Hey guys, I have a small problem with my sourdough breads. I use a standard wheat starter, and try to work out from the method described in Tartine book - going for aprox 70% hydration. I mix my leaven, let it bubble up, mix my dough sans salt. After a half hour I work in salt and a little more water and sort of handknead it until it has a nice soft consistency and it starts sticking to my hand again. Put in box, "turn" once every half hour for like 3 hours. Pour on table, do a stretch and fold 4 times at 10 min interval, then shape up a nice package which does feel tight and the gluten is well developed. (Infact, already when I remove the dough from the cointainer after the turns I can usually take a hold of the top of the dough, pull, and the entire dough will come out from the container without any breaks.)
I transfer to a towel covered banneton and slap it in the fridge overnight. Next day, take it out, let it rise for 3-4 hours until it can pass the poke test. But now comes the problem; when I transfer it to my dutch oven baker thingie, it is as if though the loaf halves in height and doubles in width - sort of flats out. As if the structure of the loaf is simply too "loose", if this is the correct term. I am abit at a loss as to what to do here. It seems as if though you are not supposed to knead for any length of time to develop the gluten. Doing the turns should be sufficient for that, and stretch and folds should tigthen the outer surface of the dough for it to hold its shape. I should mention I make "long" breads, not circular ones. Any help and advice you can offer I will really appreciate!