Sourdough Bread Formula
Creating your sourdough starter (or receiving it from a friend or buying it) is just the first step on a long journey with great bread. A journey that can span decades and continue for generations to come.
So, with the starter bubbling and ready to be used, it’s time to put those yeast cells and bacteria to work and bake some real, honest sourdough bread. Bread made with nothing but flour, water and salt – and time, the most important of all ingredients.
Is my sourdough starter ready for bread making?
Before you get to work on making your first loaf of sourdough bread, you probably want your starter to be active and full of rising power.
My first advice is to not stress about this too much. Actually, that’s my first advice regarding every step of the bread making process: yes, take some time to think about what you are doing, but don’t worry too much if you miss one stretch and fold sequence or accidentally add a little too much water.
Think of each of those mishaps are opportunities for learning. What’s the worst that could happen?
So, if you think your starter might be ready but aren’t quite sure, just go ahead and make some bread. Once you have baked your bread, you will know if your starter was ready or not.
That said, there are a few signs and tools that can help you in assessing the readiness of your sourdough starter:
- When refreshed at a consistent 24 hour cycle – for example every morning at 8 – the starter should rise and then collapse reliably, reaching its peak some time during the first 12 hours after the refresh. Again, the timing varies depending on many factors such as temperature, the age of your starter, and so on. But the point here is to notice a clear change in the starter.
- When at its peak, the starter should be foamy and full of bubbles of different sizes. You can look at the photo above for an example (even though the starter pictured is already a bit past its peak). The smell should be sour but pleasant, reminding a mix of yoghurt and sauerkraut or pickles.
- Finally, if you think the dough looks good, but aren’t quite sure, you can do a float test. Take some cool water (the exact temperature isn’t important, 25°C or so works fine) and pour a spoonful of your starter in the water. If the piece of starter floats (see photo below), it is ready to be used. If it sinks, that’s a sign that there isn’t all that much gas in the starter, which makes it heavy – and means that not much fermentation has happened yet.
Once you practice making bread, you will learn to judge the starter by its look, smell – and taste, and the float test becomes something you rarely do. But at first, it’s a very useful tool.
Step 1: Prepare the starter
The process of making a sourdough bread begins on the night before you want to make your bread (or more precisely, 8-10 hours before you start mixing the dough).
The starter gets more sour the longer it ferments, so following the lead of Chad Robertson and many other great bakers, I like to use a relatively “young” starter in my bread making. It has to pass the float test described above, but shouldn’t be too ripe.
Which is why when we start making the bread, we bread out of our normal 24 hour cycle a bit, and add one more refreshment right when the starter is at its peak.
To do this…
- Take one full tablespoon of the sourdough starter and place it in a clean bowl. Leave the rest of the starter and refresh it normally in the morning.
- To the new bowl, add flour and water at a 50/50 ratio (or 100% hydration) to mix a new starter. How much flour and water you add depends on the size of the dough you are making. We’ll get to this soon, but for this recipe, add 150 g flour and 150 g water.
- Stir the ingredients so that no dry lumps of flour remain.
- Cover the bowl with plastic wrap and leave at room temperature.
In the morning, you will have a total of roughly 300 grams of young but ripe sourdough starter waiting for you to bake bread with it. We won’t use all of it, but as some of the starter inevitably gets stuck to the sides of the bowl, it’s good to make a little extra…
Step 2: Mix the dough
In our basic bread formula, we use 2% (in bakers’ percentage) fresh yeast. Now, as we are making sourdough bread, we will replace the yeast with the sourdough starter. As the sourdough is not just yeast cells but also a good deal of flour, water and lactic acid bacteria, 2 percent isn’t enough.
The exact amount of this “fermented flour,” as it’s often called, depends on the type of bread you are making – you can find your preferred amount through trial and error. In this article, we are going for a basic, pleasantly sour sourdough bread. For that kind of bread, using a starter at 100% hydration such as the one created in the previous article, I like to go with 20 to 25 percent (bakers’ percentage) or sourdough starter.
Here’s the formula, in bakers’ percentages and weights, using 1 kilo of flour.
