But wine ain't beer and the more water you add the more you dilute the flavor of the fruit. Sometimes diluting the fruit can make sense - as when the fruit you want to ferment is very acidic , although there are other (better ?) methods of neutralizing acid... but simply to add water to strawberries or blackberries rather than reduce the volume of the wine you are making may not result in a flavor-rich drink. One test I use is to taste the diluted juice before you add any sugar to see if you would find the flavor too thin. If it's to thin before it ferments it won't be any richer after all the sugars have been fermented out... In my opinion, it takes about 10 lbs of strawberries to produce a gallon of wine...