It has been traditional for churches to use, not unfermented grape juice, but de-alcoholised wine (i.e. it was wine, but they got rid of the alcohol). In my experience, grape juice is a more recent idea. We use grape juice at our church and I go along with that because, although I think the early church used wine and that some of the symbolism is lost with grape juice, the scripture only specifies 'fruit of the vine'. I have been to a couple of Anglican churches when away on holiday, where a choice was offered. Anglicans go to the front for communion, and those with medical or conscientiouis reasons for wanting non-alcohol were directed to the appropriate line. I thought that was good. In that case I joined the main, real-wine line.
I have had communion with elderberry wine, and though I know you good folk think our sacrament doesn't work anyway (no priests etc), can you think of any reason not to use elderberry, in a country where grapes do not grow but elder is abundant? It is a deep red, and an excellent accompaniment to a real meal, as the early communion services were.