I have been using a 10 gallon Blichmann Kettle for my homebrewing for about a year now. I know it is 300-series stainless steel, which should not have rust issues, but my kettle has developed small rust spots at the bottom of the kettle.
The attached pictures show the small rust spots. It IS rust; I scratched some off and tasted it. It IS in the structure of the kettle, not just a surface stain from a small steel particle that settled on the bottom. It seems like the kettle is pitting.
A Blichmann representative rquickly esponded to my inquiry. After ruling out one possible cause, they recommended cleaning off the rust, and monitoring the pot to see if it rusts further in the future. They said if it does, that they will take care of it, rest-assured. Thanks, Blichmann!