I’d be interested too. I did a small experiement on my euro-30. What I’ve done so far is to put a 1-wire thermometer into the fitting for a regular themometer in top of of the still and measure what is going on. Reading from a regular thermometer was always a bit difficult. I was going to move onto other matters once I had done some measuring.
In my case, it was very interesting to see the temperature slowly moving up for a period and then suddenly shoot up to a very level 79 before remaining very steady. This was with constant water flow. No fiddling needed with the water flow at all and I was getting around 93% alchohol. Towards the end, the temperature started to rise slighty, and my still is designed to essentially stop prooducing when getting to the end point of the run. The element simply doesn’t have enough power, by design, to push any more energy in for the temperature to continue rising.
So I decided my old, simple still balanced very easily and I didn’t really need to do any more.
I did try a test run with just water, setting up a brewpi fridge and the temperature to 77 and that worked fine with the element comming on as needed. The system reacted quite quickly to changing the fridge temperature, faster than I expected.
I probably don’t need to, but for the next run, I was going to try controlling the heating and keeping the temperature to 77 rather than the natural 79 using the brewpi. In my case I cannot increase the water flow any more from the design of the still.
I don’t see why you could do much the same with your rather larger setup. I’m not sure if it’s possible to drive each of the heaters seperately, but it would be neat to drive both up to the point of getting a good initially flow and then cutting back for the main run.
My cooling flow is very simply, but if you have a mains pump that would accept the controlling influence of the brewpi, that would make sense.
I’d be interested in seeing anything you come up with!