So, a while back I posted some pictures of my new still set up, with a 15.5 gallon keg boiler and a 46-in cooling length, 3/4 inside 1" leibig condenser.

I was asked when I ran it, to comment on how my cooling system worked.

Instead of continually running water - I'm in California and we pay close attention to that stuff - I tried setting up a recirculating cooling system. Basically I have a 20 gallon reservoir, with a submerged pump pushing water through the condenser and into the top of a piece of 4-in ABS pipe. I currently have a 6 ft cooling length, filled with crumpled fiberglass window screen, at a 300 CFM fan blowing air up through the water dripping through the system.

If you look back through my profile, you can easily find my previous post, which has pictures of the system.

I've done some measurements and monitoring of it during cleaning runs, and now I've done some stripping runs as well, and here's what I've learned so far.

Stripping runs of a 10.5 gallon wash, yielding 2.4 gallons of 27 ABV low wines. Run over a gas burner, brought to a boil at full power, and then turned down to an output of about 8,200 BTU / hour, or 2400 watts. This is power actually being delivered to the wash in the still, calibrated by running it with pure water and measuring the volume boiled off and recondensed. At that power setting, it takes right at 2-1/2 hours for the stripping run.

My cooling reservoir starts right at 65° F. That temperature starts climbing pretty much immediately when I start getting distillate coming off the spout. At 1/2 hour 96°F. At 1 hour, 115. 1-1/2 hr, 125. 2 hr, 132. And then it stays at 132-133° F for the rest of the run.

These temperatures are measured at the surface of my cooling reservoir, and it occurs to me that there might be some stratification happening, and the temperatures down to the bottom where water reenters the tank and the circulating pump is, might be cooler than that. I'm reasonably certain that the low wines coming off the spout are not 130° F - they don't burn my finger - but I haven't measured that directly. I have another stripping run coming up late this week, and I'll update this report with some additional measurements on the temperature at the bottom of the reservoir, and try to get a good measurement of the distillate temperature at the spout

It looks really cool, with steam bouling off the top of the tower as it's running. It is very clearly stripping a substantial amount of heat and carrying it away.

This works, and I'm able to do the entire stripping run down to about 5-6 ABV off the spout, 27% ABV low wines.

That final equilibrium temperature in the low 130s is higher than I would like, ideally I'd like to keep it down around 120.

I probably won't get to it before my next stripping run, but hopefully before the run after that and my first spirit run, I'm going to try adding 4 ft to my tower, lengthen it to 10 ft cooling length with screen packing inside, and see what that does to my temperatures.

So at this point, the system works, but it's running very near the limits, and there's additional work to do. I'm hopeful that it's going to end up being a solid system with some modification.