"Matt Lyndon" > wrote in message
...
> Hi all,
>
> Just made my first batch of wine. Can somebody please offer some advice.
If
> I know the starting gravity (1080) and I know the final gravity (992) what
> is the equation to work out the percentage alcohol. I read somewhere that
> you divide by a certain figure. Can anyone help. I am making Beaverdale
Red
> Rioja.
>
> Many thanks
>
> Matt
>

Hi Matt, Louise, Robert, et al.

You can not have more alcohol in the wine than your original PA predicts.
Both my hydrometer and chart indicate this is ~10.6%ABV.

If a wine finishes dry, there is *no need* for an end alcohol calculation
since the original PA already tells you how much alcohol is in that wine.

If a wine "sticks" and the maker decides to "restart" and force it to go
dry,
then the same thing applies. Since it ends up dry, the original PA tells
you
how much alcohol is present.

Only if a ferment ends with residual sugar present is there a need for end
alcohol and residual sugar calculations since part of the sugar is _not_
consumed and thus converted to alcohol. In this case the alcohol will be
_less_ than the original PA predicted.

Keep in mind that _part_ of the total SG drop is caused by the effects of
the alcohol on our _end_SG reading, so _total_drop cannot be used to
make such calculations. Only the amount of drop caused by the consumption
of fermentables (sugars) can be used to estimate end alcohol. HTMS

Frederick