Combine the flour, yeast, salt, and rye sourdough starter and mix on low speed until a homogeneous dough forms, about 8 minutes. The dough should have a plastic consistency, rather than elastic.
Remove the dough from mixer and bulk ferment, covered, for about 15 minutes.
Scale into 1 lb 8 oz/680 g pieces and shape into rounds. Moisten the dough by rol