Calculate precise ingredient weights for sourdough bread using baker’s percentages and hydration ratios.
2026-04-14T00:00:00Z
Base ingredient (100% in baker’s math)
Water as % of flour (65-80% typical)
Typical: 1.8-2.2%
Inoculation rate (10-20% refrigerated, up to 50% ambient)
100% = 1:1 flour:water (standard). Adjust if your starter is thicker/wetter.
Baker’s percentages represent all ingredients as a percentage of the flour weight, which always equals 100%. This system allows recipes to scale infinitely while maintaining consistent ratios and flavor profiles. For example, a 75% hydration means the water weight is 75% of the flour weight. This method is far superior to volume measurements (cups/tablespoons) because flour density varies with humidity and settling — an unsifted cup can contain 20% more flour than a sifted cup. Professional bakers worldwide use this system because it removes guesswork and produces reproducible results regardless of batch size. Sourdough specifically benefits from precise hydration because it affects gluten development, rise times, and crumb structure; even small variations (±5%) noticeably change the final bread.
The starter percentage is especially critical in sourdough. Inoculation rate — the percentage of starter relative to flour — directly determines fermentation speed. A 20% inoculation (1:5 ratio of starter to flour) with refrigerated starter will undergo slow, cool fermentation over 12–18 hours, developing complex flavor and strength. The same dough with 50% inoculation ferments rapidly in 4–6 hours, producing less sour bread. Salt percentage is more forgiving (2% is the sweet spot for most palates), but it’s still included in baker’s math for professional consistency. This calculator uses these ratios to scale your recipe precisely — whether you’re making 250g test batches or 5kg production loaves, the proportions remain identical, ensuring your techniques translate across any scale.
Start at 75% if you’re new to sourdough. This creates a dough that’s moderately sticky but manageable. As you gain skill, you can experiment with 70% (stiff, more shaping control) or 80% (wet, open crumb) to suit your environment and preferences.
Inoculation rate directly controls fermentation speed and acid development. Low inoculation (10-15%) creates slow, complex fermentation with more organic acids and flavor. High rates (30-50%) ferment quickly with less sourness and tang. Cold retard (refrigeration) naturally slows any inoculation rate, building flavor during the long final proof.
Yes indirectly. Your starter percentage and proof time compensate for temperature. In cool kitchens (< 65°F), use higher inoculation or extend fermentation. In warm kitchens (> 75°F), use lower inoculation or shorten times. The recipe weights stay the same, but fermentation timing adapts to your environment.
Absolutely. That’s the beauty of baker’s percentages. Want to make 4 loaves? Multiply all weights by 4. Want a small test batch? Divide everything by 2. The percentages never change, so your techniques remain identical across any scale.
Hydration perception depends on flour type and gluten development stage. During bulk fermentation, the dough becomes smoother and easier to handle as gluten develops, even without adding water. If dough is shaggy at mixing, it’s probably normal. Add water only in small increments (5g at a time) if truly difficult to incorporate.
Look for 50-75% volume increase and a smoother, slightly domed surface. The poke test confirms readiness: gently poke the dough; it should slowly spring back halfway. If it springs back immediately, it needs more time. If it doesn’t spring back, it’s overfermented.
Whole grains absorb more water, so you may need to increase hydration 5-10% when substituting. Whole grains also ferment slightly faster due to enzymatic activity from the bran. Start at your calculated hydration, then adjust based on dough feel in the first bulk fermentation.
One cup of flour can range from 100-150g depending on how it’s measured and stored. This variance ruins consistency. A scale ensures you get exactly the same hydration, salt concentration, and fermentation behavior every bake. Investing in a $15 digital scale eliminates 90% of common sourdough failures.