Why the "residue" on the bottom of my matte black Staub pumpkin?
I recently bought the Staub pumpkin, and I've used it twice. Both times, I put a little bit of oil on the bottom prior to adding the ingredients for my stew. I'm cooking on low to medium-low for about 8 hours at a time.
The first time I washed the pot after using it, I noticed (after it dried) that there appears to be a residue or maybe a "dryness," almost like a chalkboard, on the bottom of the pot. When I noticed it, I put a layer of oil on the inside of the pot and let it "soak" for a few days. Now, after the second use & washing, it's worse and more noticeable. It doesn't seem to be anything I can scrub away (I'm not using anything abrasive...just a plastic scrubbie). It seems to be part of the pot now. What gives? I thought these pots were supposed to never need to be seasoned, clean right up, etc.
What you described is not too strange if you were cooking meats (beef) with very little liquid, and these residues are likely to be browning from the foods and as well as burned on foods. If the meats are cooked with a lot of liquid, then these residues would have dissolved in the liquid. Did you fry/sear the meat before you add the liquid?
that happened to mine after cooking fish (thick whitefish chunks, shrimp, and clams). There was a white film left after it was washed and dried. I just used it and next time I washed it I used Bon Ami and a sponge (the blue ones that are rough on one side). Cleaned up like new. It must have been some protein that left behind the white stuff. No worries, it comes off quite easily.
I have to say I am surprised to hear of all the people using abraisive scrubbers on their enameled Staubs. You say you didn't use anything abraisive--"just" a plastic scrubby, but plastic scrubbies are abrasive. Not as much so as steel wool, certainly, but they will still leave microscopic scratches on the surface that will cause food to stick over time--even the blue ones that claim they will not.
Nothing touches my Staubs but soapy water and a dishcloth. If food sticks and soaking does not help, simmer water in the pot and let it sit until it is warm, then clean again.