Caerphilly is a hard, white cheese that originates in the area around the town of Caerphilly in Wales, although it is now also made in England, particularly in the South West and on the English border with Wales. It was not originally made in Caerphilly, but was sold at the market there, hence taking the town's name.
Caerphilly is a light-coloured (almost white), crumbly cheese made from cow's milk, and generally has a fat content of around 48%. It has a mild taste, with its most noticeable feature being a not unpleasant slightly sour tang.
It is rumoured that the cheese was developed over time to provide the coal miners of the area with a convenient way of replenishing the salt lost through hard work over ten hour shifts underground and so was a staple of the diet of the coal-miners.
Real Farmhouse Caerphilly production died out during World War II as all milk had to go to the Cheddar factories to help the war effort. After the war these factories started making their version of Caerphilly (initially to help their cash flow as Caerphilly matures quicker than Cheddar), which is how it is mostly known today, dry and crumbly. However, there are now two or three farms making original Caerphilly which is dry in the middle and creamy around the edges.
The town of Caerphilly holds a three day festival annually to celebrate the cheese entitled The Big Cheese (Welsh: Y Caws Mawr). Also in Caerphilly, there is a sculpture of a cheese.