What is the sg of the juice?
Correct me if I am wrong, but if you want .70gpl TA and there are 3.79 liters to the gallon, then wouldn't you want to add 2.653 grams per gallon?
I will first have to find grape juice. Here, we usually get fruit drinks - juice in water with sugar added. We do get imported juices but not all flavours are always readily available. Furthermore, I may not find the same brand I used to make this wine. We do get orange and apple juice consistently as these are locally packaged.
Have been thinking, what other fruits go well with red grapes? We will soon have plums and apricots will start soon. Mangoes have started coming in. Papaya, peaches, melons, water melons and cantaloupes are already available. Strawberry is gone now, and so are raspberries and mulberries. Lychees should be available soon and grapes won't start coming in till end of June. Bananas and tinned pineapple is available year round.