"donny" > wrote in message
...
> Wine grapes ( grapes period), make there own yeast for
fermentation,,,,,com.
> yeast only speeds up the process and costs you more....Grampa is
> right....Such is experience in your trade ....

That's inaccurate. Grapes do not "make" yeast. The waxy white coating on
the grape skin (called the bloom) causes airborne yeasts to adhere to the
grapes. When the grapes are crushed the yeasts come in contact with the
juice, which renders them active, resulting in fermentation.

If you're lucky, the fruit will have "caught" a friendly strain of yeast and
the wine will turn out OK. If not there may be a serious problem with
excess production of volatile acidity by competing spoilage organisms.

Sounds like grampa has been lucky.

Tom S