Sourdough Hydration Explained

Whether you're just starting out on your sourdough journey or looking to up your skills and learn about the science behind sourdough baking, understanding hydration is a must. In this article, we'll delve into the ins and outs of sourdough hydration, why it matters, and how it can transform your bread baking adventures. Let's get started!

Jump to:

• What Does Sourdough Hydration Mean?
• The Formula: How To Calculate Sourdough Hydration?
• How Does The Level Of Hydration Affect Sourdough?
• So What Is  A Good Hydration Percentage for Sourdough Bread?
• Sourdough Hydration and Type Of Flour
• What Does 100% Hydration Sourdough Starter Mean?
• Sourdough Hydration FAQs
• More Sourdough Resources

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What Does Sourdough Hydration Mean?

So, what exactly is sourdough hydration? In simple terms, it's all about how much water you mix with your flour to make your dough. Think of it as the dough's water content (which includes water in your sourdough starter as well as extra water you add to the dough). 

Hydration is expressed as a ratio of water to flour. For example, if your dough is 70% hydration, that means you've got 70 grams of water for every 100 grams of flour.

The higher the hydration, the wetter and stickier the dough will be (for example Sourdough Fougasse or Sourdough Ciabatta). This ratio is crucial because it influences everything from the handling to the dough's texture to how it bakes. 

Understanding hydration helps you control your dough better, leading to more consistent and delicious results.

The Formula: How To Calculate Sourdough Hydration?

Calculating sourdough hydration might sound tricky, but it's actually pretty simple! Here's the basic formula:

Hydration (%) = (Total Water / Total Flour) x 100

To break it down, you'll need to know the total amount of flour and the total water in your recipe. This includes the flour and water in your starter as well.

Let's go through an example together. Say you're using:

• 160g of 100% hydration starter (this means equal parts flour and water: 80g flour + 80g water)
• 400g of flour
• 240ml (or grams) of water

STEP 1. First, calculate the total weight of flour:

•  Flour in starter: 80g
•  Additional flour: 400g
•  Total flour: 80g + 400g = 480g

STEP 2. Next, calculate the water amount:

•   Water in starter: 80g
•   Additional water: 240g
•   Total water: 80g + 240g = 320g

STEP 3. Now, use the hydration formula:

• Hydration (%) = (320g / 480g) x 100
• Hydration = 0.6667 x 100
• Hydration = 66.67%

Or, to use the formula above: 

Hydration (%) = (Total Water / Total Flour) x 100 = (( 80 + 240 ) / 80 + 400 ) x 100 = 66.67%

So, in this example, your dough has a hydration level of 66.67%. Easy, right? This percentage tells you how wet or dry your dough will be, and it's a handy way to tweak recipes to get the perfect loaf.

How Does The Level Of Hydration Affect Sourdough?

It's a common misconception that hydration only affects how sticky the dough is and how easy it is to handle. In reality, hydration level influences every stage of sourdough baking, from bulk fermentation to the final crumb texture.

Bulk Fermentation

Hydration level plays a crucial role during Bulk Fermentation, also known as the first rise of your dough. A higher hydration dough ferments more quickly, especially at room temperature because the increased water content encourages yeast activity and enzyme action. This can lead to a shorter bulk fermentation time.

As a result, you need to keep an eye on your high-hydration doughs to avoid overfermenting. 

Additionally, the extra water aids in gluten development, making the dough more extensible (although it also depends on the flour P/L ratio) and allowing it to rise more easily. However, too much hydration can weaken the dough structure, so finding the right balance is key. 

Keep an eye on your dough during bulk fermentation to ensure it's rising well and developing that strong, stretchy gluten network.

Handling and Folding Techniques

When it comes to handling and folding sourdough, hydration level makes a big difference.

With wetter dough, you'll notice it can be a lot stickier and more challenging to manage, and that's why many beginners start with low-hydration dough and increase the total weight of water in the dough gradually, as they develop their dough handling skills. 

One popular method that is brilliant when handling higher-hydration sourdough is the coil fold technique. This is used in place of the stretch and fold method. To do this, use cold wet hands to prevent sticking. Gently lift the edge of the dough, stretch it upwards, and then fold it over itself (see video below).

Repeat this process from different sides of the dough.

Shaping

Shaping your sourdough is where you give your dough its final form before baking, and hydration level plays a crucial role here, especially for higher hydration sourdough bread. The ultimate goal is to create a well-shaped loaf that will rise beautifully in the oven.

Due to its moisture content, a higher hydration level can make the bread dough more challenging to handle and shape. It tends to spread out more and can stick to surfaces like your banneton basket. This becomes a real problem when you try to turn the dough out of the proofing basket.

It is such a disappointment after you've put in all the work into baking a beautiful dough. 

To combat this, make sure to flour your banneton basket generously. We recommend using rice flour for dusting, as it has a finer texture and helps prevent sticking a lot better than regular flour.

When shaping, handle the dough gently and confidently, using a technique that works best for you. The goal is to create surface tension and a smooth shape, which helps the dough hold its form during baking and results in a better rise and crumb structure.

If sourdough shaping is not the skill that you have mastered, but want to give high-hydration dough a try, consider baking sourdough in a loaf pan. The support of the pan will prevent the dough from spreading!

