I'm just baking a loaf that I think is over proved: it went *splodge* and stayed pretty flat in the oven. There was some rise in the oven but it was later than I'd expect. Other clues for over proving: it has a reddish crust.
Anyway, photographs if needed tomorrow (it's in the oven for another ten minutes to finish off in case it's edible, so no photographs right now!), but what's the #1 cause of cracks in the bottom of a loaf, please?
If it matters, it's a white bread loaf, shaped into a boule, and cooked on a stone.
P.S. My other loaf for the day was a rye variant of "The mill loaf" from Dan Lepard's "The Handmade Loaf". It is under proved, but that's not so bad, especially for the first time with a recipe.
I am studiously ignoring the fact that I burnt myself again. Some people are slow learners.