My Arduino-Equipped Still
By Jay Settle
AT CORSAIR ARTISAN DISTILLERY IN
Nashville, where I work, we came across a
1920s copper still that escaped Prohibition,
and we were dying to put it to good use.
Unfortunately, it was missing the crucial
piece that allows us to view temperature
readings, which reveal everything about the
distillation process from beginning to end.
When you want a monotonous task to just
work itself out, day after day, learn Arduino.
Recently, I had messed around with Arduino to
turn things on and off, and I knew I could wire
up a couple of temperature sensors and view
the still’s temperature on an LCD screen.
In addition, we’ve got a bit of a time pinch
when the liquid begins to foam — we have to
cut the heat within 10 seconds so it doesn’t
boil over into the batch. Foam-over in a still
run is catastrophic!
To prevent it, distillers either use a silicon
anti-foaming agent (yuck), or, like us, they use
their eyes to visually monitor it through a sight
glass and then adjust the heat accordingly.
During each distillation, we wait for the foam
to pass by the sight glass, and then cut the
heat to let the mash settle. After 5 minutes, we
turn the heat back on at a lower setting and let
it roll for the remainder of the distillation.
I found a photoresistor that could measure
light, wired it into the microcontroller, and
placed it over the sight glass. There’s a significant light shift when the light reflects off
the foam. I wired a 12V motor to the still to
control the heat, and a water on/off valve to
control water flow to the condenser. This way,
the Arduino could have a “digital eye” into the
sight glass, watching relentlessly for the foam
and controlling the heat accordingly.
I spent some time perfecting the code, and
now we pump in the liquid, flip a switch, and
walk away. The Arduino handles the rest. ;
Jay Settle’s passion for automation with Arduino is documented
176 Make: makezine.com/29