Oh, that's so frustrating, Jackie! The odds are pretty good that you aren't doing anything wrong, you've just got a source of mold spores somewhere nearby. Thoroughly cleaning your container, using a not-quite-airtight lid (rather than a cloth like some people use), and perhaps moving your starter to another room of the house can help avoid this. You'll also want to check any hidden areas in your kitchen for the source of the mold, since we presume it's not flying in through open windows this time of year. Behind appliances and under the sink are two common culprits. Best of luck, and happy baking!

• Reply