How do people die from methanol poisoning?
It starts with an unlabeled drink or a bottle that has been refilled. This is endemic in many parts of the world. In this case it was a town popular with hikers in Viet Nam.
The alcohol comes from a local illegal still, what we call "Moonshine". Fruits or grains are fermented to make a kind of beer or wine that is distilled into harder alcohol. There is always some methanol in fruit that we eat, beer or wine which we drink, as a natural ...
@BrucePerens_K6BP your explanation, while correct, may have given the bad folks the benefit of the doubt.
Methanol, aka wood alcohol, is easily produced by passing steam through wood shavings.
Cheaper to make than moonshine, it can be used to 'cut' it, to borrow a drug trade term. Common during prohibition, I understand.
https://www.medlink.com/articles/methanol-poisoning
Makes interesting reading
@G8GDS - Yes, it is possible that methanol was deliberately added. It's also possible that a distiller used pomace, skins, peels: fruit by-products which are high in pectin, which converts to methanol and requires additional attention to the "cuts", the portion that you discard from the still. These are popular with moonshiners because as a waste product, they are cheap or free. A skilled distiller can make grappa from them, an unskilled one can kill someone.
@BrucePerens_K6BP in my short career as an illicit distiller I would ditch everything except the ethanol-water azeotrope at 78.2° C. Working in a university I was lucky enough to have access to a well instrumented 10l lab glass still with a 1 metre column. A gas chromatograph provided QA.
There were homemade wine makers among my colleagues and the feedstock was the occasional below-par batch of wine.
A second, fast, distillation with botanicals yielded a passable gin - OK in cocktails.
@G8GDS - That's the right way to do it. I think I was touring Indigeny Reserve, a cider maker and sometime brandy distiller in Northern California. There was a 55 gallon drum of methanol on hand for cleaning, and to show folks how much they've extracted.