Unopened slashes equals overproofing?
Unfortunately my camera is not working at the moment (due to an accident in which it took a tumble into a beer glass) so I'm going to have to use hopefully not quite a thousand words to describe how my bread turned out.
Essentially I'd like to know why my slashes didn't open up much, I baked a wholewheat batard, at 79% hydration with a mix of high gluten flour, 5% rye flour and 10% wholewheat sourdough starter, but the main raising agent was dried yeast. I slashed it and baked it with steam for 40 mins. It had a brilliant oven spring, one of the best I've ever gotten, I think due to kinda getting the hang of the stretch and fold and some fairly decent shaping. I haven't gotten a chance to look at the crumb as I took it out of the oven about 10 mins ago. The main thing is that my one long slash along the top of the loaf didn't really open up at all, is this a symptom of overproofing? I hasn't got any other symptoms such as poor oven spring or pale crust though. I did leave it for its final rise half an hour more than I had planned as it still sprung back a lot when I poked it, but I haven't got a lot of faith in my ability to tell when bread is ready for the oven. It may be a simple question of having not slashed deeply enough.
Thanks a lot for your suggestions,