No need to add any alcohol to this, as this concoction will certainly make
it's own, and the alcohol you add will probably kill the natural yeast.
Each month the supply of fruit will fully ferment to an alcohol level high
enough to kill the yeast, about 10%. Then, when you add the next batch of
fruit, the process will start all over again. Yeast occurs naturally on
the skin of most fruits, but to be sure, add a few grapes with each new
addition. That whitish blush you see on the skins of grapes is yeast, so
do not wash the fruit any more then a quick rinse.
Sheldon ( and no fair sipping a sneak, hic! )