Sourdough Hydration Explained (What, Why, How & When)


Initially, following a few tutorials may get you producing some pretty decent sourdough bread. But eventually you will no doubt come across hydration levels, especially when it comes to the effect it has on sourdough. Once I understood the basic principles, I was well on my way to becoming a better baker

What does sourdough hydration mean and how does it affect bread? The hydration level of bread is measured in percentage. It is a calculation of how much water the dough contains, in relation to how much flour it has. In general, sourdough bread tends to have hydration levels from 65% to 100% depending on the type of flour used. The higher the hydration level, the more open the crumb texture, and the thinner and crisper the crust.

Once you understand hydration levels, and how to adjust your hydration to get certain outcomes for your bread, it can be a real game changer. But it can be a little tricky to grasp at first. Let’s break it down and get into a little more detail…

What is Sourdough Hydration?

As mentioned earlier, when we say hydration level of bread, we are talking about ‘how much water/liquid is in the dough’. The higher the water or liquid content, the higher the hydration percentage. But how does the hydration level of sourdough affect you as a bread baker?

In this post I’ll take you through explanations of:

  • Why it’s important to know about hydration in your dough.
  • How you can use hydration calculations to affect the crumb, texture and crust of your bread.
  • How to calculate hydration levels for sourdough.
  • The ideal hydration level for sourdough bread.
  • Useful tips when working with higher hydration sourdough bread.

Why are Hydration Levels Important in Sourdough Baking?

The hydration level of your dough has a pretty big impact on the type of bread you end up with. In fact, I would say it is the biggest factor in determining the texture and look of your bread. It will also give you a big indication of how the dough is going to behave during mixing, fermenting and shaping.

Due to the nature of how sourdough ferments, there is a tendency for the crumb to be quite tight. So sourdough breads are usually made with wetter doughs than other yeasted homemade breads. So it’s important to understand how hydration affects the dough so that you can find the ideal hydration level for you to work with.

How Lower Hydration Levels Affect Dough

The lower the hydration, the stiffer the dough. And for you as a baker it will mean the following:

  • You have to work harder to incorporate all the ingredients.
  • It will take longer for the gluten to develop (hence may require more kneading).
  • The fermentation time will be longer.
  • The dough will be less sticky and much easier to handle.

How Higher Hydration Levels Affect Dough

The higher the hydration, the more slack and soft the dough will be. It will mean:

Wetter dough is harder to handle
  • Ingredients will be more easily incorporated as the dough will be wetter.
  • The dough will be stickier and harder to handle.
  • The dough will be more slack, so it’ll be harder to shape. (In addition, extra steps may be needed to develop enough dough strength so that it can rise well).
  • Kneading is less important, and perhaps not needed at all. This is because the extra wetness allowing the yeasts and bacteria to move around more easily, making it better able to ferment and develop gluten.
  • The dough will tend to ferment faster and need less rising time.

So the main take away around working with higher hydration dough, is that it is more difficult to handle due to the stickiness and slackness. And it requires more skill to handle and shape. (Tips below on working with high hydration dough).

As a beginner sourdough bread baker, it’s best to start off working with lower hydration dough, and then increase the hydration gradually as your experience with handling dough grows. But why bother if it’s more difficult? Well, higher hydration dough brings about some benefits…

How Hydration Levels Affect Bread

As I mentioned earlier, hydration levels affect not just your dough, but the end result of your bread. Here are some of the ways your bread can be affected if you were to increase the hydration level in your recipe:

  • Texture – The higher the hydration level of your bread, the softer the texture will be, and the more open the crumb will be (i.e. bigger holes inside).
  • Crust – Sourdough bread crust tends to be quite thick and hard, but a higher hydration sourdough has a thinner crust that stays crispy for longer.
  • Flavor – Higher hydration loaves tend to have a more developed flavor of mild sourness, whereas lower hydration gives a more pronounced ‘vinegary’ sourness.
  • Appearance – The higher the hydration of your loaf, the less amount it is likely to rise because the dough is a lot slacker. (You can choose to bake it in a loaf tin if you wish for a taller loaf that still has the benefits of a high hydration bread).

