Dunlop Cheddar is a cheddar cheese that is made from raw milk from Ayrshire cows.
It is usually sold young, before it has fully ripened, when it is semi-firm and mild and creamy. It was meant to be a hard cheese with a stronger flavour, which requires 6 to 12 months of aging, during which it is frequently turned, but producers like to sell it while it is young because as it ages, it loses weight.
Though named after Dunlop, East Ayrshire, Scotland, the cheese is now mostly made on the Arran and Islay islands.
In March 2011, an Ayrshire maker of the cheese applied for European Protected Geographical Indication (PGI) status for the name “Traditional Ayrshire Dunlop.” The applicant was Ann Dorward of “Dunlop Dairy” in Stewarton, Ayrshire, who was also at the time the only remaining maker of the cheese actually in Ayrshire. 
The specifications suggested are that the cheese be sold as a harder cheddar, aged between 6 and 12 months, with an average of 10 to 12 months. They also suggest that Ayrshire cow milk is essential, because its smaller fat globules allow the butterfat to more easily be incorporated into the cheese’s curd. The milk used would have to come from the local area, either from the same farm where the cheese is made, or sourced from other farmers in the local area.
A starter culture, rennet and sea salt are added to the milk. These don’t have to be obtained locally.
Dunlop Cheddar was invented by a Barbara Gilmour in Dunlop, Ayrshire, Scotland in 1688.
She was a “Covenanter.” Convenanters were people in Scotland who disagreed with the English attempt to impose a system of bishops on the Scottish Presbyterian church. They got caught up in the battles between the English Parliament under Cromwell, and the English kings. They were outraged when first the English Parliament and then Charles II signed a covenant to support the Scottish Presbyterian system as it was, but then disregarded their promises when Scottish support was no longer needed.
She along with others were forced to flee for their lives to Ireland. There, she lived in County Down, and learned how to make cheese to earn a living.
She returned to Scotland after the Revolution of 1688, and brought her techniques back with her. One of her ideas was to make cheddar from whole milk, which was an innovative idea at the time in Scotland. Dunlop Cheddar was called “Sweet Milk Cheese”, which meant cheese from unskimmed milk. Her methods were widely copied by the end of the 1700s.
There are some doubts about her ideas and the Irish connection: whether she picked up her ideas while in Ireland, or whether she picked them up from someone else in Scotland. In any event, she at least popularized her methods.
Gilmour intended her Dunlop Cheddar to be a hard cheese with a strong flavour.
 “The applicant company is the only company producing ‘Traditional Ayrshire Dunlop’ cheese in the defined area. However, the applicant recognises that any producer in the defined area has the right to produce the product in accordance with the specifications and the obligations imposed by the regulatory framework.” — Ewan Scott. Application to Register the name ‘Traditional Ayrshire Dunlop’ as a Protected Geographical Indication (PGI) under the EU Protected Food Name Scheme. A Consultation Paper. Food and Drink Industry Division of the Food and Drink Industry Division, Government of Scotland. March 2011.
BBC. Bid for EU protection for Orkney and Ayrshire cheese. 20 March 2011. Retrieved June 2011 from http://www.bbc.co.uk/news/uk-scotland-12795541
Trupp, Nicky. Cheese firms in bid to protect names. London: The Independent. 21 March 2011.
Scott, Ewan. Application to Register the name ‘Traditional Ayrshire Dunlop’ as a Protected Geographical Indication (PGI) under the EU Protected Food Name Scheme. A Consultation Paper. Food and Drink Industry Division of the Food and Drink Industry Division, Government of Scotland. March 2011.