Colored slime in an ice machine is very common. (I used to work for a water filtration company, and this was a constant problem). It is caused by the fact that they (most likely) are making their own bread on location. The ice machine is too close to the kitchen area where the bread is made and the live yeast from the bread somehow gets in the air and travels to the ice machines. To make ice, heat is actually required (in the coils of the machine) and the bread yeast finds the hot area of the ice machine and latches onto it to grow. The slime is bread yeast, nothing more. It will not effect the safety of the ice, only that it will make it "holey" in that the water can not freeze into solid pieces of ice, rather it leaves lots of air bubbles in it. So if you ever go somewhere and their ice seem flaky, chippy, or otherwise not solid, it is most likely due to yeast in their water system of the ice machine. It is VERY common. It can be fixed by replacing the ice machine water filters (very often, more so than regular water filters for water systems). Most likely, the restaurants don't even know they have this problem until 1. it is time to change the filters and they access that back area of the machine, 2. they notice a difference in the consistency of their ice, or 3. (most common) the health officials find it. Like I said, it does not effect the safety of the ice, only it's consistency.You will see this same problem at any restaurant that makes its own bread or at places like Starbucks and Subway as well, two of the vendors I used to manage and would get constant frantic calls from. Nothing to freak out about.
@allymansfield:
So that was very educational. Thank you. Question? What about the color of the slime? Any difference in the scenario? 4951