It was on its way to collapsing into a flat slump, so I saved using the old trick of using a nylon scraper and pulling from underneath over the top to the other side. Did it all around until it got tighter. Then popped in a 500F oven with steam, lowering 10F every 5 mins to 460F until done.

I'm using a cheap ($2.99/5 lb) store-brand 13% protein bread flour. Definitely a strong flour. This is a continuation of my previous tries with it: https://www.reddit.com/r/Breadit/s/E9osyZR9o0

Decent large crumb, though uneven with some crater-sized ones. Still, it makes great toast & sandwiches.

400g BF, 78% hydration (312g water), 90g levain, no extra yeast, 7g salt. Stretch & fold kneading, bulk rise, wide stretch/fold lamination, shape, final rise, (**) bake.

(**) Don't do what I did, which is forget..