New to sourdough — is this mold or normal starter activity?

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I can’t tell if it’s normal residue or something starting to go bad.

Hi everyone!

I’m new to sourdough and I’ve just started my first starter. I can see some signs that it’s been rising and falling on the sides of the jar, but I also noticed a few spots on top and I’m not sure if it’s the beginning of mold or something normal. Could someone please take a look and tell me what you think?

Thank you!


 

The only thing I see in the picture is small bubbles. They look normal.  If you think there are other things too, please show the top of the starter from some different angles.

TomP

Residue on the sides over time will mold if left to build up , in my experience. I use a table knife to stir my starter while scraping the sides clean . 
You can store your starter covered in the fridge til needed. When ready to remove some to build for baking  you can give a good scraping stir, remove however many grams desired and store again in the fridge. 

Another tip to prevent “ hooch” build up if your starter isn’t used to bake very often is to keep it at a lower hydration . I keep mine quite thick. This also prevents the residue on the sides better than keeping a 100% hydration starter. 

Congratulations on your success and please post your bakes. 🙏