text: why is it that orange juice on white bread didnt grow much mold as water on white bread? i did an experiment on bread molds. my results did not support my hypthesis.in fact i predicted orange juice on white bread would grow mold the best because i know mold needs food oxygen water warm and miosture to grow. i want to know why my hypothesis was wrong 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...  the 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.  i hope this helps.