The first advances made in distillation technology
Although the distillation technology is known since the Ancient Egypt for the production of perfumes, it seems the technique used before the 11th century was not able to produce alcohol, suitable to be drunk as the cooling system at the output of the still did not enable to collect of a sufficient quantity of liquid.
The first production of uisge beataseems to date back to the 15th century in monasteries. Uisge beata was used as a medicine as well as for direct consumption. (see poem of Raphael Holinshed).
The first significant enhancements in distillation technology date back to the 16th century, when the air cooling system was replaced by a tube crossing a tub filled up with water. This tube was first placed straight in the centre of a tub, and later diagonally in this tub, which increased the surface of the tube being in contact with fresh water. The tube should later adopt the shape of a serpentine, allowing an optimal cooling by increasing the surface to be in contact with the water again.
Another enhancement in the same period has been the lengthening of the lyne arm and the changes in its shape, to get the current onion shape. The result of this shape changes was that a greater part of the evaporated liquids fall back in the still, ensuring a better suppression of impurities in the final liquid.
Both enhancements resulted in a serious improvement of the quality of the produced alcohol, and marked the real beginning of the economic expansion of Scotch whisky.