If I was to do some distillation of lets say "plum water suger" then I would use a homemade still with a thermometer (where the vapor reaches the condenser or in the liquid to be distilled?) so as to get a more precise distillation. discarding the first 50 ml sounds a bit hit or miss to me.
so one would have to get the liquid up to the point at which the methanol boils (or acetone etc even though thats the first time Ive heard that, it sounds like you know your stuff) and no higher, untill no methanol comeout anymore, and discard? then bring up to ethanol boiling point and keep everything that comes out? maybe repeat the process a couple of times to purify further?
So even with a still with a thermometer, I wouldnt be able to separate methanol from ethanol? or just not to complete purity of the ethanol?
This seems confusing, and still cant see why distilling a bottle of wine would do you harm seeing as your only taking stuff away(H20), theres no chemical reaction happening.