Sourdough hydration calculator

The “Secret Sauce” of Open Crumb: Why Your Sourdough Recipe is Lying to You

There is a moment in every baker’s journey that separates the novices from the artisans.

It isn’t when you buy your first banneton. It isn’t when you name your starter (though “Dough Parton” is a classic). It is the moment you stop looking at cups and spoons, and start looking at Percentages.

Specifically, Hydration Percentage.

If you have ever followed a recipe perfectly, only to end up with a dough that feels like brick mortar—or worse, a puddle of soup that refuses to hold its shape—the problem wasn’t your technique. The problem was the math.

Most cookbooks simplify recipes. They tell you to use 500g of flour and 350g of water. They tell you to add 100g of starter. But they fail to mention the most critical variable: The flour and water inside your starter counts.

If you ignore the starter’s composition, your hydration calculation is wrong. And in sourdough, being off by 3% is the difference between a glorious, open-crumb masterpiece and a dense, gummy frisbee.

We built the Sourdough Hydration Calculator (above) to fix this. It is the tool professional bakers use to engineer the perfect loaf, stripping away the guesswork and giving you total control over your dough.

What is Baker’s Math? (And Why You Need It)

In baking, everything is relative to the flour.

The total flour in a recipe is always 100%. Every other ingredient—water, salt, starter—is calculated as a percentage of that flour weight.

The Golden Formula:

$$\text{Hydration \%} = \left( \frac{\text{Total Water}}{\text{Total Flour}} \right) \times 100$$

This seems simple until you add the starter. A standard starter is 100% hydration (equal parts flour and water). So, if you add 100g of starter, you are actually adding 50g of flour and 50g of water to your dough.

Our calculator automatically extracts these hidden values to give you your True Hydration.

The Hydration Spectrum: Finding Your Sweet Spot

Using the calculator, you can dial in the exact texture you want. Here is what the numbers mean:

1. The Safety Zone (60% – 68%)

• Texture: Firm, tacky but not sticky. Easy to knead by hand.
• Result: A tight, uniform crumb. Great for sandwich bread and toast.
• Verdict: Perfect for beginners. If you are new, aim for 65%.

2. The Artisan Standard (70% – 75%)

• Texture: Sticky. Requires “Slap and Fold” or wet hands to handle.
• Result: The classic “Tartine” style. Crisp blistered crust, open irregular holes, and a chewy texture.
• Verdict: The goal for most home bakers. Aim for 72%.

3. The Danger Zone (78% – 85%+)

• Texture: A living creature. It will try to escape the bowl. It requires coil folds and gentle handling.
• Result: Ciabatta-style crumb. massive air pockets (alveoli), very soft interior.
• Verdict: High risk, high reward. If your gluten structure isn’t perfect, this turns into a pancake.

How to Use the Calculator

This tool acts as your recipe development lab.

Step 1: The Base Recipe (Tab 1)

Enter the flour and water you intend to use.

• Pro Tip: If you are using whole wheat or rye, you generally need higher hydration because these flours are thirstier than white flour.

Step 2: The Starter Variable (Tab 2)

Enter your starter amount.

• The Slider: Most people keep their starter at 100% hydration (feed it 1:1:1). But if you keep a stiff starter (more flour than water), slide the hydration down to 50% or 60%. The calculator adjusts the math instantly.

Step 3: The Adjustments (Tab 3)

• Salt: Never forget salt. 2% is the industry standard for flavor and fermentation control.
• Add-ins: Olive oil, honey, or milk contain water. Enter them here to see how they impact the wetness of the dough.

Troubleshooting: “Why is my dough wet?”

If the calculator says you are at 70% hydration, but your dough feels like soup, check your flour.

• Protein Content: Low protein flour (All-Purpose) cannot hold as much water as Strong Bread Flour.
• The Fix: If using AP flour, drop your target hydration by 2-3%. Use the calculator to reduce the water until you hit 67%.

The Verdict

Baking is science for hungry people. You can’t cheat the chemistry, but you can master it.

Stop guessing. Stop pouring in extra flour by eye and ruining your ratios. Use the Sourdough Hydration Calculator to engineer your recipe, and finally get that ear you’ve been dreaming of.