I opened a bottle of red wine last night and found a dark red/black grainy gunk all over the bottom of the cork and around the neck of the bottle. It looked sort of crystalized on the bottom of the cork, like black salt crystals. The wine tasted like it had been open for 3 days...just flat and gross, but no "off" or rotten flavor or aroma. What happened? I assume the cork was letting air in or something to oxidize the wine...but what was the gunk? Is this what is meant by a "corked" wine or is this something elese?