Go from VM to pot still

[scootr14]

I built a 2" copper VM hybrid. By hybrid I mean that I can break it down from 40" of packed/unpacked column, down to 20" of packed/unpacked column for pot still applications. I've been running running Rad's all bran with a 40" reflux with great success, but now I want to do a sweet feed run in pot still mode at 20", and I've evidently read to much so I've gotten myself confused. I understand to remove the packing, and make sure that my gate valve is open, but my question is, is it better to leave my double helix condenser in top and run it along with the liebig, or is it better to remove it and place a 2" cap ontop and run it only with the liebig condenser. I remember seeing someones set up like mine, but I can't seem to find it anymore. Thanks for all the great info on this site.

[myles]

For pot still mode there is no need to remove the packing at all. Use the bottom half if you wish but just add a cap to replace the column top half and connect to your liebig. I am assuming that you have a coupling of some sort between the two column sections.

If you use only the top half with the valve, you still need to cap off where your helix condenser sits. As you need to build a cap anyway, you might as well do it to fit on top of the bottom half of the column so you don't need to mess about with your reflux condenser.

Without induced reflux your packing rapidly heats up and behaves as though it is not there.

[scootr14]

Ok, thanks Myles. Not removing the packing is gonna save alot of time. I was thinking that I needed to remove the helix and replace it with a cap, but went brain dead after reading up on the Boka columns, slant plates, cm's, flutes, etc.

[scootr14]

And yes I have a set of ferrules welded between the columns so dropping it down to 20" wont be a problem. I've read that you lose flavor with the taller column, so I may try it both at 40" packed and at 20" packed and see which flavor profile suits me.

[myles]

It is actually a lot safer to remove the top section of the column and fit a cap to the bottom half instead to connect to your liebig. Do NOT fit a valve between the new cap and the liebig. If there is no valve present then you can't leave it shut by mistake.

Whilst you can make pot stills with valves, it is something you should only ever do if you absolutely MUST do so. In general it is a bad idea. Leaving a valve shut by mistake can seriously ruin your day.

As for flavour, on the pot still I just don't believe it. That vertical riser makes no difference - irrespective of how tall it is. A vertical 2" tube heats up surprisingly fast when the vapour starts to flow. Make it any height you like for convenience. The product end of the condenser needs to be at a suitable height for ease of collection.