I wondered if anyone has any ideas about this one. I've been upping the hydration to 100% on an 80% WM sourdough with generally good results. The dough is much less dense and very moist and springy, BUT I am getting a little line of compacted under proofed/baked dough as can be seen in the picture. When I was using 65% hydration I didn't have this problem. In both cases I've been overnight bulk proofing, then pre-shaping in the morn and sticking in a banneton to prove for about 45 mins before bake. Any more and the dough just spreads too much. Maybe it needs a longer final proof at the risk of a flatter loaf? Welcome any ideas. thanks.
Have you had to reduce the fermentation times? How does the outside crust colour compare to earlier loaves?
The crumb looks like it is falling or compacting above the bottom crust. Why? Overproofed or underdeveloped gluten matrix comes to mind. Might be helpful to see the whole crust crumb shot.
Might be there is just too much water in the recipe.
Idea. Try backing down or try to include some chia seeds in the flour. Chia soaks up 4 x it's weight in water. The difference between 65% and 100% is 35% so try 7 to 8% chia seed. Chia will soak up the water and then give it back during the bake and you will be able to control the shaping with a stiffer dough.
Does this show anywhere else in the dough?
I was trying a different mixing technique the other day (autolyse without starter) and I got a section of the dough dense and under fermented which lead me to think I didn't incorporate the starter well enough.