"pp" > wrote in message
om...
> "Lum" > wrote in message
>...
> > Ray & Andy,
> >
> > One mole of sugar produces 2 moles of alcohol. The molecular weight of
> > sugar is 180 and the molecular weight of ethanol is 46. So
theoretically,
> > 180 grams of sugar can produce 92 grams of alcohol. 92 divided by 180
is
> > .511 or 51.1 percent.
> >
> > But in practical fermentations, only 90 - 92 percent of the sugar
produces
> > ethanol. The rest of the sugar produces higher alcohols, acetaldehyde,
> > succinic acid, etc.
> >
> > In addition, some alcohol is blown off by the escaping carbon dioxide
gas.
> >
> > See Margalit, "Concepts in Wine Chemistry," page 56.
> >
> > Regards,
> > lum
>
> Ar a recent talk, a professional winemaker here from BC mentioned that
> they were getting higher alcohol levels for the starting Brix than
> they used to, often by 1% or even more. She said this was confirmed by
> other winemakers from the area. Her hypothesis was that the yeast were
> getting more efficient in alcohol production. This could have large
> repercussions if that were indeed the case. I'm wondering if this is
> happening in other, hotter areas, as well?
>
> Pp
> Vancouver, Canada

Some types of wine yeast produce more alcohol than others, so the above
situation certainly seems possible. But, I don't understand what the "large
repercussions" would be.
Lum
Del Mar, California, USA