Ouch. One big hole is bad, bad, bad. And maybe err on the side of underproof. But, my last loaf was severely over proof and I think I prefer it under.
Still, this makes for a decent loaf. Just a slight tinge of sour with nice, crispy crust. It will do.
Starter feed: 20g starter + 50g bread flour + 50g water; 2315 24th Aug
Dough: 340g bread flour + 45g rye + 9g salt + 270g water + 105g starter; Start knead: 5 min + 5 min; 1015 25th Aug
1st fold: 1058
2nd fold: 1134
3rd fold: 1203
4th fold: 1233
Pre-shape (+ 50g cheddar): 1412