I just uncorked a bottle of Faustino V Rioja (2001) and I noticed that the cork had a "trickle" of a wine stain all the way from the inside part to the top. The aroma was of green olives, almost sour at first. I've never had rioja before and I'm too new to wine appreciation to determine if the wine has become oxidized. I have not yet tasted it, but have decanted it and will be tasting shortly. What are some taste clues that I should be aware of to verify if this bottle went "bad"