Recently a friend asked whether rye sourdough could add "some push" to a bread they were making using grano arso, also known as "burnt wheat." Its Italian origins literally came from burnt wheat, dating back to a period in Italy when fields were typically burnt following a finished harvest, the resulting ashes thought to provide enrichment to the soil.
In today's Germany, Schlüter mehl is a similar type of flour. It's actually soaked bran that is toasted, a process that destroys its enzymatic starches which promote the carbon dioxide that, in turn, help fermentation. Instead, the Schlüter (or Grano arso) give caramelization and flavor to the bread, as well as high water absorbtion.
Grano arso is from Puglia. As yet, it is not available here. My friend's curiousity was infectious, leading me to attempt a formula along the same lines, using a rye sourdough in a durum wheat bread and including grano arso. I just toasted my durum flour to a nutty brown color and tried to use my friend's formula with my home toasted wheat. The final dough included some kamut, semola, whole wheat and all purpose flour, along with the rye sour starter. I tried to stay in line with the wheat combinations, durum, kamut, wheat, all cousin grains to make a rustic loaf. Below are shots of the process and results.