Coke itself is not consumed in a containerless 0g environment so the container itself imparts taste - hence why aficionados will often prefer glass over pastic or can. The bottling processing factory will also impart a taste, as will the local humidity which is why I often think drinks taste odd in Singapore.

My fav thing I heard was back in a chemistry lab someone told me a rumour coke had invested serious R&D into a plastic/surface that tastes like lemon to accommodate for the regular plastic taste that leaches from their bottles.