a crumbly texture like Lancashire, Cheshire, Caerphilly or Derby (as opposed to the pressed, closed texture of a Cheddar). However, in Leicestershire such cheeses were kept in cellars which were cool, damp and often mouldy. It was in a vaulted cellar colonized by a blue green mould that the crumbly open texture of the cheeses was accidentally invaded by the Penicillium glaucum (synon. roquefortii). This accident proved to make the cheese rather tasty and thus a blue cheese was born.
It was via a family connection that the cheeses from this cellar happened to be sold at a busy coaching inn (still in existence) on the AI in the village of Stilton in the Melton Mowbray area of Leicestershire and finally became known as Stilton. The cheese became very popular. Daniel Defoe refers to Stilton in his writings.
In the 1870's the Duke of Devonshire had established a creamery at Hartington in Derbyshire. So in fact cheese has been produced there for 125 years and for the last 100 years it has been producing a fine Stilton. In the 1920's a far-sighted regulation - a certification trade mark confined the production of Blue Stilton to Leicestershire, Nottinghamshire and Derbyshire.
In the early days, the process of producing Stilton was as follows. Cheeses already infected with Penicillium glaucum were packed next to new cheeses so that the strain passed on to maintain the blue cheese. The mould broke down fat and protein in the cheese so that it matured more quickly and had a fuller flavour.
Following a fire at the end of the 19th century the factory closed for several years before being reinstated by Thomas Nuttall, a prizewinning cheese maker from Melton Mowbray. It subsequently gained the prestige of being the oldest remaining working factory in England.
John Nuttall followed in his fathers footsteps, making cheese on a commercial scale and held a warrant to supply Stilton to King George V.
There are now six factories producing Stilton cheese. Leicestershire has five. Hartington Creamery in Derbyshire accounts for 20% of the country's Stilton, as well as uniquely making Buxton and Dovedale Blue. Different strains of P. glaucum may now be used in cheese making but it is more often the texture of the cheese and the length of time it is allowed to mature that gives it a different flavour in the case of each variety.
After watching an excellent video we had to don small green hats and white coats which made us feel rather like an amusing little group of death caps! Then, following a hand wash and shoe bath, we were escorted around the factory. We saw the huge horizontal vats where fresh, previously cooled milk is piped in, warmed, and mixed with salt and rennet. Rennet is an enzyme made from another mould, Mucor pusillus, which coagulates the milk. We watched the vats being inspected by hand for coagulation and being stirred by hand with racks until precisely the right stage of liquid whey and lumpy curd was reached. It was then transferred to other vats where the whey slowly drained off. The correct temperature for these two processes to take place is vital and a good deal of equipment is required to maintain very accurate temperature control. A streptococcus bacteria is now added to change the lactose in the milk to lactic acid. The important P. glaucum is cultured elsewhere and supplied to the creamery later. We were not aware of exactly how and when this was inoculated into the cheese. That part of the craft the producer prefers to keep to himself.
The white fluffy curds are next packed lightly by machine into plastic cylinders called hoops. These are stacked on boards and turned regularly so that all the whey can drop out through either end or through perforations. The cylindrical cheese is then tipped out and bound by hand. Skilled ladies deftly run over the surface of the cheese with a knife. This process produces a crust which seals the whole cheese.
The cheeses are stored on impressively high racks in cool, humid conditions to mature. They are turned regularly, again by hand, and then pierced by stainless steel wires on a machine to ensure the aeration of the cheese which is conducive to the growth of P. glaucum. The fungus develops in the veins created and spreads throughout the cheese.
Because of the mould, Stilton matures more quickly than other, white cheeses, taking 3-4 months to reach its prime as opposed to 9 months - 2 years in the case of Cheddar for example. However, the process of turning the milk into cheese takes only four hours for the latter as opposed to a lengthy twenty four hours for the Stilton. This is because it is vitally important to get the texture of the Stilton correct for the mould growth.
Obviously Stilton cheese-making is still comparatively labour intensive but as Alan Salt pointed out - cheese is really just preserved milk - lasting longer than fresh milk and being easier to transport! The three basic preservation processes used in making cheese are 1) the removal of moisture 2) the addition of salt and 3)acidification. It takes 70 litres of milk to produce a traditional 161b Stilton.
Since 1974 the factory has been extensively redeveloped and is currently owned by Dairy Crest Limited, employing approximately 135 people who convert 70,000 litres of milk per day into cheese. Hartington cheeses are still winning prizes today at major cheese shows, with Hartington Stilton, Dovedale and smoked Stilton. The various grades, or flavours, of the cheeses depend on maturation time. After being packed at Hartington, they are sold at grocers and supermarkets.
When we had finished our guided tour, we were allowed to sample the mouth-watering variety of cheeses produced by the Creamery - Hartington Stilton; Dovedale Blue; White Stilton with Apricots and Wensleydale with Cranberries. All delicious. We sped round to the shop to choose with great difficulty from the tempting range of cheeses on offer all enriched by the activities of a little fungus.
Thank You, Alan Salt and Hartington Creamery for a most enjoyable and informative visit.