Maltose is a disaccharide (simple sugar) produced when amylase enzymes break down the starch in flour. It is the primary fuel source for the sourdough ecosystem. Uniquely, the bacterium F. sanfranciscensis prefers maltose over glucose, giving it a competitive advantage in wheat dough.

Water is not just a filler; it is the trigger. Flour in a bag is biologically dormant. It is only when water is introduced that the enzymes (amylase and protease) wake up and the biological clock begins to tick.