Westerham Audit Ale. The Black Eagle Brewery in Westerham brewed Audit Ale throughout the early 20th Century. Its fame was such that it was supplied to Clarence House for the beginning of the oyster season. This Audit Ale is brewed to the same strength and uses the same ingredients as that brewed in 1938. We also use the same yeast as used in Westerham Ales up until the brewery’s closure in 1965.