America has been experiencing a huge surge in the popularity of craft and small-batch spirits coinciding with the craft beer boom. According to the American Craft Spirits Association, there are about 770 craft distilleries in the United States. That might not sound like many, but consider that only a decade ago there were only around 50!
This growth in the number of distilleries brings with it a surge in the need for distilling equipment. This includes still tanks, and more – like temperature and level sensors to ensure efficiency, accuracy, and safety in the distillation process.
The Distillation Process
The distillation process works due to the low boiling point of pure alcohol. In basic terms, the mixture to be distilled is heated, and as the alcohol evaporates the vapor is cooled, condensed, and allowed to drip into a separate container. The condensed liquid takes on some of the characteristics of the surrounding liquid, giving different liquors like whiskey, tequila, and others their distinctive flavors and characteristics.
With pot still distillation, a batch of fermented liquid (usually made from a fermented grain like corn, barley, or rye) is placed into a large copper pot which is then sealed and capped. The pot is heated up to the point where the alcohol boils, but not the surrounding liquid. As the alcohol vapor rises, it is drawn into a coil submerged in water, which then cools the vapor back into liquid and drips it into a collection vessel. While pot still distillation has existed for centuries and is capable only of producing small batches, column stills were invented in Europe in the 19th Century and are capable of producing much higher volumes. Simply speaking, column stills consist of numerous pot stills stacked on top of one another, separated by perforated plate partitions. The still is heated from the bottom while fermented mash is added to the top. Cooler material settles downward as heated material from the bottom rises to the top.
As the heated material rises, it is filtered by the partitions, resulting in a purer ethanol alcohol product.
Custom Temperature Sensors Are Ideal For The Distillation Process
The most important sensor required for the distillation process is an accurate temperature sensor, due to the need for striking a perfect balance between boiling off alcohol and leaving the surrounding material in liquid form. SMD Fluid Controls’ FT20 custom temperature switch is an example of an efficient, accurate temperature sensor.
Vertical or horizontal float switches can be used for low-level or high-level alarms and emergency shut-off to prevent equipment failures or accidents.
SMD Fluid Controls also offers custom or off-the-shelf combination temperature and level sensors to combine both functions into a single convenient unit. The FM22 for example works in temperatures up to 250º C, making it well-suited to still applications.