I recently bought a ceramic slow cooker insert at a thrift store. It has a glass top and is the perfect shape for using as a Dutch oven in baking bread, which I do regularly. When I got home, my husband found a hairline crack going down the side. I’d like to know if this is still usable. Here’s the method I currently use with my cast iron/enamel coated Dutch oven:
I preheat the oven to 500F with empty Dutch oven, with the lid on. When it’s reaches temperature, I take my shaped dough from the fridge where it’s been all night in a bowl on parchment paper. I slash it, then lift it by the parchment paper and place it in the Dutch oven. Sometimes I slip some ice cubes under the parchment before putting the lid on, although I could skip this step if it’s not recommended.
Question: would this procedure be ok for the Dutch oven described above, with the hairline crack?
Best Answer
I would not use it for this purpose.
Your main issue with using ceramic bread cloches (the standard ceramic "Dutch oven") with the kind of recipe you have is thermal shock: you're heating the vessel to 500F, then depositing a mass of very wet cold dough inside it. This can often result in a cloche cracking. This is why cloche manufacturers direct the owner to heat the cloche with the dough in it.
In your case, you're taking a vessel that was never meant for temperatures above 220F, which already has a crack in it, and preforming that routine. I'd fully expect it to crack in half as soon as you introduce the dough.