Single grain is a grain whisky produced by one grain distillery. The name of the distillery features on the label, such as: Invergordon, Cambus, Strathclyde, Cameron Bridge. At the heart of a controversy that lasted more than 20 years, the single grain whisky produced by the Cambus distillery (closed in 1992) was the subject of a huge advertising campaign in 1906.
Since then, single grains have only been bottled very rarely. Over 99% of production is absorbed by producers of blended whiskies. However, one producer, Compass Box, offers a bottling that incorporates some very old stock from the Cambus distillery: Hedonism.