I started dehydrating my starter today at 12:30pm and 6 1/2 hours later I find these blackish greenish spots. Is this some kind of oxidation from the oven racks, is it mold that formed in 6 1/2 hours or is it something else???? I’m clueless and wondering if I have to throw this out. My starter was healthy with no mold when I spread it on the parchment. Could it have molded so quickly?