You are not alone but it could just be your own judgement affecting the taste. A research study found surprising results that certain people actually are affected by the container that holds a beverage. They have termed these people High Autotelics. They tend to touch more and receive pleasure from touch. They will judge the same beverage that is held in a porcelain cup to taste better than one in a flimsy plastic cup. Hm.. come to think of it, I might be one of them. I always thought the plastic affected the taste of my beverage! Read this link for the research details.