More or Less Water in Sourdough: How to Adjust Hydration

Practical guide for adjusting sourdough hydration: how hydration affects crumb, handling, fermentation, and how to change water in a recipe with reliable tests and troubleshooting.

Overview

Hydration is the ratio of water to flour in sourdough dough, expressed as a percentage. Higher hydration (more water) typically yields a more open crumb, thinner crust, and softer mouthfeel; lower hydration yields tighter crumb and easier handling. Small changes (2–5%) have noticeable effects on dough feel and bake results, so adjust deliberately and track outcomes [1] [2].

Troubleshooting & Tips

Common issues and fixes:

- Collapsed loaf with wet interior: dough was likely over-hydrated for its strength or overproofed. Reduce hydration by 2–5% next time or shorten final proof; strengthen dough with additional folds during bulk [1] [2]. - Dense crumb despite high hydration: underfermentation or insufficient gluten development. Allow longer bulk fermentation, add more folds, or increase mixing intensity slightly. Also check starter strength — weak starter can slow gas production [1]. - Difficult shaping with high hydration: use a well-floured banneton proofing basket or a silicone bread sling to support dough; chill the dough briefly to firm it before shaping [2]. - Sticky dough that adheres to surfaces: use a dough scraper/bench knife and a light dusting from a flour duster/wand or parchment for handling; reduce hydration slightly if the issue persists.

When in doubt, bake test loaves with 2% increments and keep other variables constant — systematic testing is the most reliable way to find your preferred hydration for a given flour and environment [1] [2].

Why Hydration Matters (science)

Hydration controls gluten development, enzyme activity, and fermentation kinetics. Water allows gluten proteins (gliadin and glutenin) to hydrate and form a network; more water increases extensibility but reduces dough strength, which influences oven spring and crumb openness. Higher hydration also speeds up enzymatic activity and fermentation, because enzymes and yeast diffuse more easily in a wetter matrix. Environmental factors (flour type, temperature, and humidity) change effective hydration: whole-grain flours and fresh-milled flour absorb more water, while aged, lower-protein flours absorb less [1] [2].

How to Adjust Hydration — Practical Steps

  • Practical steps to increase or decrease dough hydration safely:
  • Use a digital kitchen scale for all measurements; weigh flour and water, not cups. Weighing makes small hydration changes consistent [1].
  • Change hydration in small increments: start with ±2–5% of total flour weight. For a 500 g flour dough, 2% = 10 g water.
  • Account for water already in your starter. If your starter is 100% hydration (equal parts flour and water), every 20 g of starter contributes 10 g water and 10 g flour; adjust the formula to keep target hydration steady [1] [2].
  • If you reduce water to make handling easier, compensate with longer bulk fermentation or more folds to develop strength without becoming overly stiff.
  • To increase hydration for an open crumb, increase water and shorten initial mixing intensity; use gentle stretches and folds to build structure gradually.
  • Example: recipe lists 70% hydration with 500 g flour and 350 g water. To test 72% hydration, add 10 g water (360 g total). Keep other variables constant and document results [1].

Simple Tests and Visual Signs

  • Use these practical tests to judge whether to add more or less water:
  • Windowpane test: dough should stretch thin without tearing. Wet but cohesive dough that passes the windowpane is well hydrated for structure; if it tears quickly, add 1–2% more water and allow more folds [1].
  • Poke test: press a finger into the dough — if it springs back slowly and leaves a slight indentation, fermentation and hydration balance are good. Very slack dough that collapses indicates over-hydration or overproofing; reduce water next bake or shorten proof [1] [2].
  • Surface tension and shaping: if you can shape a tight skin easily, hydration is manageable. If the dough slumps and refuses to hold its shape, reduce hydration or refrigerate the dough for firmer handling [2].
  • Dough feel: sticky but manageable dough is often optimal for high-hydration loaves. If it sticks to tools and hands excessively, try wetting your hands, using a dough scraper/bench knife, or lowering hydration slightly.
  • Record ambient temperature and flour brand — those changes alter perceived hydration needs [1].

Adjusting Recipes and Bakers' Math

  • How to calculate adjustments precisely:
  • Baker's formula: Hydration (%) = (total water / total flour) × 100. Include water in starter and any added ingredients (milk, eggs) when calculating total water. Include flour in starter and prefer flour pre-weights for accuracy [1].
  • Adjusting for starter: Subtract starter's flour and water from the recipe’s flour and water totals, then add the actual starter used. Example: recipe uses 50 g starter at 100% hydration — that contributes 25 g water and 25 g flour. To keep overall hydration constant, reduce added water by 25 g and added flour by 25 g, or recalculate the target hydration with all components included [1] [2].
  • Flour absorption: different flours absorb differently. Increase hydration when using whole-grain or fresh-milled flour (start +2–5%); reduce hydration for low-protein or more processed flours [2].
  • Temperature and fermentation speed: in warm kitchens, fermentation accelerates; you may prefer slightly lower hydration to slow slack dough behavior, or retard in the fridge for firmer dough handling [1].

Sources

  1. [1]
    The Perfect Loaf – The Perfect Loaf – Link
  2. [2]
    Plötzblog – Plötzblog – Link