Add water to top up blackberry wine?

This is my first wine making expedition, and i started with about 15 lbs of blackberries and mixed up almost a 5 gallon batch. I let it sit for a week and tonight just transferred to a demijohn - i actually think my demijohn might be closer to 6 gallons in size, and because i left some of the wine (with the sediment) behind, i'm probably down to 4 gallons. Should i top up with water? If so, how much? I'm not sure i should add a whole gallon of water, won't that make the wine lose some of it's "body"?

By the way, it's still bubbling quite a bit, so also wondering if i racked it too soon...

These are the recipe steps I was following:

Sprinkle the wine yeast over the surface of the juice and then cover with a thin, clean towel. Allow this mixture (must) to ferment for 5 to 7 days. You should start to see some foaming activity within 24 hours of adding the wine yeast. Typically, 70% of the fermentation activity will occur during this 5 to 7 day period.

5. After 5 to 7 days remove the pulp from the fermenter and discard. Siphon the wine into a carboy in a careful manner, so as to leave the sediment behind. You can easily remove the pulp by lifting out the fermentation bag. Wring out any excess juice from the bag. Siphon the wine off the sediment without stirring it up. Get as much liquid as you can, even if some of the sediment comes with it. If necessary, add water back to 5 gallons

15 pounds of Blackberries is good for about 3-4 gallons of wine max.

I don't use the All fruit No water recipe's that some folks do. My last two batches of Blackberry wine were with 4 and 5 lbs of berries. They were great, however; any less than that is likely to give you a wine a bit on the weak side.

So my recommendation would be NOT to top off with anything, stay at 4 gallons - If you want a 100% blackberry wine. Otherwise you might find a commercial wine for topping off but frankly if you are down to 4 gallons I'd stay with that quantity. Using a commercial wine to get to 5 gallons is going to mean your wine will be 80 % blackberry 20% what ever wine you use.

Also you will like lose a little more volume on future rackings. I topped up my wines with water but normally not more than 1 to 1 1/2 cups total.

Hope that helps.

I wouldn't top up.With fruits I have been taught to use 7-10 lbs per gal(usually) so I think you're good as is.Can you find a 3 Gal carboy and a 1gal.? You could then use the 1 gal for top ups as the other clears.
What was you starting SG and SG when you racked?

I'll suggest a slightly different top off method. First it depends our your carboy / jug empty inventory. Find the closest empty ones, rack into it & then I top off a Cab. We like this so much that we usually now make a 80% Blackberry & 20% Cab blend. Don't top off with water, your wine will be way too weak. Roy ps if your racking into 2 carboys/jugs make one straight B B & the other a blend!