Why is the first and last 5-10 mL of distilled Vodka poisonous?!
What is this compound, and why does it turn up in the first and last few mL's?
Answers: When using grain or potatoes to make vodka, the first few condensed mL's are discarded because they can cause blindness and other ailments.
What is this compound, and why does it turn up in the first and last few mL's?
That's the methanol you're talking about. It has a lower boiling point, so would be the first to leave. Shouldn't be in the tails, though - all the methanol should have left long before. I believe the last part is not used due to the flavors. Most of what I have read about home-distillation is to discard the first 50ml.
Still, I did find one site that disputed the reasoning behind doing that:
http://www.moonshine-still.com/page7.htm
Your friends were lying to you to get the last drink...
:)
Fusel oil mainly.
Get you to think that and you will stay out of my liquor cabinet!