I remember the story of missionaries in the Amazon jungle who did communion with Coca-Cola and potato chips, because that was all they had. Just my opinion, but under the circumstances I think it was valid. The substances were wrong, but their hearts were right with God, doing the best they could with what they had.
But, hey, what do I know? I'm a former Pentecostal and still new to the apostolic/liturgical way of doing things.
Seriously, I do believe real wine is the proper/best thing to use. But there are people who aren't allowed to have it for medical reasons, or because they're recovering alcoholics afraid that it might cause a relapse. And also there are those with a personal conviction against consuming alcohol. I disagree with that, but I can respect it. I think in any of those circumstances it's best to settle for what you can have, rather than forgo it entirely. Possibly non-alcoholic wine might be an acceptable compromise? Though I've never had that and don't know if any of it is any good.
Now, if you'll excuse me, I think I'll pour myself a nice glass of cabernet.