Originally Posted by bartons15
How many cans would you need for a 5 gallon batch and do you add water? If not, wouldn't the concentrate be too sweet? Anyone ever do it this way and how did it turn out?
Just reconstitute the cans and use like normal juice. You'd have to check the gravity but I'd guess it would come out close to standard apple juice (Mott's bottled apple juice is 1.05, for reference). So the easiest thing to do would be to make 5 gallons of reconstituted juice and just pitch your yeast into it.
As to whether you should add some extra cans of undiluted concentrate (or add additional sugar) before fermentation to pump up the ABV, that just depends on how strong you want your cider to be. The only cider I've made I intentionally stopped fermentation before it was complete, but if you let it go all the way I've read it will reach an FG near 1.00, which would give you an ABV of 6.7% assuming you started at 1.05. If you want more alcohol than that, add more concentrate (undiluted) or sugar up front. If you're trying to approximate commerical hard ciders available in the USA, I think you'd want 5% - 6% ABV.
If you're planning to add concentrate (undiluted) or sugar for sweetness after fermentation is complete, just remember that will cause additional fermentation, leading to more alcohol and carbonation and less sweetness, unless you take steps to prevent fermentation (refrigeration, kegging + refrigeration, bottle pasteurizing). Just something to be aware of given the risk of bottle bombs. Because I wanted to make semi-sweet, carbonated ciders and was nervous about bottle pasteurizing, I waited until I got a kegging setup to make my first cider.