Hello, I've made country wines for years and am still alive, so here's a couple of hints. Has the bottle got a cork made of cork? Has it been stored horizontally? It is possible that the cork will have dried out if not stored horizontally, and the wine will have gone off. There may a sediment at the bottom of whatever way it was stored - this shouldn't be a problem and you can decant the wine into another bottle. Before your event, chill the wine, carefully open it and have a small taste - it could be OK, however rhubarb can have an excess of malic acid that is not to everybody's palate. Usually, red wines improve over a few years if stored correctly but whites are generally best when young. If in doubt - chuck it out! I've generalised a bit, but for the cost of buying a bootle or two (or 3 for a tenner at your local supermarket) minimise your concern by just having the rhubarb wine yourself and not have any worries at the event. Cheers, Andy