Taking into consideration all of the above, most people find it is worth the effort of learning to work with higher hydration dough. You get a better tasting bread, with a thinner crispier crust and a softer textured, more open crumb bread.

What’s A Good Hydration Level to Aim for?

This is one of those ‘it depends’ kind of answers. As mentioned earlier, the higher the hydration, the more difficult it is to handle and shape the dough. But you are rewarded with a more open crumb and thinner crust.

How high a hydration level you go is going to be dependent on the eater’s preferences. It’s a delicate balance of how to handle the dough, and how open a crumb is perfect for you. You may find that for a sandwich style bread, you prefer a lower hydration, in order to allow for a sandwich with fillings to hold better. And a higher hydration bread as a condiment to soup for example.

Different breads have different hydration levels

To give you an idea of the kind of texture different hydration levels can give, here’s a range of bread products and what kind of hydration levels they usually range between:

Hydration
Level
Affect on
Dough
Affect on
Bread
Common
Breads at this
Hydration
50% – 60%Firm,
Not sticky,
Easy to handle
Tight Crumb, firmer texture, rises tallBagels,
Pretzels
60% – 70%Slightly sticky/tacky,
Standard dough texture
Medium Crumb,
softer texture
Sandwich bread,
Challah,
French bread,
Basic sourdough
70% or moreLoose, slack & sticky,
Harder to handle/shape
Very open crumb,
thin crust, flatter loaf
Ciabatta,
Focaccia,
Whole grain sourdough,
Artisan sourdough

Hydration Levels and Types of Flour

In addition to the type of crumb you are after, the type of of flour you use will have an impact on how high a hydration level you want. Whole grains soak up more water, so the more you have in your dough, the higher the hydration level you can afford to have.

As a basic rule of thumb, if you are switching to whole wheat completely from white, you should aim to add 10 to 15% higher hydration to allow for the extra absorbency.

But individual flours vary in absorbency levels. These variations are even present for the same type of flour, but of different brand. This is why it’s important to test out and get used to the same type of flour consistently, before venturing out to chop and change the flours you are using.

It’s also a common reason beginner’s get stuck when trying to follow a recipe and the dough doesn’t look or behave anything like the one in the picture! If you’d like more information about using different flours in your sourdough, check out my “Guide to Which Flour to Use for Sourdough”.

But really, the hydration level you choose will depend on your comfort in dealing with wetter dough, and how open a crumb texture you like.

A good basic hydration to go for if you are starting out is around the 67% mark. This will give a you a desirable crumb, without too much difficulty in dough handling. Thereafter, you can try increasing hydration by 1 or 2% at a time each time you bake, so you can compare the results and get to know where your limit is.

As a ball park figure, most sourdough bakers will use hydration levels of between 70 – 90% with desirable results.

NOTE: Some steps in the bread making process can be optional at hydration levels below 70%. But these extra steps become increasingly important once you reach hydration levels of more than 70% because more effort is needed to hold strength in a slacker dough. Extra steps include stretch & fold, autolysis, and pre-shaping. This may be something to consider if you are deciding on a hydration levels for your bread if you have a tight schedule.

How Much Hydration is Too Much?

There is of course a limit to the amount of water/liquid your flour can take. This again will depend on the flour you are using and how absorbent it is. But hydration levels can be pushed to 90 – 100%, especially with whole grain flours.

How do you know how much Water your Dough can Take?

Flour absorbency varies from flour to flour

The only way to know if the hydration level is too much, is to test it out and see how your dough reacts. If during the bulk ferment, you can see water seeping out at the top of the dough container, then this is a sign that the flour has absorbed all it can and the upper limit to the hydration level has been reached.

