I received a bottle of Zenato Amarone Classico 1995 several years ago, maybe eight. I completely forgot about it on a shelf in the basement. How do I know if it is still any good?
I'd open it soon and not get my hopes up. Amarone is a full-bodied, robust red designed for cellaring. In an ideal world, that Zenato should improve with up to 15 years in the cellar, perhaps longer. However, like all wines, it must be kept considerably cooler than average basement temperature – ideally 13 celsius versus 18 or 19 – if it's to go the long haul.
Was it standing upright rather than horizontal? That's critical. If upright, you may have a problem. The cork will likely have dried out, letting in too much air, and that spoils wine. (It may also crumble when you attempt to pull the cork, a sure sign that it dried out.) Check the fill level. Has the volume noticeably declined such that the fluid surface is closer to the bottle's shoulders than the cork? There should be no more than a centimetre and a half between the base of the cork and the liquid's surface at this point.
I can't say with certainty that your wine is toast. It may in fact be fine. Amarone can withstand punishment more than most wines. Just don't expect nectar of the gods.