text: Suprise, suprise!  Bacteria grows better in acidic environments.  Remember, if you eat something with bacteria on it, it goes into your stomach where it's very acidic, and you still get sick.  The reason the water broke your hypothes is as follows...\n\nThe orange juice, just like other food, is treated with extreme ultraviolet light at the factory.  The ultraviolet light kills the bacteria.  The water that you used may not have been treated with ultraviolet light.  This means that the water actually had bacteria in it, whereas the orange juice did not.\n\nI hope this helps.