For over 25 years Miltonduff Distillery produced 2 different Single Malt Whiskies. In 1955 due to the increased demand within Hiram Walker for different styles of whisky, a chemical engineer, Alistair Cunningham designed the Lomond Still. This type of still had a wide neck which housed three rectifying plates. These plates were used to vary the amount of reflux that took place within the still thus altering the spirit produced.
The plates could either be filled with cool liquid or left dry. They could be rotated - the horizontal position would maximise reflux while the vertical position would reduce reflux. Due to increased demand for Ballantines Blend in the 1980s, the Mosstowie stills were altered to produce Miltonduff - the key component of Ballantines.