Bread – Why does dough break when kneading, and how to prevent/ameliorate it

I have to contradict @saj14saj here. I have frequently had bread made with underdeveloped gluten (my grandma uses AP flour and tends to knead very short, 2-3 minutes per hand, and use very short proofing times). The bread is soft and cakelike, but it has no trouble rising, and it is neither flat nor dense.

On the other hand, I have had bread with exactly the same symptoms as yours - first feeling great, then left out for a long time to proof. After that, it looks good, but one touch makes it collapse into itself. The reason was very clear: overproofing. There is no doubt that underdeveloped gluten cannot have been a factor in my case. First, I am experienced enough to know when my gluten is developed - the bread was kneaded well beyond windowpane test. Second, it was a large batch of dough. I baked the first loaf at the optimal time and it rose just fine and had a nice texture with traceable gluten sheets through the crumb. It was the second loaf, which I baked a few hours later (and the proofing loaf spent them in a 30 degrees celsius kitchen in summer) which made the trouble. The dough had exactly the "loose" feel you describe, unlike the normal, springy feel before the proofing. It collapsed on touch and would not rise at all. It also had a very strong yeast fermentation taste, unlike the other loaf.

From your description and my experience, my conclusion is that overproofing until your starter died in its own waste products is the most likely culprit. The simple answer would be to not let it sit out overnight. The right amount of time to let it sit would depend on the room temperature, on the amount of starter you used, but also its leavening strength, and that is a bit hard to judge for a newly created starter. My best suggestion is to use trial and error and maybe bake 4 hours after knocking instead of 8 next time, and the time after that adjusting with a smaller increment in the right direction depending on whether the bread turns out overproofed or underrisen.

I can think of one case where yeast doughs shouldn't suffer from mechanical mixing:

• If you're going to be rolling out the dough (eg, for filling & making dumpling-like products, or rolling balls for monkey bread), you'd normally end up compressing the air bubbles when rolling it. Mechanical mixing has the same problem, so the difference between hand-kneaded and mechanical-kneaded shouldn't be noticeable.

I also tend to use a mixer on doughs that have so high of a hydration that they're more batter-like ... but I'm starting to question that practice after your question. (they're not that hard to stir with a wooden spoon ... it just takes a little time).

Most of the breads that I make in my mixer are enriched breads (lots of butter or milk), and have small bubbles. (what rumtscho refers to as 'cakelike crumb').

I also use a mixer on breads that take so long to knead that I wouldn't make them without a mixer -- it might result in an inferior loaf, but it's either a fresh slightly sub-par loaf, store-bought (which is likely also machine mixed), or no bread at all. You can work some larger air bubbles back into the mix by not punching it down (or doing it gently), but using a more gentle stretch and fold before shaping and the final proofing.