We have a 1000L Kothe still we just hooked up. A local brewery gave us a wash and we ran our first ever batch through the still. We're still learning our equipment and I wanted to reach out to the forum to get some help with some of the issues we're having.
1) Dephlegmator - When the guys from Koval came to set up the still, they said we wanted to run our dephlegmator at around 77C. This has proven very difficult. The dephlegmator is cooled by the water that exits the condenser - the condenser temp is controlled by a thermostatic valve on the ingoing cooling water. As the distillation progresses, the temp of the dephlegmator will increase and the ABV in the parrot will drop significantly (seemingly way before it was supposed to). We had to then increase our cooling to compensate, long story short the temp and our ABV ended up being all over the place for most of the distillation. Has anyone else run into this? Since other factors play a role in the dephlegmator temp (vapor temp, volume of vapor) do you think it would be a good idea to get the dephlegmator on it's own, separate control system that can self regulate the temp of the dephlegmator itself? Also, is it a good thing that the dephlegmator temp increases as the distillation continues? Will this allow for compounds with a lower vapor pressure and higher BP which could add valuable flavor components to make it through into the tail end of the hearts?
2) The plates - What effect have you all found in terms of adjusting the liquid level in the plates? I have in my notes from when the Koval guys came here is that having the plates more closed (high liquid level) gives higher separation (cleaner distillate) that having them all the way down. Is this because it forces all of the steam to condense when it hits that plate? Wouldn't having the plates more open force more liquid to drain back into the previous plates and into the still and also have a purifying effect? What effect to do see in ABV off the parrot with the plates? Effect on the flavor? Difference in upper plates vs lower plates? Any recommended ways to run it?
Thanks everyone, hopefully I can repay the favor with some needed info for you one day!
You should see the defleg temp rise over the course of the distillation. And yes, the abv will diminish as will the volume. Do a complete set of several runs and see where your cuts will be; heads and tails. That 77c setting is variable; you can go higher for lower proof, or lower for higher proof. But again, it will slide higher during the course of a run. for us that slide is maybe 5 degrees f.
This is just us, different users have different experiences that take them to different places.
I run with the condenser and dephlegmator on two different water lines.
I've never used a dephlegmator so this is purely a question: I thought the purpose of a dephleg was to compress the cuts? I've read where people have ran it hard in the beginning and then scaled it back to produce a lot of reflux for the "heads" portion. I'm completely unaware of how this works in practice though - seeing as I don't have one.