Be part of our community & join our international next generation forum now!
I'm running a 15 gallon BH boiler, the top section of the 3" PSII column (two rolls of copper mesh) and 3 SD bubble plates. I use 1/2" needle valves to control the cooling water and a controller firing a 240V 5500 watt element. The wash was about 6-1/2 gallons of diluted low wines (very clear and at 40 abv) from a couple of stripping runs off of a sugar wash made with spent grains from several batches of NCHooch's AG bourbon recipe. This was only my second run with the plates so I'm still getting used to them.
I started up using the full 5500 watts and started dropping back as the plates loaded. By the time the top plated was loaded I was at about 1800 watts with the reflux valve half open. I was taking a very very slow drip of fores and after 30 minutes I started closing the reflux valve a bumping the heat up a little at a time until I had about 200 ml. I bumped up the heat a little more (2000 watts) and slowed the reflux valve until the reflux discharge temp was fairly warm.
Starting with jar 1 (250 ml per jar) and continuing thru jar 12, the distillate temp stayed cool and was very clear. The top of the column temp stayed between 174 and 175 (3" dial therm) and plates were active with clear sight glasses. Takeoff rate was 250ml every 8 minutes. Everything was running on autopilot until I was about 100ml into jar 13. The takeoff rate dropped to about half of what it had been and after a few minutes started surging to double the original rate. Slow for 15 seconds or so then surging for a few seconds. The distillate turned cloudy with a brown tint. There was also fine brown particles building in the funnels coffee filter. I let this go on a lot longer than I should have but kept hoping it would level out. During jar 20 I dropped the heat down and opened up the reflux coolant. I ran this way for about 15 minutes trying to figure out what to do next. Plate levels stayed about the same, full and active but not flooding over into the downcomer.
I shut the reflux coolant off and bumped the heat back up to 2000 watts. Takeoff rate was about the same as it was before, distillate was clear again with no particles in the filter. The parrot was still showing 178 proof and it didn't smell like deep tails. I shut if off at jar 28.
I tasted the cloudy distillate and it wasn't bad. In fact, I didn't really taste tails until close to the end of the run. I kept jar 4 thru 12 for hearts and ended up with 5 quarts of clean tasting 120 proof. Jars 13 thru 20 can't be used because of the clouding but have just a hint of tails. I plan on revisiting 21 thru 28 before dumping them back in the pot even though I know they contain tails.
Any help on understanding what happened to cause the upset would certainly be appreciated.