Temperature control is important when distilling.
Don't lie down on the job.
Distilling alcohol at home is an exciting process that requires skill and diligence. If you want to be great at it, be aware of some important considerations about temperature. Distillation requires a lot of heat, and it’s important to control that heat, so you distill safely and end up with a high quality product (called the “distillate”).
Several factors go into producing a high quality distillate - your mash recipe, the mash’s ABV, and your still are a few important ones - but every experienced distiller knows that temperature control is key to making a fine alcohol when it’s all said and done.
Distilling alcohol uses high temperatures - generally around 200 degrees Fahrenheit. High temperatures mean opportunities for accidents, so make sure that everyone who is in your distilling environment is aware of how hot your equipment will get. Controlling and monitoring the temperature will help you keep your distillery safe.
The temperature of your still varies in different spots. There are three key places on your still where you should monitor the temperature - the pot boiler, the top of the column, and the condenser coil.
The temperature inside the pot boiler will tell you about the boiling liquid in the mash. Keep it increasing, maintaining a range of 175 - 195 degrees Fahrenheit for as long as possible. Turn off the heat when it reaches 212 degrees Fahrenheit.
The temperature at the top of the column will tell you about your alcohol vapor as it begins to condense. Monitor this temperature, watching for an excess of 180 degrees Fahrenheit. If it becomes overheated, turn down your heat.
It is especially important to use a built-in thermometer
at the top of the column in a large column still
Keep an eye on the touch-temperature of your condenser coil. The coil should be kept cool to the touch, with cold running water or ice packs. If it reaches room temperature, decrease the heat on your still and pack more ice on the coil. If the condenser coil ever becomes hot to the touch, end distilling immediately.
When all the elements of your temperature control come together, the condenser coil should release a steady drip of moonshine - not a stream, but a quick and regular amount that flows without interruption.
As you begin a run, your still’s seams will tighten as the metal naturally expands with the heat. Have your homemade flour paste ready, and you can easily seal the seams with it when the temperature reaches approximately 100 degrees Fahrenheit. If you wait too long to seal the still’s seams, the metal will burn both your fingers and the dough.
Different liquids boil at different temperatures: While the boiling point of pure ethanol is 174 degrees Fahrenheit, there are other trace elements that boil at slightly lower or higher temperatures. By controlling the temperature of your still, you can collect trace elements in different cuts in your run. Experienced distillers often make cuts - separating the distillate into portions - based on the temperature of the alcohol vapor.
Water boils at a higher temperature than alcohol, and as alcohol boils off from the pot, there is more water being boiled. So, the longer you run your still and the hotter it gets, the more water there will be boiling into steam at the later stages of your run. There is no reason to let the temperature climb higher than 212 degrees Fahrenheit, because that is the boiling point of water. Many distillers will cut off their run somewhere around 205 - 207 degrees, knowing that the last 10% or so of alcohol left in the mash won’t be worth it. Letting the still heat over 212 degrees is great if you’re looking to distill water, however.
You can assume that the longer you run your distillation around 175-195 degrees Fahrenheit, the more time you will be producing a large amount of high-quality distillate. With some variations and exceptions, this temperature range produces the purest ethanol and will typically be the “hearts” cut of your alcohol run.
Monitoring the temperature of your still, in addition to recording the mash recipe, type of still, a description of the distillate, and other details about the run, helps you repeat batches that were amazing, and avoid repeating mistakes in the future. Make the most, and the best, out of your moonshine still every time.
Article by: Jim Thomas
Photo credit: Eli Christman