Hydration guide
Dark Rye Flour (Pumpernickel) Hydration Guide
Workable range: 90–110% · Absorption: 1.100× bread flour · Midpoint target: 100%
How Dark Rye Flour (Pumpernickel) behaves at each hydration
Dark rye (pumpernickel flour) is coarser, contains more bran, and has the deepest flavor of all rye flours. Absorption is 10% higher than bread flour baseline. Ash content 2.0%+ indicates high mineral content from extensive bran inclusion. Used in traditional German pumpernickel (100% dark rye, 24+ hour steam bake) and Scandinavian rye breads. Hamelman's pumpernickel formula targets 95-100% hydration with 100% dark rye. Can also be used as 10-20% of a wheat-rye blend for strong rye character without going fully rye. Central Milling, Bob's Red Mill, and Janie's Mill are US reference sources.
Substituting Dark Rye Flour (Pumpernickel) for bread flour
Absorption multiplier: 1.100×. When substituting for bread flour, add about 10% more water. For example: a 75% bread-flour recipe becomes 83% when using 100% Dark Rye Flour (Pumpernickel).
The calculator below is pre-set to 100%. Adjust the slider to match your target. Salt and levain percentages are the flour-independent defaults (2.0% and 20%).
Technique at target hydration
Dark rye requires very wet, paste-like dough. Scald (mix flour with boiling water) for 24 hours as pre-ferment to maximize water absorption. Pan loaves only — dough is too wet to freestand. Long, slow bake at 325-350°F for 4+ hours for traditional pumpernickel character.
Calculator pre-set to 100%
- Flour to add
- 450 g
- Water to add
- 450 g
- Salt
- 10 g
- Levain @ 100%
- 100 g
- Total dough
- 1010 g
- Effective hydration
- 100%
How the math works
Total water = flour × hydration %. Your levain contributes 50 g flour + 50 g water — both count toward the totals. You add only the remainder as fresh flour and water.
Salt % is computed on total flour weight, not final-dough flour.