Sourdough, sixth attempt
The first five were flat. This one was not, and I want to write down why before I convince myself it was luck.
Nothing changed about the recipe. What changed was the kitchen. The starter had been living on a windowsill that gets cold overnight, and I moved it to the top of the fridge. That is the whole difference. Four degrees of warmth turned a sluggish starter into one that doubles in five hours.
Everything I had been blaming — flour brand, hydration, folding technique, the shape of the banneton — was noise. The variable that mattered was temperature, and it was the one thing I had never measured.
Second thing: I had been under-proving because I was afraid of over-proving. The dough is ready when a poked dent springs back slowly and only halfway, not when it springs back promptly. Promptly means wait longer. I had been baking at promptly for five loaves in a row.
Crumb is still tighter than I would like. Next time I will try a wetter dough, but only after this one is repeatable — one change at a time, or I learn nothing again.