Hi babygirl,
that depends on many factors. Water freezes when its temperature falls below zero Celsius (that is for pure water). How 'fast' that happens depends crucially on the temperature of the water you started with (say whether it was just boiling, or just unfrozen?), it depends on the way you cool it (say, you put it in the freezer, or drop it into liquid nitrogen), it also depends on the amount, or on the way you store it respectively - a larger surface makes heat exchange easier and therefore the water will freeze faster (if you spay some drops into the freezer they will freeze faster than a whole bottle of water). Best,
B.