Long Fermented Sourdough Bread

This long fermented sourdough bread recipe brings together a complex depth of flavor with the nutritional health benefits of fermented foods. Long fermented sourdough bread takes a bit longer than other artisan style breads, but most of the time is hands off, so you really just need a lot of patience!

This is a true sourdough bread with no commercial yeast at all - the wild yeasts are essential for the longer fermentation process required.

The key to this recipe is adjusting your starter amount and temperatures to facilitate longer fermentation times.

This recipe is best suited to plain sourdough bread, without add ins. This long fermented sourdough bread utilises a longer cold fermentation process than regular sourdough bread and thus I believe it's best to work with a "lean" dough (at least until you have the process down pat and understand the way your dough behaves).

This long fermented sourdough bread recipe will give you an artisan sourdough bread rich in flavor with a crackly crust and open crumb. It's best suited to people who like a deeper level of sour flavor or require a lower level of gluten and phytic acid. If you really do like big flavors, you might also enjoy this hearty sourdough rye bread.

If you'd prefer a quicker recipe, you might like this same day sourdough bread recipe.

You can find my beginner sourdough resources here:

• Sourdough Glossary (50+ sourdough terms explained)
• How to Make a Sourdough Starter from Scratch
• Sourdough for Beginners (simple sourdough bread recipe)
• Bulk Fermentation Explained

What is the importance of a long fermentation in sourdough bread?

True sourdough bread is made using a sourdough starter that has been colonised with wild yeast and lactic acid bacteria. The wild yeast in your sourdough starter consume the sugars in the flour and rise your bread by producing CO2 that is trapped inside the gluten network. But, perhaps more importantly, the bacteria in your starter break down the gluten in your dough, making the resulting loaf much easier to digest, even if it's made with white bread flour.

The longer the dough ferments, the more digestible the sourdough bread becomes (and the stronger the sourdough flavor becomes too!).

In fact, a long fermented sourdough bread makes the nutrients much more available to your body. It produces a lower surge in blood sugar, which means that it is a lower glycemic index food.

This is so much better for you than regular bread which can cause big spikes in blood sugar, rather than prolonged energy release.

This makes long fermented sourdough bread much better for you!

How to make Long Fermented Sourdough Bread (step by step guide)

You can use white bread flour or whole wheat flour for this recipe. You will get the best results from using straight bread flour, but blending up to 50% whole wheat can give you a good complexity of flavor too. I don't recommend using all purpose flour for this recipe.

This is not a high hydration dough and should be fairly easy to handle at around 70% hydration.

I've outlined the process of making a long fermented artisan sourdough bread in a step by step guide (you'll also find the process written into the recipe card at the end of this blog).

I have based this long fermented sourdough recipe on my original recipe for simple sourdough bread.

DAY 1

Step 1 - Feed Your Starter

Get your sourdough starter ready by taking 50g of starter and feeding it with 50g of flour and 50g of water. You'll use this in your dough once it's at its peak.

An active sourdough starter will give you the best fermentation! Remember to use a rubber band so you can see when your starter is at its peak. You can read more about the best time to use sourdough starter here.

Step 2 - Autolyse

Weigh out your sourdough starter and water into a large ceramic or glass bowl.

Mix the water and starter together briefly. Then add your flour and salt and mix whole lot together to form a shaggy dough.

Cover your bowl with cling film or a damp tea towel and let it sit for around 1 hour. It's ok if it's a little bit longer, it's not going to matter too much.

I find a dough scraper the easiest way to mix it as you can keep the sides of bowl clean. The dough will be fairly shaggy and only just brought together.

You might wonder how this will turn into bread, but just wait, time is your friend and the dough will change in around an hour. This process is called the "autolyse" and allows your flour to soak in all the water and become hydrated.

Step 3 - Forming Up The Dough

After the dough has been through autolyse you need to bring it together into a ball. Work your way around the bowl, grabbing the dough from the outside, stretching it up and over itself, into the centre, until a smooth ball is formed. You shouldn't need more than about 20-30 stretches to form the ball.

Once the dough has formed into a smooth ball, pop the cling film back on and let it rest for 30 minutes.

You'll notice that the dough is fully hydrated after soaking all the water up. It will be fairly sticky but as you bring it into a ball, it will become smoother and shinier.

Step 4 - Stretch & Fold

• Over the next few hours you need to create some structure for your dough by "stretching and folding".
  
• Aim to do around 4-6 sets of stretches and folds.
  
• For each set, stretch the dough up and over itself 4 times. Leave around 15 minutes in between each set. Again you do not have to be exact with time, but you need to do at least 4 sets over 2 hours.

Step 5 - Bulk Ferment (Dough Rise)

Once you've finished your stretch and folds, place the cling film or damp tea towel back over your dough and let it rest and ferment (a plastic cover is a better option for this stage).

You want to allow your dough to rise until it's JUST UNDER DOUBLE. This dough has a low percentage of sourdough starter and is suitable for an overnight fermentation.

DAY 2

Step 6 - Shaping

Once your dough has finished its first ferment, it's time to shape it into either a boule or a batard.

You'll need to flour your counter top with rice flour for this (we use rice flour because it has no gluten). Try to be quite sparing with the rice flour, you only need a very light dusting.

Use a silicone dough scraper to gently ease the dough out of the bowl. You want it to land upside down on your counter so that the smooth top of the dough is on the countertop and the sticky underside is facing up. This will make it easier to shape.

You want to pull the edges of the dough into the centre and then flip it over so that the sticky side is now underneath. Using the stickiness, gently pull the dough into a tight ball.

You will need a banneton to put your dough into. If you do not have a banneton, then a bowl or basket lined with a floured tea towel is perfectly fine. Make sure your bowl isn't too big though, you want your dough to retain some shape.

