[WaterFarmFan]

Originally Posted by G.O. Joe

Does pot dry alcohol or does alcohol dry pot?

Hey Joe. I would say that alcohol drys out pot. "Hygroscopy... is achieved through either absorption or adsorption with the absorbing or adsorbing substance becoming physically changed somewhat... as water molecules can become suspended between the substance's molecules in the process."

Originally Posted by G.O. Joe

What does cold boiling mean? If it's vacuum then you'd have to look up the vapor composition for that vacuum. Or vaporizing below boiling should obviously favor removing the alcohol.

I think that I phrased it poorly. I was asking if the water content in 190 proof acts independently of the alcohol when under vacuum distillation. I do not want to separate water from alcohol, just trying to understand why some but not all of the water evaporates from my concentrate solution prior to purge. I use a mantle and glassware (@ ~200 micron) to vacuum distill down to a thin syrup consistency.

[WaterFarmFan]

I think what I am asking about is the chemical attraction of water to alcohol under different conditions. If you boil 190 ethanol on a hot plate, does water & alcohol evaporate at the same ratio throughout the process? Is this different under vacuum?

[zif]

~190 proof is the azeotrope, so yes, alcohol and water will boil off in that ratio. It looks like vacuum breaks the azeotrope. You can pull nearly pure ethanol around 100 mm Hg @ 33° C. So at that point you’d leave all of the water in your extract.

Looks best to start with dry solvent and material....

[WaterFarmFan]

Originally Posted by zif

~190 proof is the azeotrope, so yes, alcohol and water will boil off in that ratio. It looks like vacuum breaks the azeotrope. You can pull nearly pure ethanol around 100 mm Hg @ 33° C. So at that point you’d leave all of the water in your extract.

Looks best to start with dry solvent and material....

Do you think that the concentrate ratio to alcohol/water can break the azeotrope? I have decarbed (190 alcohol) extract in a double boiler and watched temps with a thermocouple. It first rises to 190s F and then rapidly to low 210s F as it works through the boiling points. It will then shoot up, but I have removed at this stage and the extract is still a bit runny at room temp, which to me indicated there was still some water content, even after going over the boiling point. Just trying to square my observations with some hard science. Thanks!

[troutman]

Originally Posted by WaterFarmFan

Do you think that the concentrate ratio to alcohol/water can break the azeotrope?

NO.

Also just because your Cannabis feels dry doesn't mean there's no water in it.

If it was 100% dry it would probably crumble to dust.

[zif]

^ This is almost certainly practically the case.

Azeotropes are tricky and may depend on the other compounds (e.g., terpenes). I suppose adding more dry alcohol should allow you to drive water down to any arbitrary level, though, by taking advantage of the azeotrope?

Take that with a grain of salt because although I like the theory, I haven't distilled spirits for a decade or more. And then it was for the spirits!

[WaterFarmFan]

Thanks for the info. I use cured flowers that have ~10-15% moisture, but I freeze flowers to -70C and soak with -50C ethanol. I might get a bit of condensation during my vacuum filtering. Do alcohol and water maintain the azeotrope at different proof levels below 190? So, if 95% alcohol picks up a bit of water, which I assumed was the case every time that you reclaim and then reuse alcohol, and becomes 94%, does it behave differently?

[troutman]

More water = More chlorophyll pickup.

[WaterFarmFan]

Originally Posted by troutman

More water = More chlorophyll pickup.

I totally get that, and it is why I take significant steps to keep temps in -50C range during extraction, but I am talking about tiny amount of residual water in concentrate after purge. After I started freezing flowers to -70C prior to extraction, I do not see one slight hint of green in my post-filtered solution, and this includes both 190 and 200.

I ran out of 200 proof and have used quite a few gallons of Everclear. Everclear extracts are a bit less stable at room temp vs 200, and I was just guessing that it was water content from the 190. Any other ideas? Thanks.