I have a three-litre unopened bottle of Henkell Trocken, which I purchased around 1988 at a Toronto wine show. Would it still be useable? Would it have any resale value?
"Useable" is an apt word. That bottle could make a good doorstop but I wouldn't hold out much hope for the flavour.
Henkell Trocken is a popular sparkling wine from Germany, priced at roughly $14 or $15 around the country. It is soundly made but not designed to be cellared for three years, let alone decades. In fact, generally speaking, the only bubblies that can survive the long haul are French "vintage" Champagnes – the superpremium bottles stamped with a vintage date on the label.
That said, you raise an interesting qualification. At three litres, your wine-show trophy is gigantic. Large-format bottles tend to preserve wine better. There's more fluid in the container, so the rate of oxygen absorption through the cork is slower.
I only wish you'd written me in, say, 1995. I'd have told you to start thinking about popping that cork then. Today? I'm guessing your Henkell's over the hill. This also presupposes it's been stored in a cool, dark, humid cellar. A broom closet will have accelerated its demise.
This, I'm sorry to say, pretty much answers your second question. Resale value? In German, I believe the word is nichts or null. As in zero.
Beppi Crosariol is the co-author, with Lucy Waverman, of The Flavour Principle, a sumptuous new cookbook and drinks compendium, published by HarperCollins.