How much sugar per gallon of crushed grape juice is the rule of thumb? I fermented my crushed muscadine grapes for 9 days in a bucket. Strained the juice out of the pulp and seeds and put in 5 gallon carboy. Had about 3 gallons of juice and I added 1 gallon of distilled water. Added 10 lbs of sugar and a pack of yeast. So I added 10 lbs of sugar to 4 gallons of liquid. Is that enough??