sourdough

How Baker's Percentage Works: The Math and Science Behind Sourdough Fermentation

How Baker's Percentage Works: The Math and Science Behind Sourdough Fermentation Baker's percentage is a ratio system where every ingredient is expressed relative to total flour weight, which is always 100%. A "70% hydration" dough contains 700 grams of water per 1,000 grams of flour. This single number — hydration — determines whether your crumb is tight and uniform (60-65%) or wild and open (80-85%). But the percentage only sets the stage. What actually builds your bread is fermentation: a biochemical process where wild yeast produces CO2 for rise while lactic acid bacteria produce the acids that define sourdough's flavor, extend its shelf life, and reduce its glycemic index by up to 25 points compared to commercial bread. At UseCalcPro, we've watched thousands of bakers plug numbers into our sourdough tool and then ask the same question: "I got the right amounts, but my bread still came out wrong —...