We did a rock candy experiment in 6th grade and probably attempted it a few separate times, specifically because we kept having issues. I think at least one bat

We did a rock candy experiment in 6th grade and probably attempted it a few separate times, specifically because we kept having issues. I think at least one batch got moldy. But, if I'm remembering correctly (this is over a decade ago), we may have been placing the dishes near where sunlight hit, so that could've been part of it.