I know that most people use two cans per gallon, rather than
reconstituting the juice according to the directions, in making wine
from Welch's frozen concentrate. They do this because Concord
grapes are too acidic, or so I thought. Jack Keller's recipe calls for
2 tsp of acid blend, though, and that makes me wonder if
reconstituted juice, sugar to 12% PA, and no acid would make a
better wine. This is what I have in mind ...

Ingredients:

4 cans Welch's (or other 100% concord) frozen concentrate
water to reconstitute (12 11.5 oz cans would be 1 gallon plus 10 oz)
sugar to 12% PA (a pound?)
sulphite (1 campden tablet or equivalent)
1 tsp peptic enzyme

Procedu

bring water to a boil, then remove from heat
dissolve sugar and cool (I usually immerse the pot in cold water)
stir in concentrate and pour into fermenter
add sulphite and enzyme, then pitch yeast

Notes:

This works out to more than a gallon, but I think that's a plus in that
there's less topping up. In fact I often make "1-gallon" batches with
1.5 gallons of must (a "vintner's gallon?") to avoid topping up with a
different wine. Nutrient might be helpful, but I think it's unnecessary in
grape juice. Until I heard that people were adding acid to the 2-can
recipe, I would have made the above recipe with 2 cans.

I'm planning on making a wine from frozen concentrate, maybe one
batch with 4 cans and another with 2 cans. I know some people are
making these kinds of wines; what is your experience? Does 2 cans
plus acid result in a balanced wine? Ever try it without additional acid?
How about 4 cans? Crushed and pressed Concord grapes?

Erroll