I have a rather large Staub cocotte with the black enamel interior, and I've had it for about half a year now. However, one thing I have been noticing is that its been getting very discoloured and/or stained inside. These stains have a rainbow sheen to them like oil, and some are white (the white ones are mainly on the sides, the rainbow ones are on the bottom) They disappear when I apply a thin later of oil to the enamel. The tap water where I live is not very hard at all.
Does anyone know if this is normal? Has anyone experienced this before? I emailed Staub and they told me to bring the cocotte to their closest sales point to have it checked, but it is big and heavy, and I'd rather not have to do that unless I know its not normal.
I will add photos soon if I can get any that actually show the stains properly.
I have a very small cocotte as well which I use more often, and this has similar stains, but to a much lesser degree (and the enamel texture is different in the small one, which is black all over including the outside and the interior is a bit more textured, unlike the big one which is graphite grey on the outside and smoother on the inside).