I am very new to sourdough baking, having only made a handful of loaves.This is my most recent attempt at a white sourdough, following Dan Lepard's recipe. Following shaping, a proving time of approximately 4.5 hours is recommended, "or until the dough has approximately doubled in size / height". I realise proving is an inexact science and am doing my best to gauge when the dough is proved sufficiently by look and feel. For the loaf shown above time constraints required me to put the dough in the fridge overnight in a teatowel - lined pyrex dish. Total fridge time was 7 hours, I got up next morning and took the dough out where it rested on the kitchen worktop for about 75 mins while I preheated the oven. I should say everything looked exactly the same as when I put it in the fridge the night before When it came time to bake - when the oven was hot - there was a decent spring and I was happy with how it baked. On cutting however, there was a bit of "flying crust" - large holes in the centre with a more dense crumb top and bottom which was a bit disappointing as I expected it to be my best to date.
What is more interesting is that I kept aside a smaller piece of dough the night before and left that to prove on the kitchen bench covered in a dusted banneton. I baked that before my main loaf and there again was a decent spring but there were none of the large holes inside. Again it didn't look to have risen much at all overnight.
My question: Is it possible that the conditions of my kitchen (ambient temp overnight 16C - 18C) are allowing for a prove of that length? When I poked the dough that had been left out overnight there was minimal spring back.
Thank you in advance for your help.