DISCUSSION Alcohol Distillation How to Distill Spirits at Home
In this DISCUSSION Alcohol Distillation How to Distill Spirits at Home users exchange experiences on the distillation of alcohol, stills construction, mash preparation, alcoholic fermentation, diluting alcohol, and other related topics. In short: how to make alcohol at home.
Methanol derives from woody parts of the mash. So when you make a mash from marc (the residue of filterpressing grapes for making wine), the mash and also the distillate will contain a relatively high amount of methanol, because of the lots of pits. You can test this very easily: compare a very cheap grappa with an expensive one. The cheap one has a high amount of Methanol, therefore it will taste much hotter than the expensive one.
For instance avoid apples with a high amount of pectine.
Methanol has a lower boiling point (65 deg C) than ethanol (78 deg c), and it therefore comes out of the still as "heads".
Just discard the first part of the distillate (that will smell like nail polish), or wait until the temprature is > 75 deg C, and Bob's you're uncle!
If you try to achieve separation through distillation, both alcohols will evaporate at the same temperature, meaning you won't get any separation. The same effect occurs with a certain volumetric mixture of alcohol and water, which prevents you from getting 99.9% pure alcohol through distillation.
Also, methanol doesn't really smell like nail-polish in my opinion; I believe you're confusing it with acetone on that point.
Chris Barsby, “ Methanol Brochure” Alberta
Gas Chemicals Ltd. Technical memo
No.850220, March 7, 1985
You must be the only and unique one on the earth!
Tell us the secret, please...
It is, with usualal stills, IMPOSSIBLE to completely eliminate methanol from your destillate. To avoid methanol, produce ethanol from a mash containing sugar, no fruits! All fruit spirits like Williams etc. contain methanol, up to 5%... Nobody dies from it, just a hanghover if you drink too much of that stuff.
if i understand this properly, and we assume our what your distilling is a mixture of some percentage of methanol, some percentage ethanol and some percentage water (and some random shit)
this shows that methanol forms no azeotrope with either water or ethanol, suggesting it should come off the heads of the distilate, however ethanol and water do form an azeotrope at 95.5% so that the best your going to do with a stil..
also as a little parity:
specifically lists water and methanol as "non-azeotrope", as they are a firm specializing in solvent recovery (in this case recovery methanol from water) i would suspect they would say something about loss here.
not a professional, just geeky
if you have a reflux column and you drive it gently, with well controlled top temperature (i have counter current cooling in mine to nail it to the spot), then you should get all (or beyond measurement of what's left, anyway) the meths off by holding the top just above the boiling point of meths.
the water/ethanol (the azeotrope limited mixture) that is left will be held further down the column.
you'd also get a bunch of esters and acetones and other lighter and yuckky things coming off. bring the temperature too high and you'll lose the volatiles that define the flavour (for whiskeys, rums and other such things).
if you have a column like mine then you'll notice temperature fluctuations increase as you run out of the lighter fractions.
npo matter how good the column, unless you play with pressures too, you'll never get over the azeotrope minima at 94ish percent for ethyl alcohol.