Baking

The hydration level of your dough significantly impacts the baking process and the final outcome of your loaf. Here's how hydration level affects the baking of sourdough:

• Oven Spring: A higher hydration dough tends to have more oven spring, meaning it expands more dramatically in the oven. This is due to the steam created from the extra water evaporating during baking, which helps the dough rise and creates a lighter, airier crumb.
• Crust Formation: Higher hydration doughs often result in a thinner, but crispier crust due to the increased moisture content. Learn more about how to make sourdough crust thinner and softer!
• Baking Time and Temperature: The hydration level can also affect baking time and temperature. Higher hydration doughs may require slightly longer baking times to ensure the interior is fully baked while maintaining a golden crust. They may also benefit from starting with an even higher oven temperature to encourage initial rise and crust formation.
• Steam and Moisture: Managing steam is crucial when baking high-hydration sourdough. Covering the dough during the initial baking phase traps steam, which helps with oven spring and crust development. If you do not have a Dutch Oven to capture the steam, you are likely to get a better oven spring with high hydration doughs, as it releases more steam into the oven as it bakes!

Crumb Texture

The crumb texture of your sourdough loaf is heavily influenced by its hydration level. A higher hydration sourdough tends to result in a more open crumb, characterized by larger air pockets and a lighter, airy texture.

This is because the additional water helps create a dough that is easier for gas bubbles to expand within during fermentation and baking.

So What Is  A Good Hydration Percentage for Sourdough Bread?

If you're just starting out with sourdough baking, it's often recommended to begin with a lower hydration dough. This means using a lower hydration level, typically around 60% to 65%. This range is more forgiving and easier to handle, making it ideal for beginners aiming to bake delicious sourdough bread without feeling overwhelmed. 

As you gain experience and confidence in your baking skills, you can gradually increase the hydration level. Many advanced bakers enjoy working with high hydration sourdough bread recipes, which can range from 75% to 85% hydration or even higher. These doughs require more precise handling techniques but can yield loaves with a more open crumb and complex flavours.

Ultimately, the best hydration percentage for your sourdough bread depends on your personal preference and the specific recipe you're using (type of flour, mix-ins etc will affect the hydration percentage). 

Experiment with different hydration levels to find what works best for you. Starting with a low hydration recipe allows you to master the basics before venturing into higher hydration baking adventures.

Sourdough Hydration and Type Of Flour

The type of flour you use in your sourdough baking greatly influences the hydration levels you'll work with and the final outcome of your loaf. Learn more in our article about Water Absorption Capacity in Flour For Sourdough Bread.

Here's a breakdown of how different flours affect hydration:

• White Flour has less bran and germ than whole wheat or whole-grain flours, so it absorbs less water. You can use a lower hydration level when baking with white flour compared to whole wheat or whole-grain flours. But high-protein white flour absorbs water better, so you can increase hydration alongside protein content (like we do in our 80% Hydration Sourdough Bread recipe).
• Whole Wheat Flour absorbs more water than white flour due to its higher fibre content. It typically requires a higher hydration level to achieve the same dough consistency as white flour. Start with a slightly higher water-to-flour ratio when using whole wheat flour in your sourdough recipes. And try our 100% wholemeal sourdough bread recipe!
• Whole-Grain Flour. Similar to whole wheat flour, whole-grain flours (such as rye or barley (Barley Sourdough recipe HERE) absorb more water than white flour. They contain more bran and germ, which absorb water during mixing. Adjust your hydration level accordingly, starting with a higher ratio of water to flour compared to white flour.
• Spelt Flour. Spelt is known for its extensibility, and works better with a little less water (try our Spelt Sourdough Bread Recipe to test it).

A Note on Protein Content

The protein content of flour, which determines its gluten-forming potential, also affects hydration. Higher protein flours (like bread flour) absorb more water and can handle higher hydration levels, resulting in a stronger gluten network and better structure.

What Does 100% Hydration Sourdough Starter Mean?

In sourdough baking, the term "100% hydration sourdough starter" refers to a starter that is maintained with equal parts water and equal amounts of flour. This means for every weight of flour you use, you add an equal weight of water to your starter.

The majority of the recipes you'll encounter will specify using a 100% hydration starter. This consistency makes it easier to calculate and adjust hydration levels in your dough, ensuring more predictable and consistent results.

Some bakers prefer to maintain a stiff starter, which has a lower hydration level - typically around 60% to 80%. This means the starter contains less water compared to flour. Reasons for keeping and using a stiff starter include:

• Less Frequent Feeding: Stiff starters tend to ferment more slowly and can go longer between feedings, making them more manageable for bakers who bake less frequently.
• Flavour Development: A stiff starter may contribute to different flavour profiles in your sourdough bread, as fermentation occurs at a slower rate.
• Texture and Handling: Stiff starters are firmer and less sticky, which can make them easier to handle and incorporate into the dough.

Sourdough Hydration FAQs

More Sourdough Resources

• How To Feed Sourdough Starter (Feeding and Maintaining Tips)
• Beginner's Guide to Sourdough Autolyse: What, How & Why?
• When is Sourdough Bread Done Proofing and Ready to Bake?
• Delicious Recipes Using Active Sourdough Starter

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Discovering the world of sourdough hydration is key to mastering delicious bread baking. From understanding hydration basics and calculating ratios to exploring how hydration affects every stage of baking, this guide helps beginners and seasoned bakers alike achieve the perfect loaf. Learn to adjust hydration levels, choose the right flours, and optimize your sourdough starter for baking success.