I made a slow baked Finnish rye over the past few days. It used a two stage sponge with malt and buckwheat added to the mix. Very interesting.
Anyway, I botched the final proof, misjudged time, threw it in fridge a few hours where I kept proving. This caused a collapse while in its 6 hour bake. Yes. 6 hours. Lol.
It'll still be a good one I can tell. Smells fantastic. Here's the collapse. It's small.