Cannot perfect the crumb... please critique my bread making process.
This is the bread I've been working on for 6 months. I've made it probably about 70-80 times, it tastes amazing, the crust is perfect, and it has a ton of oven spring. However I just can't get that nice open crumb I am searching for. So after many futile attempts I thought someone here might be kind enough to evaluate my technique and recipe and perhaps point me in the right direction.
400g Bread flour (80%)
100g Rye meal flour: (20%)
360g Water (72%)
1.25 tsp salt
1st build (1:4:4): 25g starter + 50g rye flour + 50g water (save all but 40g for next batch)/ 8 hours
2nd build (1:4:4): 40g starter + 80g rye flour + 80g water/8 hours
Starter ends up being 100g rye flour, 100g water
Then, I add the starter to 400g of white bread flour and 260g water. Comes out to 72% hydration.
Then I let rest for 2 minutes, and hand knead for 10 minutes. I let rest for 2 minutes, then knead for another 2 minutes.
One full rise (4 hours), then I stretch and fold, deflating and also redeveloping the gluten, then I put it in the fridge for 16 hours. The following afternoon, I take it out of the fridge, stretch and fold, then let it rise again (4 hours).
Finally, I do another stretch and fold, and then make a sort of package like shape with the dough and do the boule forming trick where you pull it towards yourself and keep repeating while rotating the dough. It gives it good surface tension.
Then I prepare my colander with a couche (heavily floured and oiled cut up cotton shirt) and let it proof for about 2 hours. I've found its better to slightly underproof this bread.
I bake it on a quarry tile at about 500f for about 22 minutes, rotating the boule at 10 minutes into the bake. I give it a good amount of steam for the first 3-4 minutes.
Ideas? Constructive criticism?