how much juice instead of concentrate?

[Two_Sheds]

So, my recipe says one can (250ml) of grape concentrate, but I don't have it.

I do have one litre of grape juice.

Is that about right? My brain is fried.

Most grape concentrates are made by boiling grape juice at reduced pressure to eliminate about 75-80% of the water

[SarzWix]

Should be about right, as long as you elimainate 750ml of water from the recipe