Baker's Percentage System

100%

Flour — The immovable anchor; if a recipe uses multiple flours, the sum of all flours equals 100%

variable — typically 60–85%

Water (hydration) — Hydration percentage; the single most consequential variable in bread texture

1.8–2.2%

Salt — Flavor and fermentation control; rarely departs from this band

0.5–1.5%

Commercial yeast (instant) — Lower for long cold ferments, higher for same-day baking

10–30%

Sourdough starter (levain) — Expressed as a percent of flour; itself may carry sub-components

0–10%

Fat (butter, oil) — Enriched doughs approach 10–20%; lean breads use none

0–10%

Sugar — Affects crust color and yeast activity; sandwich bread ~4–6%

1. Decide batch size by choosing a flour weight (e.g., 500 g). 2. Multiply each ingredient's percentage by that flour weight to get gram amounts. 3. To scale, change only the flour weight anchor and recalculate — all percentages stay fixed. 4. When writing a formula, list flour first at 100%, then list all other ingredients with their percentages beneath.

• Always weigh ingredients — baker's percentage is meaningless in volume measures because density varies.
• Hydration percentage is the fastest diagnostic: below 65% = stiff dough; 65–75% = standard; above 75% = slack, requires bench technique.
• Salt above 2.5% noticeably retards yeast; below 1.5% the dough tastes flat and ferments unpredictably fast.
• When comparing two bread recipes, convert both to baker's percentages first — apparent differences in ingredients often vanish, revealing the same underlying formula at different scales.
• Sourdough levain carries its own flour and water; to compare apple-to-apple, convert levain to its 'flour contribution' and 'water contribution' and fold them into the main dough totals before comparing hydration.

• Total flour as anchor (blended flours)

  If a formula calls for 80% bread flour + 20% whole wheat, both percentages still sum to 100%; water and salt are still calculated against the combined flour total

• Pre-ferment sub-formula

  A poolish or biga is written as its own mini-formula (its flour = 100%), then the pre-ferment percentage in the main dough is the pre-ferment weight as a share of total dough flour

• Inclusion percentage

  Mix-ins (seeds, cheese, dried fruit) are expressed as a percentage of flour weight on top of the dough formula, e.g., '20% sunflower seeds'

• Bread Hydration (Lean Dough)

  Hydration is the most-watched baker's percentage variable

• Sourdough Hydration (65–85%)

  Sourdough formulas are written entirely in baker's percentages

• Salt to Flour Ratio in Bread (1.8–2.2%)

  Salt percentage is a direct baker's percentage read-off

• Sourdough Starter Feeding Ratio (1:1:1, 1:2:2, 1:5:5)

  Starter feeding ratios translate to baker's percentages within the levain sub-formula

1. 1.The Bread Baker's Apprentice — Peter Reinhart (Ten Speed Press, 2001)
2. 2.Modernist Bread — Nathan Myhrvold & Francisco Migoya (The Cooking Lab, 2017)
3. 3.Professional Baking — Wayne Gisslen (Wiley, 7th ed., 2016)
4. 4.The Art of Baking Bread — Matt Pellegrini (Skyhorse Publishing, 2011)

Confidence: high