Now that you have some idea of what hydration levels you may want to aim for, we can learn about how to calculate hydration levels. But before this, let’s learn a little about hydration levels for sourdough starters…

Hydration Levels of Sourdough Starter

It’s quite common to keep a sourdough starter at 100% hydration, which means using equal amounts of flour and water to feed it. But this is not always the case. Some sourdough bakers like to keep their sourdough at a lower or higher hydration than this, and here’s why…

NOTE: The feedings for sourdough starter should always be done by weight in order to keep the hydration levels accurate. Feeding sourdough starter by volume will give you too much fluctuation, and it would be more difficult to determine the hydration level accurately.

Keeping your Starter at a Lower Hydration Level

Some bakers prefer a thicker/stiffer starter(lower hydration). A stiffer starter means it is fed more flour than water and so it is ‘stiff’. The lower the hydration level of the starter, the stiffer the starter will be. Most stiff starters are kept at between 50 to 70% hydration.

The wild yeasts and bacteria feed through the sugars and starches much slower in a stiffer starter, so it can go for much longer without feedings. This is handy if you can’t feed your starter too often.

On the flip side, there will be more acetic production in a stiffer starter, so the flavor of your bread will be more sour. (For more information about adjusting the sourness of your bread, check out my article “18 Ways to Make Sourdough Bread More (or Less Sour)”.

Keeping your Starter at a Higher Hydration Level

Keeping your sourdough starter at higher than 100% hydration allows you to be able to pour the hydration and mix it into the dough very easily. Most high hydration starters are kept at around 125% hydration.

They are very quick and easy to feed because the flour absorbs in really quickly, but they will also need feeding more often, because they feed quicker (this is because a wetter starter has more movement of the wild yeasts and bacteria). Higher hydration starters will also produce a more mild tasting loaf, as they tend to favor more lactic acid growth.

Here’s a quick summary of the pros and cons of keeping your sourdough starter at different hydration levels:

Stiff
Starter
Wet
Starter
100% Hydration
Starter
Usually
50 – 70% hydration
Usually
120 – 130% hydration
100% hydration
(equal amounts
flour & water)
Fed less oftenFed more oftenIn between
Harder to mixEasier to mixIn between
More sour flavorMilder flavorIn between

The benefit of keeping it at 100%, (and why I like to keep mine at 100%) is because it is easier to calculate hydration levels for your dough (as you will see in the next section below). And it’s also relatively easy to mix and feed.

You have the benefit of it being really simple to know how much flour and water to feed it; At 100% hydration you are always feeding it the same amount of flour as you are water.

QUICK TIP: It’s always recommended that beginner sourdough bakers work with 100% hydration sourdough starters. Once you become more experienced, you will develop a preference for what kind of starter you’d like to keep.

How Can I Change the Hydration Level of My Starter?

Bubbly active sourdough starter at hydration of 100%

You can easily change the hydration level of your starter by simply adjusting the amount of flour and water you feed it.

Here are some examples of how to adjust the hydration levels:

  • Sourdough starter at 100% hydration – If you are feeding it 50 grams of flour, then ‘100% of 50 grams’ is 50 grams. So you feed it 50 grams of water. i.e. equal amounts of flour and water or in other words:
    • The amount of flour x 1 = the amount of water.
  • Starter at 50% hydration – If you are feeding it 50 grams of flour, then ‘50% of 50 grams’ is 25 grams. So you will feed it 25 grams of water for every 50 grams. i.e. half the amount of water as you do flour, or in other words:
    • The amount of flour x 0.5 = the amount water
  • Starter at 70% hydration – So again, let’s say you fed it 50 grams of flour. This means you feed it 50 x 0.7 = 35 grams of water.
    • The amount of flour x 0.7 = the amount of water.
  • Starter at 125% hydration – If you are feeding it 50 grams of flour, then you need to give it 50 x 1.25 = 62.5 grams of water.
    • The amount of flour x 1.25 = the amount of water.

