Grano arso (lit. burnt grain) is a prized Italian flour variety that's produced in Puglia. It's also a fine example of la cucina povera. This burnt flour is prized for the toasty, smoky, nutty, and earthy flavors with hints of coffee that it imparts on breads and pastas.
It can be traced back to the 18th century, when the poor villagers would collect the scorched grains that remained on the ground after farmers burnt their fields so they can make new crops. There are other claims that the poor peasants would sweep up the burnt flour off the floor of communal ovens after the bread was baked.