I bought kaoline clay from Beraca. I used it in my formula and send the formulation for microbial challenge test. But the lab said it was pre-contaminated. I contacted beraca and they said if you open a package, you should use it immediately. But I had opened it a few months before.
I’m wondering what is the best way to heat treat the clay to kill It’s bacteria? Is it possible to do it in an oven?
Thank you so much!