🍞SourdoughCalc
The Next-Gen Sourdough Baker's Engine

True Total Hydration & Dough Rheology Calculator

Stop baking slack, collapsed bread. Eliminate the hidden +3% water surge from active levain, calculate multi-flour absorption limits, and solve hot-weather fermentation with DDT crushed ice thermodynamics.

V0.1.0 Artisan EngineZero Server Latency • True Hydration Corrected

Artisan Sourdough Hydration & Rheology Calculator

Standard Banneton Sizes
units
grams
Target Water Hydration

Water percentage added to main dough

70%Recomm: 68.8%
60% (Stiff Bagel)70% (Classic Loaf)78% (Open Crumb)85%+ (Ciabatta/Extreme)
Active Levain (Starter)20%
Standard: 20% (100g per 500g flour)
Fine Sea Salt2.0%
Standard: 2.0% (Tightens gluten mesh)
RHEOLOGY MASTER METRICPhysics Corrected
72.7%
True Total HydrationApparent: 70%
Starter adds moisture: Your levain supplies 47g water and 47g flour, elevating true dough hydration by +2.7%.
Ingredient ChecklistBatch Total: 900g
Main Dough Flour100.0% Baker's
469g
• Bread Flour (80%)375g
• Whole Wheat Flour (15%)70g
• Dark Rye Flour (5%)23g
Main Added Water69.9%
328g
• Autolyse Water (90%)295g
• Bassinage Water (Reserved w/ Salt)33g
Active Levain (Starter)20.0%
(47g flour + 47g water)
94g
Fine Sea Salt2.0%
(2.0% salinity)
9.4g
100% r/Sourdough Rule 5 Compliant
Dough Rheology Whitepaper

Why 80% of Sourdough Recipes Collapse at High Hydration

Read full mathematical proof

The Fatal Blindspot of "Apparent Hydration"

When a legacy calculator asks for 450g of flour and 315g of water, it records your hydration as 70.0%. It treats the subsequent addition of 100g of active levain as an inert afterthought.

However, standard 100% hydration levain is exactly 50g of flour and 50g of water. The moment you fold your starter into the autolysed dough, your real system totals become:

Total System Flour:450g + 50g = 500g
Total System Water:315g + 50g = 365g
True Total Hydration:365 / 500 = 73.0% (+3.0%)

The Biochemical Consequence

In artisanal bread making, hydration does not follow a linear sensory curve. Passing 72% hydration with standard grocery bread flour exceeds the molecular holding capacity of the glutenin proteins:

  • Free Water Pool: The excess 3% exists as unbound free water, lubricating the gluten chains and causing lateral dough spreading (puddling) upon turn-out.
  • Accelerated Proteolysis: Higher moisture accelerates bacterial protease motility, breaking down the peptide bridges before oven spring can take hold.
  • SourdoughCalc Fix: Our algorithm reverse-calculates from raw dough weight, isolating starter flour from main flour to lock your target hydration with surgical precision.

Flour Absorption & Rheology Comparison Matrix

Empirical holding capacity and gluten elasticity ceilings across common milling standards

Lab Tested & Rheometer Verified
Flour VarietyProtein %Primary Absorption MechanismBaseline Hydr.Max Hydro-CeilingStandard Brand Benchmarks
Hard Red Bread Flour12.7% - 14.0%High glutenin-to-gliadin ratio; dense disulfide bond cross-linking65% - 72%82%King Arthur Bread Flour, Central Milling Artisan Craft
Stoneground Whole Wheat13.5% - 14.5%Insoluble dietary fiber & bran pericarp micro-sponge absorption80% - 85%92%Bob's Red Mill Organic Whole Wheat, King Arthur Traditional Whole Wheat
Dark Rye Flour (Type 1740)9.0% - 11.5%Arabinoxylans (pentosans) forming high-viscosity hydrocolloids90% - 100%110%Hodgson Mill Dark Rye, Bob's Red Mill Dark Rye
Unbleached All-Purpose10.5% - 11.7%Moderate gluten matrix; prone to proteolytic slackening if over-hydrated60% - 66%72%King Arthur Unbleached AP, Gold Medal Better for Bread
Whole Spelt (Triticum spelta)13.0% - 14.5%High gliadin (high extensibility, lower elasticity); absorbs quickly but slackens64% - 70%76%Arrowhead Mills Organic Spelt, Bob's Red Mill
Durum Semolina Rimacinata12.0% - 13.5%Coarse crystalline endosperm; yellow carotenoid pigments with steady water uptake68% - 74%80%Caputo Semola Rimacinata, Molino Grassi
Pro Baker’s Rule of Thumb: When increasing whole wheat or dark rye in your dough formula above 20%, increase total autolyse water by 1.25x the whole grain proportion to prevent the coarse bran flakes from robbing moisture from the gluten network.
Baker's ArsenalTested & Recommended Gear

The Artisan Baker's Essential Hardware Toolkit

Reliable sourdough starts with accurate hydration math, but finishes with thermal steam retention and knife-edge scoring. Here is the verified hardware standard.

