I tried making a yeast starter from 2 bottles of saison DuPont. I boiled a solution of 100g of DME to 1L of water. I added half of it to the dregs and put it on a stir plate. I took the remaining half and left it in an air tight container at room temperature. After 24 hours I added the other half to what looked like a nice starter. After I added the solution that had been sitting I noticed a smell from the jar (not the flask on the stir plate). It wasn't bad, just different. It was a sort of cooked cereal rather than a fresh cereal smell of normal wort. It also had a greyish trub (which I did not add). Could the solution go rancid? Are there risks of botulism? I added the "questionable" wort about 12 hours ago. It looks and smells ok. The color is milky yellow brown and it has an inch of frothy head. Any thoughts?