i'm new to sourdough baking and need some help. i want to try out a rye bagel recipe but want to subsitute sourdough for biga. i have no idea where to start and have trawled the internet but to no avail. the biga calls for 8 oz whole wheat flour, 1/4 t instant yeast and 5 oz water.
how do i substitute sourdough in this recipe? any help would be appreciated. thanks!