Dough hydration explained

The hydration formula

Hydration is a baker’s percentage: flour is always 100%, and every other ingredient is written as a share of the flour weight. Weigh both flour and water in grams, because the maths only works by weight.

Hydration (%) = water (g) ÷ flour (g) × 100

Turn it around when you know the hydration you want: Water (g) = flour (g) × hydration (%) ÷ 100.

Worked examples in grams

• Check a recipe: 500 g flour and 325 g water. 325 ÷ 500 × 100 = 65%.
• Hit a target: 1,000 g flour at 70% needs 1,000 × 70 ÷ 100 = 700 g water.
• Several flours: add them together first. 400 g bread flour, 100 g wholemeal flour and 380 g water: 380 ÷ 500 × 100 = 76%.
• Start from dough weight: four 250 g pizza balls make 1,000 g of dough. At 62% water, 3% salt and 0.2% yeast the percentages add up to 165.2%, so flour = 1,000 × 100 ÷ 165.2 = 605 g. Water is then 605 × 62 ÷ 100 = 375 g, with 18 g salt and 1.2 g yeast. The pizza dough calculator does this for any number of balls.

If a recipe gives flour or milk in cups, convert them to grams with the ingredient weight chart before you work out hydration.

What counts as liquid

Besides water, King Arthur Baking counts milk, juice, tea, coffee, beer and wine as water when it states hydration. That is a useful shortcut rather than an exact figure: cow’s milk is about 87% water (the University of Guelph’s dairy science text gives 87.3%), so counting it in full slightly overstates hydration. A dough of 500 g flour and 300 g whole milk reads as 60%, but the milk holds about 262 g water, which is 52%.

Eggs and butter are usually left out of the hydration figure, yet they still bring water to the dough. King Arthur puts eggs at roughly 75% water and butter at around 18%; Oklahoma State University Extension notes that the Codex standard allows butter at most 16% water. This is why an enriched dough such as brioche can have a low stated hydration and still feel soft.

How starter and preferments count

A sourdough starter, levain, poolish or biga is flour and water (with yeast or a wild culture) mixed ahead of time, so part of the recipe’s flour and water is already inside it. Its own hydration tells you how to split it:

Starter flour (g) = starter (g) ÷ (1 + starter hydration ÷ 100)
Starter water (g) = starter (g) − starter flour (g)

Worked example: a 100% hydration starter

A 100% hydration starter holds equal weights of flour and water, so 100 g contains 50 g flour and 50 g water. Take a dough of 450 g flour, 315 g water, 100 g of that starter and 9 g salt:

• Final dough only: 315 ÷ 450 × 100 = 70%.
• Overall, including the starter: (315 + 50) ÷ (450 + 50) × 100 = 365 ÷ 500 × 100 = 73%.
• Prefermented flour: 50 ÷ 500 × 100 = 10% of the total flour.

A stiff starter splits differently: 150 g at 50% hydration is 150 ÷ 1.5 = 100 g flour and 50 g water.

Final dough or overall formula: two ways to count

Final dough: percentages use only the flour added at the final mix, and the starter or preferment appears as one ingredient. Overall formula: the preferment is split into its flour and water, and every percentage uses the total flour. The Bread Bakers Guild of America’s formula layout standard uses the overall formula and records the share of prefermented flour separately.

The gap can be large. King Arthur Baking’s professional reference shows one poolish French bread both ways: water is 48% of the final-dough flour, but 65% of the total flour once the poolish is counted. Most sourdough writers quote the overall number and count the flour and water in the starter or levain: King Arthur’s home sourdough example reaches 77% this way. The small amount of ripe starter used to seed a levain is often left out, as it is by The Perfect Loaf and in King Arthur’s professional sourdough baguette formula. Two recipes that both say 75% may not match, so check the convention and state your own. The baker’s percentage calculator shows both figures, and the guide to poolish, biga and levain explains how each preferment is built.

Typical hydration by bread and pizza style

These are starting points from published formulas, counted on the overall formula. Your flour can move the right number by several points.

Neapolitan figures differ by source. Within the AVPN’s 55.6–62.5%, the right point depends on how much water the flour absorbs. The EU’s 2010 Pizza Napoletana TSG specification names 1 litre of water and 1.8 kg flour, about 56%. Ooni describes Neapolitan-style dough as generally 60–65%, and Modernist Cuisine’s own Neapolitan dough is 62.3%. If you call a recipe AVPN style, keep it inside the AVPN range.

Flour, absorption and experience

The right hydration depends on how much water your flour can absorb. Absorption is usually measured with a farinograph, and BAKERpedia explains that it rises with protein, damaged starch and pentosans (a type of fibre). The AVPN even specifies flour with 55–62% absorption, almost the same band as its dough range.

• Protein: higher-protein bread flours (about 12–14%) generally take more water than lower-protein flours. The Perfect Loaf notes that softer flours common in the UK and Europe may need less water to stay manageable.
• Wholegrain: wholemeal and other wholegrain flours absorb more water. King Arthur notes that at the same 75%, a whole wheat dough feels firmer than an all-purpose one.
• Experience: with all-purpose flour, King Arthur describes 55–65% as firm and 75–85% as slack and sticky. Wetter doughs need folding and gentle shaping rather than kneading, so raise hydration a few points at a time as your handling improves.

Quick troubleshooting

• Too sticky or soupy: check that you counted every liquid, including the starter. Build strength with folds and give the dough time, because a slack dough often firms up as it rests. Next time, hold back about 10% of the water and add it only if the dough can take it. Add flour only as a last resort, since it changes every percentage in the recipe.
• Too stiff or tight: if the dough resists stretching or shows dry flour, add water a splash at a time. Wholegrain and high-protein flours often need more water than the recipe’s flour did.
• Spreads flat or bakes gummy: the dough may hold more water than your flour can support. Lower the hydration a few points or use a stronger flour.

Keep your dough recipes in CookBook

CookBook saves bread and pizza recipes from websites, social posts, photos and cookbooks, and keeps them organised in one place. In cooking mode you can change servings and the measurement system: ingredient amounts scale, but times in the method do not, so keep judging fermentation by the dough. See how to add, import and create recipes.

Sources

• King Arthur Baking: Baker’s percentage (professional reference)
• King Arthur Baking: Hydration in bread dough, explained
• King Arthur Baking: When it comes to bread dough, is wetter really better?
• King Arthur Baking: 5 tips for working with high-hydration doughs
• King Arthur Baking: The 5 elements of great bagels
• King Arthur Baking: How can I get a more bubbly, open crumb in my focaccia?
• King Arthur Baking: French Bread with Poolish (professional formula)
• King Arthur Baking: Ciabatta (professional formula)
• King Arthur Baking: Sourdough Baguettes (professional formula)
• BAKERpedia: Water absorption
• BAKERpedia: White pan bread
• BAKERpedia: How does dough absorb water?
• Bread Bakers Guild of America: Formula layout standards, part I (Bread Lines, 2009)
• Associazione Verace Pizza Napoletana: Disciplinare 2024 (English)
• EUR-Lex: Commission Regulation (EU) No 97/2010, Pizza Napoletana TSG
• Modernist Cuisine: Understanding Neapolitan pizza
• Ooni: Pizza dough hydration explained
• Pizza Today: NY-Style Pizza Dough
• PizzaMaking.com: New York style pizza crust (formula by Tom Lehmann, American Institute of Baking)
• The Perfect Loaf: What is dough hydration?
• University of Guelph: Dairy Science and Technology, composition and structure overview
• Oklahoma State University Extension: Butter, chemical and physical properties and health effects (FAPC-253)