Here is the second one at 68 %
Are you using (percent wise) and how long are you proofing. These look like what I like to describe as 'foamy' (not a bad thing just a type of crumb) whereby a lot of yeast was used to with a fast proof that infuses a lot of gas. Typically low yeast quantities and long bulk proofs with short final proofs make for more structured bread (again just speaking from personal experience ) - basically I will expect something like this if I push yeast percentages and see a fast rising dough then on the other hand introducing just a little yeast (as in .3% idy) then let the dough proof overnight at 4c from here shape and final for 40 minutes the shock the loaf at 500f causes fewer gas cavities go from 1mm to 1cm. Or you think about its all about the energy and its incredible how by raising the temperature the co2 will really dramatically expand. If there are too may of them they are all competing for space so one thing to consider is actually minimizing how rapidly the yeast is performing. If you are working with sourdough to some extent the yeast factor is on your side as it tends to be a slower process just by virtue of the concentration of yeast in a levain but if working with ady or idy then things are a different story - the stuff is supercharged and designed by scientists to work fast and efficiently. Other than that the loaves have sprung rather nicely - its hard of course to diagnose by a picture or two but these are just some initial observations and thoughts - jidt keep plugging away !
I was playing around with 5 to 10% and those bulk ferements were taking at minimum 20 hrz at about 72 degrees then proof for another 2-3 hours. I'm thinking my starter just wasnt at the best portion of being alive and I'm making some loafs tomorrow and will see if this is the issue.
Sorry asked this question on your other thread so I was assuming you were using commercial yeast sourdough is a totally different animal that I barely touch (mostly as I don't really dig the flavor profiles) however it looks pretty active what temp are baking these at and for how long ?