QUICK TIP: If you already have a starter going and wish to change it’s hydration, you can discard all but a tiny amount, and then feed it according to the new proportions. It’s not necessary to make a new starter from scratch. (For ideas on what to do with leftover sourdough starter, check out my article here)

How Do You Calculate Hydration Levels in a Recipe?

Now that we know all about hydration levels of sourdough starter, we can calculate hydration levels of the sourdough bread we are making. Here’s a step by step breakdown of how to calculate the hydration level of a specific recipe (we will follow up with a couple of different examples, so don’t worry if it look a little crazy to begin with!):

  • Step 1 – Calculate how much flour and water your starter contains and make a note.
  • Step 2 – Make note of how much flour and water you have in the recipe.
  • Step 3 – Add up the total amount of flour (i.e. the flour in your recipe, plus the flour in your starter). Do the same with the water. You now have 2 numbers. The total amount of water, and the total amount of flour.
  • Step 4 – The hydration calculation will be “Total amount of water” divided by “Total amount of flour”, and multiplied by 100. This number is the hydration level of your dough in percentage.

Let’s take a couple of different examples using a sample bread recipe. Here are the ingredients:

  • 180 grams sourdough starter
  • 600 grams strong white bread flour
  • 360 grams water
  • 10 grams salt

Let’s go through the steps for this particular recipe:

  • Step 1 – My starter is 100% hydration, therefore using 180 grams would mean 90 grams is flour and 90 grams is water.
  • Step 2 – the recipe contains 600 grams flour and 360 grams water.
  • Step 3 – Total amount of flour is 90 grams + 600 grams = 690 grams
    • Total amount of water is 90 grams + 360 grams = 450 grams
  • Step 4 – 450 grams (total water) divided by 690 grams (total flour) x 100 = 65% hydration

Let’s try an example of the same recipe but with a higher hydration starter being used:

  • Step 1 – My starter is at 125% hydration. So 180 grams would mean 80 grams of flour and 100 grams of water (because 80 x 1.25 = 100 grams; see above section for calculations)
  • Step 2 – The recipe contains 600 grams flour and 360 grams water.
  • Step 3 – Total amount of flour is 80 grams + 600 grams = 680 grams
    • Total amount of water is 100 grams + 360 grams = 460 grams flour
  • Step 4 – 460 grams (total water) divided by 680 grams (total flour) x 100 = 68% hydration
Always keep a notebook handy when baking bread!

How Can I Adjust the Hydration Level of a Known Recipe?

Now that we understand how to calculate the hydration of a known recipe, we are in a better position to be able to increase or decrease the hydration accordingly. Here’s a step by step guide, but again, we will follow it with a couple of examples:

  • Step 1 – Calculate the total amount of flour in your recipe (i.e. the flour in the recipe + the flour in your starter) and make a note.
  • Step 2 – Multiply the hydration percentage you want by the total amount of flour. This will give you the amount of water you need.

Let’s take a couple of examples:

Increasing the Hydration of a Recipe

Let’s take the same sample recipe we used earlier (which we calculated at 65% hydration), and go through some steps to increase the hydration by 2%. Here’s the original recipe once again:

  • 180 grams sourdough starter
  • 600 grams strong white bread flour
  • 360 grams water
  • 10 grams salt
  • Step 1 – We want to calculate the total amount of flour. Assuming our sourdough starter is at 100% hydration, the total amount of flour is 90 grams + 600 grams = 690 grams.
  • Step 2 – We want 67% hydration, which means we want 0.67 x 690 grams = 462 grams. This means we need a total of 462 grams of water in our recipe instead of 450 grams (360 grams from the recipe + 90 grams from the starter = 450 grams) if we want of hydration level of 67% instead of 65%.

Decreasing the Hydration of a Recipe

Now we’ll decrease that same recipe by 2% (so we want 63% hydration), and we will assume that the hydration of our starter is at 125%.

