JennyR wrote:Looks good to me Mick, I've never heard of putting it in a cold oven before!
Elizabeth David mentioned it (with slightly surprised approval IIRC) ...
Jeremy it may not be the 'ideal' way to do it but for someone who's short of time and doesn't have the luxury of a few spare hours to warm the loaf up the knowledge that a perfectly acceptable loaf can be made like that is very useful. Given a choice of no bread, shop bought sliced loaf from corner shop or a loaf like that I know what I'd rather choose!
It takes longer for the full heat to penetrate to the middle ... so, the under- crust dough will be baked while the centre is still springing. This is going to happen normally, but it will be accentuated by the middle starting off about 20C colder than normal. That's why there's a tendancy to 'blow'; its swelling in the middle, but all round, it has firmed up - so it could burst out anywhere...
Maybe the answer is especially deep slashing?
And to go for long slender shapes rather than boules, so the middle gets its heat sooner?
Or wetting the outside of the dough, so it stays stretchy longer?
Or all of these

and more?
I think a fridge is a fridge, if mine gets any colder it's a freezer, 2-5 degrees c. I don't think many people have the luxury of an old fashioned larder these days, houses aren't built with them anymore.
I did some measurements inside my fridge (with a mind to meat curing). The variation was quite surprising, not just top to bottom, or with time, but there actually seemed to be more variation when the fridge was fuller.
And that's quite apart from the different conditions depending on whether or not the door is opened frequently!
HOWEVER, whether the fridge is at 2 or 7C doesn't make much difference. Yeast dies at about 52C. Normal dough might be at 25C. So the middle of the cold dough needs to be heated
by 45 to 50C (instead of only by 27) before the 'springing' (from yeast, never mind steam) stops.