Poolish method, need advice for last phase before baking
So, I have been working on this recipe for a bit, trying to make my first perfect loaf.
I make 200g of poolish and let it ferment overnight. Then 400g of strong flour 00, 270g of water, 13 g of salt. I let it sit for at least 30 minutes, then slap and fold 15-20 minutes and then let it grow throughout the day. When I come home the dough has grown nicely but I am always a bit uncertain on how to handle this last phase.
Despite I fold it and give it shape 30 minutes before putting it in the oven, it always tend to spread flat. it does not remain very round. What could be the cause? Once the dough is nice and airy after hours of growing, what do you do before baking it?