Another great misconception, or set of them. The truth is that the first drop out of a potstill has exactly the same compounds in it as the last drop out of the still; only the relative concentrations of these compounds will change continuously throughout the still run. That means that if there is methanol in your wash (more about that later) there will be methanol in every drop out of that still run. The methanol will never "all be gone".
In spite of that, there's good news on a couple of fronts. First, most washes don't have any methanol in them to start with. Methanol typically comes from fermenting fruit with pectin in it. Raspberries and apples are some of the worst offenders. Looking at methanol contents of legal commercial spirits, Calvados, French apple brandy, has the highest methanol concentration I've seen. Even then, it has less methanol than nature's finest fresh-squeezed orange juice. Yup, Minute Maid has methanol, but in tiny (and completely safe) amounts.
Good news but not quite true: Even if you start with a tiny bit of apple or raspberry methanol in your wash, it was commonly held (until recently) that the rate of methanol evaporation is greater than the rate of ethanol and water evaporation, so that first little bit out of the still would have more methanol (and ethyl acetate and acetone, which taste bad and give you the bad head in the morning, while methanol has virtually no taste in ethanol), and you would be happier discarding that first bit. Because much of the methanol was thought to be in that first bit, there would be much less in the rest of your run.
In reality, and supported by recent analyses, methanol molecules form a loose bond with ethanol molecules, and it turns out that any trace of methanol in your wash is more or less distributed with ethanol throughout the still run. On one level, we've always known that; the reason the feds denatured ethanol with methanol was becuse the two are so hard to separate by distillation.
But (I can hear you say) "How come methanol has such a scary name?" During American Prohibition, there was so much money to be made selling illegal booze, that unscrupulous bootleggers "extended" their ethanol-based spirits by tipping the f*cking methanol can into the f*cking booze, and people went blind and died. Because this frightened people (still does 80 years later, surprisingly), it played right into the hands of government agencies enforcing prohibition, so that the methanol story was blown hugely out of proportion.
The upshot of all this is: if you don't want methanol poisoning from your booze, don't tip hte f*cking methanol can into your f*cking booze. Just don't worry about methanol, but don't drink theforshots and heads if you don't like the taste of acetaldehyde, ethyl acetate, acetone, and the rest of the headscomponents that taste bad.
Zymurgy Bob, a simple potstiller Making Fine Spirits
--- In firstname.lastname@example.org, "hverdag12" wrote:
> Hi everyone!
> This is my first post here, and the question might be a bit stupid, I hope you will forgive me:)
> Here goes:
> When distilling from a wine or mash base I've learned that the tail/head must be removed to avoid Methanol poisoning.
> Is this the same if re-destilling already pure alcohol?
> The reason I'm asking is that I am going to make a spice-liquor, where I will use a pure alcohol like vodka or brandy to macerate herbs in, and THEN distil it for a clean result (like Absinthe for excample).
> My guess is I won't have to worry about heads or tails as the alcohol is already methanol-free, but I want to be sure.
> Anyone who can help me answer this?
> Any help us greatly appreciated:)