Cooling Tube @museum.de

M: The secret of distilling spirits lies ... any idea at the back there? In the cooling. Because the more effective the cooling, the higher the yield. That's why distillation equipment has been increasingly refined over time.

F: The cooling tube was extended – and then run through a barrel of water. Later, a second tube was added, doubling the cooling capacity.

M: The idea of using water for cooling probably arose around the year 1400. With this new system, it became possible to work more efficiently, distil larger quantities and produce higher-proof alcohol. The first distillation process resulted in what's known as crude distillate with about 20 per cent alcohol. That was then distilled a second time to produce the refined distillate in which the alcohol content could be increased to 50 per cent and more.

F: And another technical innovation was added. From now on, the still was heated indirectly. That reduced the risk of the mash becoming scorched. However, the cap still had to be removed for filling. These days, the caps are screwed on and the still is filled through a second opening. The cap serves an additional purpose: it prevents foaming mash from contaminating the distillate.