  • Step 1 – Calculate the total amount of flour. The sourdough starter is at 125% hydration, so this means that 100 grams of it is water, and 80 grams of it is flour. (see sections above regarding adjusting hydration levels of starters). So, total amount of flour is 80 grams + 600 grams = 680 grams.
  • Step 2 – We want 63% hydration, so 0.63 x 680 = 428 grams. This means that we need 428 grams of water for the recipe if we want a hydration level of 63%, using a sourdough starter of 125% hydration.

Tips when Working with High Hydration Sourdough

As mentioned earlier, the higher the hydration level of your dough, the trickier it can get to work with it. Here are a few tips I have picked up along the way when I’ve pushed the hydration in my sourdough.

Tip #1: Don’t Skip the Autolyse

To Autolyse, is to simply mix the flour and water of a recipe, and letting it sit for a period of time before adding the starter and salt. Autolysis is not an absolutely necessary step, but once your dough gets to a higher hydration level, having a longer autolysis can be the difference between a dough being handled well, and a dough lying in a pool of mess!

Autolysis allows the dough to become more extensible

Autolysis allows the flour to fully absorb and helps the dough to become more extensible, making it far easier to work with. In terms of how long you should autolyse for, you should leave the dough until you see a change in the ‘feel‘ of the dough. It will go from breaking apart if pulled, to becoming nicely extensible with some stretch without breaking. This may be anything from 20 minutes to a few hours.

Tip #2: Retard the Dough to Make it Easier to Handle

‘Retarding’ the dough by putting it in the fridge will help stiffen it up slightly, making it easier to work with. You can retard it during the last part (or all) of the bulk ferment stage in order to make it easier to handle and shape. But you can also retard the dough during it’s second rise. This will help to hold it’s shape better when turning it out of it’s proofing basket.

Tip #3: Flour your Proofing Basket Well to Avoid the Dough Sticking

Because your dough is going to be stickier, you will need to flour the proofing basket really well. The last thing you want after all the hard work and effort you put into making your bread, is for it to stick to the proofing basket when you try to turn it out! Using a coarse grain, such as dark rye or whole grain seems to work best for me, but many bakers use rice flour too because as it is quite good at preventing sticking.

Tip #4: Use Wet Hands When Handling Dough

Using wet hands when handling the dough is a game changer when working with wet dough. It will prevent the dough from sticking to your hands so you can concentrate on handling the dough instead of your hands!

Simply dip your whole hand in a bowl of water and sprinkle off the excess, or spray a mist of water on your hands just before handling. If needed, you can do the same again even during the dough handling to stop any further sticking.

BONUS TIP: When it comes to scoring your loaf, an extra sticky dough will benefit from using a wet blade to score with. Simply dip it in some water just before scoring, and it will help the blade glide through without as much resistance.

Tip #5: Use a Dough Scraper

With lower hydration dough, you can get away with using just your hands, but a wetter dough needs a dough scraper as an extension to your hands. Wet the dough scraper the same as you would your hands, and use the dough scraper as the dominant contact for your dough, with your other hand being a support.

TIP: Really wet dough can be handled using 2 dough scrapers, one in each hand.

Tip #6: Uncover the Dough Halfway through the Bake

Higher hydration dough will produce a thinner crust when in the oven. To make it nice and crispy, remove it’s cover or steam source halfway through the bake to make sure it crisps up nicely.

On the flip side, a lower hydration dough can produce quite a thick, hard crust. I have found that keeping my bread covered throughout the whole bake actually produces a better crust that remains crispy but is not too thick.

Tip #7: Pre-Shape the Dough to Help Slack Dough Stand Tall

Pre-shaping is not necessary at all for lower hydration dough. But a wet, slack dough will benefit from a pre-shape before it’s final shape. It will help to further develop structure in the loaf and help it to stand taller.

Leave 20 minutes to one hour in between the pre-shape and final shaping to help the dough relax in between. You will also find that shaping is easier during the final shape if it has had a pre-shape!

Aysha

I've been baking sourdough bread at home for years now and have had a journey full of successes and failures. This has given me great experience in understanding what makes a good bake!

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