Renania Panaderia
Güemes 2622
if you are willing to travel a bit . Spectacular breads,established since 1953.
If you go to panaderias that do not have the bakery on site the staff probably only know "their" name for their bread, not the ingredients. Bread names vary between chains a la hausbrot and according to the traditional ethnic mix of the barrio, eg in Villa Ballester people probably won't bat an eyelid, if you ask for roggenbrot in German, Recoleta not so much. Some have spanish names like hogaza de Rogge and all variations in between .