Cloudy distillate for my first two runs

[BB48ss]

Hi All,
I have a homebuilt reflux still, 20 liter pot, 1500W hot plate, 1" copper column packed with SS scrubbers, and a separate condenser that returns the reflux to a point about 2/3 up the column. My first two runs were a basic sugar wash and I have had mixed success. I have two main issues:

1. On both runs I have blown out my flour paste seal on the pot. To finish the run I stacked some bricks on the pot but it still leaked a bit which did NOT make me happy. It seems that I'm building up some pressure in the pot which I assume is not right? Perhaps my column is packed too tightly? For the second run I throttled way back on the heat but still "blew a gasket" There is some backpressure when I try to blow through the packing so I'm going to pull it and repack with a bit less.

2. My distillate is coming out cloudy. I've read a lot about spirits clouding up when mixed for dilution but mine is cloudy right out of the still. I was able to get my reflux going and the spirits came out 90%+ so I know the still is doing its job but I can't figure out why it is not clear? The foreshots and heads came out pretty clear, then the first part of the hearts was very cloudy but by the end of the run it had cleared up a bit (not crystal clear though). Perhaps I am getting some foaming and carry-over? Is this related to my blown seal on the pot? I have noticed that during the warmup my temperature leaving the column overshot 78°C by quite a bit (then I blew my seal) before settling down to right around 78°C which leads me to believe I have some foaming or some other transient that is occuring during warmup and possibly contaminating the distillate....?

Any thoughts would be greatly appreciated....
-B

[LWTCS]

Kinda sounds like too much heat to me. Are you able to control your input?

[BB48ss]

I was able to reduce the heat for the second run, I'm using a hot plate but its a pretty good commercial model with variable control and a thick cast iron element so it does a pretty good job holding temperature. AFTER the temperature stabilized it definitely wasnt at a "rolling boil" it was more of a "simmer." I'm thinking I need to bring the column up to temperature VERY slowly to reduce the temperature/pressure spikes at the begining.....

-B

[rad14701]

BB48ss, pressure in your boiler = big problems... Don't run that still again... 1" copper simply isn't big enough for use as a reflux column, but it will work for a pot still... 1.25" is the smallest copper that can be successfully used for a reflux column, and only if you are careful... I run a 1.25" combo stove top rig and can't imagine going smaller... Several members have attempted 1" with similar results to yours... There's no need in going into details about the cloudy spirits because the small size is causing that as well...

You'll have far better results with 1.5" or 2" copper... It may be harder to source but well worth the effort and expense... The only reason I'm running 1.25" is because I got just enough to build my column for free...

Use the right tool for the job...

We have plenty of great information here so dig in...

[BB48ss]

Thanks for the info; I’m already looking into sources for some 2” copper. However, for my own information could you elaborate on what is causing the cloudy distillate? Is it foaming/carry over into the packing? Is it carryover all the way to the condenser? I like to understand why things happen…

[rad14701]

Thanks for the info; I’m already looking into sources for some 2” copper. However, for my own information could you elaborate on what is causing the cloudy distillate? Is it foaming/carry over into the packing? Is it carryover all the way to the condenser? I like to understand why things happen…

The pressure buildup, and subsequent release, is most likely causing some foaming and that is contaminating your structured packing... Pressure raises the boiling point and a de-pressurization will cause sudden energy release and foaming... Removing the packing and running as a pot still would probably eliminate the clouding problem...

[Dnderhead]

when you push your still to hard,all the vapor going up leaves no room to reflux.
(condensed vapor coming back down to be redistilled) so it just pushes all or most
out. if you have to use that column the Id suggest removing packing and use as a pot still.
this will leave more room.

[mann_ox]

any materials that arn't alcohol resistant ? .
And too much power ! hehe get a fan and blow air at the vessel if its getting too hot ( poor mans option )

[Dnderhead]

"hehe get a fan and blow air at the vessel if its getting too hot"
not necessarily work, a column has vapors rising,and returning
all in the same tube and at the same time.thank of a fountain
it sprays water into the air and then "rains "down, now if you placed a
pipe over this? if the pipe is large enough the pressur will push
the water up,then it will fall back and run out the bottom.
now if you use to small of pipe the water will go up and out the top
or have a blow out,this is similar to what is happening when flooding.
(this is simplified)

[LWTCS]

if ya blow enough cool air on the boiler no vapor will rise silly

Recon that might be so...

But that really is a waste of fuel IMO.....Unless I'm missing something.

Please continue with your assertion.

[mann_ox]

deleted the post cos i thought it was a waste of time and people don't need to hear about it

[grunthor777]

I have a 1.5" column, which works fine on the 12L stock pot I use. On stripping runs, everything hums along nicely with a minimal amount of effort, however, when i do a spirit run, I really run through my check list. 1) Packing nice and loose - packing means extra pressure I have never packed it "too tight" and would hate to see the results if i did. 2) extra seal clamps - even with loose packing I have had minor seal blow outs, so I pay extra attention to my seal, making sure its thoroughly dry, and adding extra clamps. IMO even 1.5" is too small for a reflux column, but is passable. mine produces beautiful neutral spirits, but takes a long time. I have some 3 inch stock that is waiting for an appropriate ss keg, can't wait to get that one off the ground and work the kinks out.