70% hydration,. with bread flour. Plenty of folding to where I get a really strong windowpane. I do bulk fermentation in fridge overnight, dough about double. Work it on the counter and get really good surface tension during shaping. Kept in banneton until double. As soon as I turn it out on my parchment paper to lower into my dutch over, it just slumps. Also, maybe related, my razor blade -- using either water or flour -- does not score sharply, but tends to snag.
I get a decent oven spring, but not sure if I'm expecting too much in terms of it keeping its shape. I can't imagine baking it on a stone without the support of the dutch oven.
Any thoughts on what I might be doing wrong?
Shape might be the Holy Grail, but it's not easy, and shouldn't be the be-all and end-all. Most of the loaves shown on this site are wider than they are high. I find that using a tin, and oven-spring, help a lot.
Now just a thought... If the dough has risen 4x before the oven, it might have too much gas in it, and be just too delicate. IMO, it's more common to bulk ferment on the bench, shape, THEN prove in fridge overnight, which gives the dough time to rest and settle. I wouldn't be looking for much rise at all.
For about one year I contiually produced a sourdough discus whenever I attempted baking. The tasted ok but a bit too dense and I never got one to be more than about 30 thick.
Talking to a friend about my failures she said her family could never reproduce cakes like their mother made back in Europe. Her failure lead to researching flour and she came to understand that our Oz flour is a diiferent consistancy to the ones her mother made. They tend to be a little harder and do not absorb moisturre at the same rate the European ones.
I have since adjusted my hydration level from around 72% that the European recipes suggest back to around 65%. The results have been dramatic and I am no longer a disillusioned sourdough baker. I also put more time into creating some skin tension on the dough.
The loaf on the left was cooked in a dutch oven, the other on an open try in the oven.
I trust this helps.
Hard to imagine this much slumping is normal.
I have experienced the same in the past. Try final shaping and put in the banneton and then straight into the fridge (place in a plastic bag first). Take out of the fridge after 24 hours or whatever time works for you. Turn out, score and straight into the oven. If you leave it prove in the banneton after removing from the fridge it will just collapse when you tip it out. Don't expect any rise in the fridge. Make sure both oven and Dutch oven are up to temperature and don't let the heat out when putting the bread in. I use a cloche as I find it much quicker to load without loosing heat.