Depending on how the wash is turned in the still, different chemicals (aldehydes, esters, higher alcohols, and a number of other substances in very small amounts) are evaporated.

After the first wash, there is still 6–7% solids from the barley in the wash.[9] During the heating process, kinetic energy increases (molecules move faster) until they start to change phases.

In the cooling pipe, kinetic energy and entropy both decrease resulting in another phase change from gas to liquid.

[3] Single pot still whiskey emerged as a means of avoiding a tax introduced in 1785 on the use of malted barley.

Although this tax was repealed in 1855,[11] the popularity of the style endured until the emergence of blends in the late 19th and early 20th centuries.

By 1980, only two specialist bottlings remained in existence, Green Spot and Redbreast, with one in danger of being discontinued.