The upside of this is that I haven’t made this mistake for a while. My boule was over-proofed before my oven was ready — you could definitely tell. The outer skin of the loaf was very soft and almost ready to fall in; it wasn’t even firm enough to properly score.
The problem? I can track it all the way back to my dough prep — where quickly measuring my yeast by pouring it into the mixing bowl on a digital scale, I went too fast, and instead of adding 5 grams to a 500 gram loaf (1%), it spilled. I used a spoon to recover most of my spill, but still ended up with closer to 10 grams than 5 grams. And as a result, I had some very lively dough. Boing.
The final bread has a very thin and soft crust, and it is very short and wide. It definitely sagged when I removed it from the baneton, scored it, and loaded it into the oven.
This was an 80% hydration loaf, with 80% whole wheat, 20% white whole wheat, plus 10% flax seed bran, 7% honey, 5% olive oil, 1% yeast (well, not really), and 2% salt.
Another loaf another lesson. It will be fun eating the evidence.