Just finished an experiment where I upped the hydration to 85% using 25% whole wheat and the bread looks and tastes great but for the fact that the crust is paper thin. Does anyone know what causes this?
It looks like you might not be scoring your bread before baking. This might mean that the bread is stretching to its limits - but not splitting - and thus creating a really thin crust. Try scoring your next loaf and see if this is the issue. https://blog.kingarthurflour.com/2017/08/04/scoring-bread-dough/ (I’m just picking up baking after a 20 year hiatus, so my opinions are VERY suspect!)
You are right, of course, that I didn’t score this loaf. I usually do but was afraid of deflating the high hydration dough if I did that.
I honestly feel that scoring is mandatory - it allows you to control how the bread will expand and break. Your bread had high hydration and probably also a very, very elastic gluten property, so it inflated like a balloon. And, like a balloon, it stretched thin. That’s my best guess, at least. I did the same once and rectified it by scoring. Baking is a lot like chemistry - complex! Variables like water and different types of flour can really change the bread. See what happens when you score - and let us know how it goes.
Oooo, I am glad someone brought up that question. I am to a point with your sourdough bread recipe that I don’t even read the directions anymore and I encountered the same problem with my last two loaves and voilà It was because I had neglected to score the top before baking.