I'm in Northern California - Sierra Foothills.

I agree about Cox' book - it is excellent, and I also recommend it. I'm
not trying to say it is flawed - just that there are a lot of variables
that go into how much wine one can get from any number of vines . Like
I said, there is so much variation depending on variety, spacing,
pruning, and location. In my vineyard, the Cabernet are very small
berries and relatively small clusters. Maybe 7 pounds of fruit per
vine, and maybe 6.5 gallons of finished wine per 100 pounds of fruit.
The Syrah on the other hand are larger berries and more productive ...
about 10 pounds per vine, and easily 7.5 gallons per 100 pounds of
fruit.

And while I get less wine per pound in general from white grapes,
because of the difference in efficiency of pressing fermented versus
non-fermented fruit, my Marsanne are the most productive grapevines.
Medium large berries, and bloody huge, dense clusters. Some of the
vines are probably producing 12 to 15 pounds per vine.



On 2008-02-01 13:15:41 -0800, "Paul E. Lehmann" said:


Axis, where do you live? The reason I ask is
because where I live (in the Northern Virginia -
Central Maryland area) I have always averaged 8
gallons of wine per 100 pounds of fruit and this
is from Merlot, Cabernet Sauvignon and Cabernet
Franc (12.5 pounds to make a gallon of wine).
The Cabernet Sauvignon is just slightly less than
this but not much (because of smaller berries and
thicker skin).

I also worked at a commercial winery in Northern
Virginia for a couple years after I retired and
the ratio of 8 gallons per 100 pounds held true
there also - of course we dealt with tons of
fruit but the ratio was still the same.

If you are basing your numbers on a hotter climate
region, then I can understand your results being
lower because of less juice - higher sugar ratios
and perhaps slightly raisoned fruit.

Even though Cox's book is not the "bible" on
viticulture or winemaking, it is a book I highly
recommend because it explains the basics in terms
all can understand and I have not found any
serious flaws.