Well I've just strained my blackberry and apple off the blackberry pulp and got it into fermenters - it's basically a 1 gallon recipe, but as I had 9 litres of apple juice and 3lb of frozen blackberries, I got 2 x 1 gallon's and about 1 1/2 pints of must left over.
The extra bit is in the fridge so it might tighten up the bottle a bit (a plastic bottle) while the ferment dies down, but that shouldn't be a problem. Once the ferment has finished it can be topped off - the yeast in the spare bit will have settled on the side of the bottle anyway.
Oh and despite the recipe saying that it needed 680g of sugar, I've said bollocks and used a whole kilo - yes it will probably still ferment it ok and it will make it a bit stronger, but I'm not fussed about that as I'll be ageing it for 12 months plus so that should sort out any "alcohol hotness" type taste that might be apparent.
I've also got the plum started fermenting on the pulp - it will have to be strained after about 4 days, onto the sugar, though that recipe does say 1 kg of it. So I'll sort that on Thursday evening.