Blaand has been a traditional drink made by farmers for their own use in Scotland, Iceland, the Faroes, and Norway for centuries. It was never commercialized; production ended in the mid-20th century. In these areas it was the most common daily drink before the introduction of modern drinks like tea and coffee.[1][2]
Blaand could be made by diluting the whey with water first and then letting it sour.[3][4]
Another approach was to put the whey into great vats, where it was left to sour; before drinking, some of the soured whey was mixed with water to reduce the acidity. The Norwegian name, "blande," simply means "mix,"[5] and the Scots word can mean the same.[3]
