Possibly the stranges topic I've seen on this site, but I regress; If your body doesn't want it, you'll know. Other than that you can try to expel it by drinking a whole lot of water in one go, but it's not a healthy idea because it then floods your system with unneeded resources and can make you overly thirsty later. Like Zaracron said though, I find it VERY weird that this site was the first one you thought of to ask this about. Common Sense bro. Also, try smelling it next time, or let alone tasting it. Surely you can't have drunk the whole lot without at some point thinking "Hmm, I wonder why this tastes like absolute shit".