How to install a Thermometer in a Moonshine Still

The number one question we get asked VIA email and over the phone is this: "How do you add a thermometer to the still and where is the best place to install it?" When making moonshine it isn't critical, or even absolutely necessary to measure temperature, but there are a few benefits. A thermometer can be used to help detect the presense of methanol in moonshine and can also be used to determine when to shut down the still at the end of a run

Here are the 3 best options for installing a thermometer in your moonshine still. Please note, we don't stock this equipment, but we've found the highest quality equipment for the most reasonable price and have provided links below.

GOOD Option: Measure Vapor Temp With a Digital Thermometer

moonshine still thermometerThis is by far the easiest method of installing a thermometer in a moonshine still. Measure vapor temperature by Installing a small digital thermometer in the column, or install one in the cap plate next to the column.  Drill a hole through the copper just barely big enough for the thermometer.  Don't try to solder it.  All you'll do is destroy the thermometer.  Just install the thermometer after the still gets warmed up at the beginning of a run and seal it with flour paste. 

BETTER Option: Measure Liquid Temp With a Weld-less Thermometer

The second (better) option would be to purchase a stainless steel weldless thermometer kit and a stainless steel thermometer with a 1/2" NPT connection Install it in the boiler wall to measure liquid temperature drilling or cutting a hole in the boiler wall just big enough for the threaded end of thermometer (as shown in the video above) and install it using a weldless thermometer kit. Make sure to use high temperature, chemical resistant teflon tape when assembling. 
 
Buy all of these for the second option:
 
    stainless steel thermometer 1/2 NPT fitting for distilling and brewing    
 

BEST Option: Measure Liquid Temp VIA a Permanent Copper Fitting

The absolute best way to add a thermometer to your copper moonshine still is to permanently install a 1/2" copper bung and then screw a stainless steel thermometer with 1/2" NPT threads into that. Solder the copper fitting into the boiler (as shown in video above). Apply teflon tape to threads on thermometer and screw thermometer into copper fitting. Hand tighten and then snug with pliers. Do not over tighten.
 
Buy all of these for the third option:
 
copper 1/2 inch NPT fitting for distilling and brewing thermometer    stainless steel thermometer 1/2 NPT fitting for distilling and brewing    
 

Top Secret Pro Tip: Use a Stepped Drill Bit For Boiler Wall Hole

After we created and published our thermometer video someone emailed us and mentioned that we should use a stepped bit to make the hole for the thermometer in the still boiler wall. If there is a right tool for this job, the stepped drill bit is it! We managed to get by with our tin snips, but it's not the easiest thing to do and also doesn't produce a very clean opening. Stepped bits are self piloting and they make a super clean hole in the copper. We definitely picked one up for the shop after seeing how awesome they are.
stepped drill bit