"Bob" > wrote in message
hlink.net...
>
> "Ben Rotter" > wrote in message
> om...
> > "ed montforts" > wrote in message
> > > sorry, but you are some way off. It's NOT the pectic enzyme that
causes
> the
> > > trouble. The pectin itself is. The pectic enzyme breaks down pectin,
> that is
> > > the source of methanol. So if you use pectic enzyme in juice that
> containes
> > > pectin, you can get rid of almost all methanolproduction, provided you
> toss
> >
> > Actually, I think *that's* the wrong way round.
> >
> > Methanol results from the hydrolysis of pectin by pectin
> > methylesterase enzymes (PME). It's the action of the PME which
> > produces the methanol. Since PME is one of the enzymes typically used
> > in most commercial pectic enzyme preparations, use of most pectic
> > enzymes will result in increased methanol production.
> >
> > This increase, however, is usually low (at least in grape wines) and
> > most of the methanol resulting from it is reputed to be lost with CO2
> > during fermentation.
> Methanol boils at 148*F, 30* below ethanol. I suspect it shouldn't be
> much of a problem with most wines; to be honest, this is the first I've
read
> of methanol being involved in the fermentation process.
> Anyone have any figures on % of methanol in =any= known wines?
> Bob

In "Concepts in Wine Chemistry," Margalit indicates that wines can contain
"from 40 to several hundred milligrams per liter" of methanol.
Lum
Del Mar, California, USA