"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