Making wine from store brought juice

[Tommcd]

Hi guys was wondering if anyone could help.
Been looking and seen one I want to try,
1ltr red grape juice
2ltr apple juice
900g of sugar
Cup of tea
Obviously thats only
going to be just over 3ltrs so would you add the rest water when adding sugar, or liittle water with sugar and top after first few days of fermenting. If so top up with water or juice. And how would this affect your original gravity reading?

 

[Rice_Guy]

A quick Sugar calculation:
270 gm one L grape juice
225 gm two L apple juice
,,0 gm one C tea
600 gm sugar
1.095 total sugar

at 11% alcohol you can make 4600 grams of must (primary)
at 13% alcohol you can make 3700 grams (about a gallon Primary)

This reads as if it was designed to be a little over 4100 gm primary, then rack into a 4 liter glass followed by racking into a 3.79 liter (gallon)

 

[Tommcd]

OK perfect I think I understand how that works with adding the sugars like that now.
But if I was to add say a ltr to make it easy of water to top it up how would that affect it By reducing the gravity for adding that 1ltr

 

[Rice_Guy]

I would add water for the purpose of topping off the carboy once it has the air lock on it.
I would hate to put the batch together, rack and then say OOPS what should I do with this extra 400 ml of wine?