Whatever you're using needs to be liberally floured with your rice flour. If you're using a banneton - liberally sprinkle it with rice flour. If you're using a cloth or tea towel, rub the flour into it to ensure it becomes non stick. A floured proofing basket is key to non stick sourdough!

You can use this video to see how I've shaped the dough into a boule.

Step 7 - Placing into a Banneton

Once the dough is shaped into a tight ball, place it into your banneton smooth side down, so your seam is on the top - this way the top of your dough will get the pretty lines from the banneton.

If you're using a cloth or tea towel in a bowl it's ok to put your dough with the smooth side up. Just make sure the dough is tight.

Lift your dough around the edges to pop a little more rice flour if you feel it needs it. Just try to handle the dough as little as possible and be really gentle as you really want to preserve all the gases and air bubbles that have formed during your bulk ferment.

Step 8 - Cold Ferment (The Key to Long Fermentation)

Now the dough is in its "shaping container" cover it loosely with a plastic bag or damp tea towel and place into the fridge. You will need to leave your shaped dough in the fridge between 24 to 48 hours (or anywhere in between). It's super important that your fridge is set to the correct temperature for this (3C or colder)!

I use a large plastic bag to cover it - I just reuse it each time. This period of cold fermentation is the KEY to long fermented sourdough bread!

Step 9 - Preparing to Bake

Once you're ready to bake your sourdough, you'll need to preheat your oven to 230C/450F.

Place your Cast Iron Dutch Oven into the oven when you turn it on so it gets HOT. Try to preheat for around 1 hour to ensure your oven is super hot - but you know your oven so just adjust this time if you need to.

Leave your dough in the fridge until the very last minute - placing a cold dough into a hot oven will give you a great "spring".

Step 10 - Bake Time!

Now it's time to bake!

When your oven is at temperature, take your sourdough out of the fridge. Gently place it onto a piece of parchment or baking paper.

Make sure that you make the parchment paper big enough to use the edges as a handle to lower to dough into your Dutch Oven.

Gently score your bread with a lame, clean razor blade or knife. At minimum a large cross is sufficient, but you can get as artistic as you like. You can find my full guide on how to score sourdough bread here.

Carefully take your dutch oven out of the oven. Place the sourdough into the pot using the baking paper as a handle. Put the lid on and place into the hot oven.

BAKE TIME:

30 Minutes with the lid on at 230C/450F plus
10-15 Minutes with the lid off at 210C/410F

Step 11 - Finishing The Bake

When you remove your dough from the oven, carefully remove it from the dutch oven as soon as possible and place on a wire rack to cool.

Why is temperature so important in long fermented sourdough bread?

Temperature is so important to sourdough bread and the fermentation process because it will determine how long the bulk fermentation and cold fermentation last. Bulk fermentation is always done at room temperature and it is this part of the process that allows the yeast to rise your sourdough bread. The temperature of your kitchen, along with the amount of sourdough starter, will determine the length of bulk fermentation.

Similarly, the temperature of your fridge will determine a successful cold fermentation. The cold fermentation should be conducted at temperatures at 3C or lower. If your fridge is warmer than this, your shaped sourdough will over ferment too quickly to reap the benefits of an extended fermentation period.

Lower temperatures, along with a lower percentage of sourdough starter will enable you to ferment your sourdough for a longer period of time, maximising the health benefits. The trick with long fermented sourdough is to balance the break down of gluten which occurs during the cold retard with the desired oven spring. It can be a difficult thing to achieve.

You can read more about the differences between bulk fermentation and cold fermentation here.

Baker's Timeline for Longer Fermentation

The great thing about long fermentation is that you can make it work for you. Most of the time invested into this recipe is hands off. The dough will spend more time in the fridge than it will in your hands! Pretty cool, right? All those good bacteria do the hard work for you!

This timeline is an example only and you can change it to suit your needs. This one has the process starting on a Wednesday and finishing on a Saturday morning - giving you delicious freshly baked sourdough for the weekend!

DAY 1 (Wednesday)

2pm Feed sourdough starter

7pm Stretch and Fold

9pm Bulk Fermentation overnight (make sure temp is below 21C)

DAY 2 (Thursday)

6am Shape the dough and place into the banneton then into the fridge for cold fermentation.

DAY 3 (Friday)

Just leave your sourdough in the fridge - try to place it at the back of the fridge where it's coldest. It will be in there for 48 hours.

DAY 4 (Saturday)

6am Preheat the Oven

7am Bake your sourdough bread!

You can learn more about sourdough baking timelines here.

Can Sourdough Ferment Too Long?

Yes sourdough can be left to ferment too long. If you leave your dough to ferment for too long during bulk fermentation you will end up with soupy dough that cannot be shaped into a nice boule or batard. There is a limit to bulk fermentation, however it can be manipulated by adjusting the amount of sourdough starter you use and or the temperature of your kitchen.

Sourdough can also be fermented too long during cold fermentation because if you leave it in the fridge for extended periods you risk the lactic acid bacteria breaking down the gluten structure to a point where it can no longer contain the CO2 produced by the yeast. This is result in a loaf that collapses when you tip it out of the banneton.

The trick to long fermented sourdough is to balance the desired flavor with the gluten structure. This can be difference between good bread and great bread!

How Long Should You Ferment Sourdough Bread?

This really is a tricky question because fermentation time depends on your sourdough starter strength and age, the amount of it you use and how warm your environment is.

Typically, bulk fermentation will take between 6 to 8 hours, but could be longer or shorter by manipulating starter amount and temperature.

Ideally, you don't want to allow sourdough bread to cold ferment for longer than 72 hours. Even up to 48 hours, you do risk some loss of gluten structure unless you manipulate the amount of starter down.

Frequently Asked Questions

Share the sourdough love!