Originally Posted by: bigwheel I asked this over on the HD forum and some smart feller say he would answer but I had to start a new thread and I could not think of a good spiel so figger I just ask over here since yall are a lot smarter than them anyway. Heck I think yall are them come to think on it:) I know my BH HC has to reflux for a bit. Anybody know the scoop on exactly how long? And what I am also seeking is the right temp. I picked 165 for some reason and been trying to let it flounder around for thirty mins or so. Now the other smart feller implied there were sensory clues other than temp which could be indicators of when the reflux was adequate. Kindly tell me what you know. Thanks.
Well the whole point of a Reflux still is to produce clean neutral alcohol.
Lets talk about the type we both run, a packed column. While you are in complete reflux the vapors in the column rise, condense and fall back down through the packing towards the boiler. As this happens the rising vapors traveling up from the boiler through the column get "Scrubbed" as the pass the falling condensed vapor. When the condensed vapor reaches the bottom it starts all over again refluxing through the column.
The temperature of the vapor at the top of the column determines what constituents will be concentrated at that point in the column. This is why it is important to know a few of the boiling points of the different constituents within the Wash/Mash. Mainly the "Fore Shots & Heads" because this is what you are trying to concentrate for removal at the start of your run.
Here are a few important boiling points to keep in mind:
Acetone 133.7 ºF
Methanol 148.46 ºF
Ethyl acetate 170.78 ºF
Ethyl alcohol (95%), the azeotrope 172.58 ºF
Ethyl alcohol (100%) 173.12 ºF
With this in mind I would suggest you raise your holding temperature to 170 ºF.
As for the sensory clues, Fores & Heads are very concentrated & obvious when running a reflux rig. It will smell like finger nail polish remover, which is Acetone.
As for the length of time you hold her in full reflux.... well the longer you hold her the more concentrated the fores & heads will be when you remove them. Most don't exceed an hour.
Hope this helped you out & hope it didn't come across too "upidy"