View Starter Kit on Amazon
Must-Have$69.90

Lodge 5-Quart Double Dutch Oven

Cast iron steam trap. Shallow base allows effortless dough loading without burning wrists.

Check on Amazon
Popular$24.95

Artisan Banneton Proofing Baskets (2-Pack w/ Liners)

100% natural Indonesian cane. Wicks moisture from surface skin to guarantee blistering and sharp ears.

Check on Amazon
Essential$14.50

UFO Artisan Bread Lame w/ 5 Razor Blades

Precision circular grip for shallow 30-degree undercut scoring on high-hydration dough.

Check on Amazon
Accuracy$19.99

0.1g Precision Micro-Kitchen Scale

Crucial for weighing 2.0% salt and levain accurately. Standard 1g kitchen scales miss micro-fractions.

Check on Amazon
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Artisan Baker's Library

Deep-Dive Masterclasses on Bread Rheology

View all 7 guides
2026-09-187 min read

The Science of True Total Hydration: Why Your Starter's Water Content Matters

Most bakers believe they are baking at 70% hydration, only to find their dough slack, sticky, and unable to hold tension. The culprit is 'Apparent Hydration'—the amateur omission of the water already contained within your starter.

Read Masterclass
2026-09-188 min read

King Arthur vs. Bob's Red Mill vs. Bread Flour: Absorption Limits Tested

Not all flours absorb water equally. A blend with 15% Whole Wheat and 5% Dark Rye behaves radically differently than pure unbleached bread flour. Here are the lab-tested absorption benchmarks.

Read Masterclass
2026-09-186 min read

Autolyse vs. Fermentolyse: When and Why to Hold Back Your Levain

Invented by Professor Raymond Calvel, the autolyse stage hydrates starch and activates amylase without acid-induced gluten tightening. Here is when to use pure autolyse versus fermentolyse.

Read Masterclass
2026-09-189 min read

The DDT Masterclass: How to Control Fermentation Speed Using Ice Water Calculations

Temperature is your recipe's most potent ingredient. An increase of just 5°F doubles fermentation kinetics. Learn how professional bakers use thermodynamic ice calculations to guarantee consistent 76°F bulk fermentation.

Read Masterclass
2026-09-187 min read

Why Your 80% Hydration Dough is a Sticky Mess: 5 Structural Failures and Fixes

Social media has convinced home bakers that 80%+ hydration is the only hallmark of artisan mastery. In reality, high hydration without gluten development leads to flat, gummy frisbees.

Read Masterclass
2026-09-186 min read

Baker's Math Demystified: How to Scale Any Bread Recipe from 1 to 10 Loaves

In Baker's Math, total flour is always 100%. Master this simple universal language of commercial baking to scale recipes from a single loaf to an entire commercial production run.

Read Masterclass

Frequently Asked Rheology & Hydration Questions

Common mechanical pitfalls, starter moisture dynamics, and temperature management

What is the difference between Apparent Hydration and True Total Hydration?

Apparent hydration only considers the water directly poured into the mixing bowl divided by the main flour weight. True Total Hydration accounts for the water and flour inside your active starter. Since standard starter is 50% water, your actual dough is consistently 2.7% to 3.0% wetter than apparent formulas indicate.

Why should I use crushed ice in my water during summer bakes?

Wild yeasts double twice as fast when room temperature climbs over 80°F (27°C). To prevent dough from overproofing and turning sour/gummy, you need water colder than tap water. Crushed ice absorbs 80 cal/g of heat during phase change, safely dropping dough temperature to the optimal 76°F DDT without changing hydration ratios.

Can I substitute All-Purpose flour 1:1 for Bread Flour?

No. All-Purpose flour has 10.5% to 11.5% protein and a maximum safe hydration ceiling of 68-70%. Bread flour (12.7% to 14.0% protein) can easily support 75-80% hydration. If using All-Purpose flour, reduce target hydration in SourdoughCalc to 64-66% to prevent dough slackening.

Why does SourdoughCalc split water into Autolyse and Bassinage?

Holding back 10% of recipe water (the French *bassinage* method) allows full enzymatic hydration of the flour during initial autolyse. The reserved water is later used to dissolve the salt, ensuring even dispersion without dehydrating the gluten network prematurely.