Dick Adams wrote:
> What are the determining factors for the quality of the resultant
> brandy?
>
> Do you have any idea of the expected efficiency conversion factor?
>
> Are there specific styles of wine that are better for making brandy?

Well with brandy, you will distill out the acids and more volitile
compounds like methanol and ethyl acetate (that is why you can make it
from pomace, something that when fermented would leave a lot of
methanol, treating vegetable material with pectinase releases
methanol).

So really wines that are not of good of a quality can make fine
brandies, wines with either very low acidity that would not age well
are traditionally distilled into brandy, and wines that have
excessively high acidity can also be made into brandy.

What you do want is a very defined fusel alcohol character. Because
brandy is usually distilled once, a lot of the fusel character will
remain in the spirit. Now the exact fusel character that is needed is
really only known to a master distiller. What I do know is the wine
quality does not necessarily mean high quality brandy (and vice versa).