A German ligature that originally stood for 'sz', but can be transliterated as 'ss'. It is never found in Swiss German. It looks like a B, but sounds like an S. Compare to the boring language known as English, which only has the ligatures Ã and Å, which are rarely used.
The only other flour used in traditional pumpernickel is wheat flour, which is used as an ingredient in the sourdough starter, a pre-fermented flour, water and yeast mixture that combines with the rye flour to hold the bread together.
Flour is a basic ingredient in all bread making. Wheat flour is the most common type of flour used when baking with yeast. Wheat flours include bread flour, all-purpose flour and whole wheat flour. When wheat flour is mixed with liquid, proteins in the flour combine to form gluten.