My poor big red pot

I heard from more people about my St. Patrick's Day post than another other post, so thanks for those.

Tonight, I wanted to share the not-so-good side of the story. Look what steaming the potatoes, cabbage and carrots did to my favorite pot.

I still can't figure out what went wrong. I thought I put in enough water to keep the whole pot steaming away. The lid was pretty tight and I added extra water a couple of times.

Is it that starches from the potato burned the bottom? Or sugar from the cabbage caused this to burn? Or is it just that I had to be more vigilant about adding water? Anyone know what I did wrong?

It's been a couple of weeks since this happened. Since then I've been scrubbing gently at it and runnin it through the pot cycle of the dishwasher. I realized that if I scrub too hard, the enamel chips.