Bread & Dough Techniques

Hydration

Also: dough hydration, water percentage, hydration level, hydration ratio

The ratio of water to flour in a dough expressed as a baker's percentage, determining crumb openness, fermentation speed, and handling characteristics.

English technical baking term; 'hydration' from Latin 'hydro' (water); the percentage notation became standard with the spread of baker's percentage in professional curricula

Definition

In baking, hydration refers to the percentage of water in a dough relative to its total flour weight, expressed using baker's percentage. A dough made from 1000 g flour and 700 g water has 70% hydration. The hydration level is the single most consequential variable in bread making after flour choice: it governs how open the crumb will be, how sticky the dough is to handle, how quickly fermentation gases expand the gluten network, and what crust character the finished loaf develops. At the low end — below 60% — doughs are stiff, easy to shape, and produce tight, chewy crumbs suited to bagels, pretzels, and dense country loaves. As hydration climbs toward 70–75%, the dough becomes more extensible and produces the open, irregular crumb associated with sourdough batards and baguettes. Above 80%, the dough is slack and wet, requires careful stretch-and-fold handling (traditional kneading is nearly impossible), and can produce highly open, almost translucent crumbs in skilled hands — hallmarks of ciabatta (typically 80–85%) and Tartine-style country bread. Beyond 90% the dough is closer to a thick batter and is handled exclusively with proofing baskets, scrapers, and minimal manipulation. Hydration interacts with protein content: higher-protein bread flour (13%+) can absorb and hold more water than all-purpose flour (10–11%), and whole-grain flours absorb water more slowly because bran particles continue hydrating for 20–30 minutes after mixing. Temperature, humidity, and specific flour mill grinding also influence effective hydration. Because of these variables, professional bakers typically hold back a portion of formula water (see bassinage) and adjust to feel and visual cues rather than adding every calculated drop.

In use

“She bumped the hydration from 72% to 78% and immediately noticed the dough required four sets of stretch-and-folds rather than two to build enough structure for shaping.”

Related terms

Baker's Percentage BassinageStretch and FoldCiabattaCrumb StructureBranGluten WindowDDT (Desired Dough Temperature)

References

1.Tartine Bread — Chad Robertson (Chronicle Books, 2010)
2.Advanced Bread and Pastry — Michel Suas (Delmar, 2009)
3.Modernist Bread — Nathan Myhrvold & Francisco Migoya (The Cooking Lab, 2017)
4.The Perfect Loaf — Maurizio Leo (Clarkson Potter, 2022)

Confidence: high

Notes

Effective vs. formula hydration

Formula hydration counts only the water intentionally added. Effective hydration (sometimes called 'total water') also accounts for water contributed by eggs, milk, honey, and sourdough starter — a more accurate picture of how wet the dough truly is. A brioche formula may show 40% water by formula but have 60%+ effective hydration once egg yolks, whole eggs, and milk are included.

Flour type and absorption

Different flours absorb water at different rates and capacities. Whole wheat and rye absorb substantially more water than white flour, and their bran particles can continue absorbing during the first 30 minutes of mixing, causing what initially feels like a slack dough to tighten considerably. Highly refined patent flour absorbs less than high-extraction flour. Bakers new to a new flour batch should always test a small quantity first and adjust hydration accordingly.

Hydration and crust character

Higher-hydration doughs generate more steam during the first minutes in the oven, which delays crust set and allows greater oven spring, often producing blistered, shatteringly crisp crusts. Very low hydration doughs develop a harder, drier crust more quickly, which can limit final volume but is desirable in some styles.