Not saying it does, ive drank stuff thats been sitting out for a very long time sithout getting sick. This is basically just a tangentially related fun fact but: in the absence of a limiting factor, bacteria grows following the law of exponential growth. A single bacteria that is not restricted from replicating ever would be able to convert the entire surface of the planet into that bacteria in two days. If the medium is right, it can fill that cup in minutes.