- 85% bread (or all-purpose) flour
- 15% wholemeal wheat flour
- 70% water
- 25% young, ripe sourdough starter
- 2% salt
And the same in weights, using 1 kilo of flour:
- 850g bread (or all-purpose) flour
- 150g wholemeal wheat flour
- 700g water
- 250g young, ripe sourdough starter
- 20g salt
For the more advanced – or curious – readers, here’s the recipe as an interactive BreadStorm formula. Using this element, you can scale the recipe and see how the changes in the total flour or weight affect the other ingredients:
Mix all ingredients except salt in a bowl until no dry lumps of flour remain. I like to mix the dough using a plastic scraper: hold the scraper in your right hand (or left if you are left-handed) and then use your other hand to rotate the bowl while you scoop the dough with the scraper.
Cover the bowl and leave it aside at room temperature for 30 minutes.
After 30 minutes, add the salt and fold it in the dough until it feels fully incorporated.
This is advanced stuff, which you can skip if you are just baking your first sourdough bread. But for those interested, there more to calculating the bakers’ percentages with a sourdough starter.
You may have noticed that as we add 25% sourdough starter in the dough, we are actually adding both flour and water, which naturally also changes the overall hydration of the final dough. In the recipe however, to make the recipe easier to follow, I decided to mark the starter as another ingredient rather than including it in the flour and water.
It’s a common practice, but if you want to know the exact hydration of the dough you are making, in your calculations you need to divide the starter into flour and water (125 g of each) and add those to the flour and water respectively. This will tell us that the dough actually contains 1125g of flour and 825g of water, making this a 73% hydration dough rather than 70%. A small, but sometimes meaningful difference.
Step 3: Strengthen the dough
From here onward, making sourdough bread doesn’t really differ all that much from making bread using commercial yeast. Everything just happens slower, making the process more enjoyable and peaceful (if also harder for the impatient among us – myself included).
With the dough mixed and all the ingredients in place, it’s time to build some strength into the dough so that it will be able to hold its form throughout the rest period as well as when it is baked. As we saw in our kneading technique roundup, there are many ways to do this: with or without kneading the dough.
If you cannot devote the next few hours to closely following the dough and working on it every half an hour, you can knead the dough for about 10 minutes and then let the dough rise until roughly doubled in size.
However, if you are near your dough and can spare a few minutes every half an hour, the better and more gentle way of doing this is to add strength little by little, stretching the dough every half an hour.
Here’s how you do it:
- Without taking the dough out, grab one corner of the dough.
- Stretch that corner over the dough.
- Press down to seal the seam. Do this tightly at first, and then, as the dough gets more gassy after a couple of hours, start handling the dough in a more gentle manner.
- Leave the dough to rest in its bowl for 30 minutes, then repeat.
And the same in video:
Finally, you can go with a combination of the two approaches, kneading only briefly, maybe five minutes or less, and then following the process with a series of stretch and fold sequences. Also, even if you go with a longer kneading, at the beginning, adding a couple stretch and folds at about every hour or so can help distribute the carbon dioxide inside the dough more evenly.
Step 4: Shape the breads
After about four hours (the exact duration of the fermentation depends on many things, including how active your starter is and the temperature in your kitchen) the dough should be ready for shaping.
Deciding when a dough is ready is an art form in itself, and with sourdough, as every sourdough culture is different, it’s hard to give exact time estimates of how long to wait. As you make more bread with your starter, marking down the time it took to get to the ready state, you will learn the approximate time it takes for your starter to process your dough. That said, the estimate above is a good starting point…
Once you decide your dough is ready to be shaped, proceed with the shaping just as you would with a regular yeasted dough. I usually divide the dough into two and then shape both pieces into round loaves.
Just remember that the dough will go through one more long rest period, so it needs to have good strength or some support, such as the Banneton baskets commonly used by artisan bakers around the world.
Depending on the temperature and how active your starter is, by the time you have shaped your breads, it’s probably late afternoon or evening and you now have the choice between either slowing down the fermentation a bit more by cooling the loaves in the refrigerator (or outdoors) or baking the bread still the same night.
Step 5: Final Rise
Let the shaped breads proof, either in a cool environment to bake in the morning or in a warmer location to bake the same night.
And now, finally, you get to bake the bread (at 230°C / 446°F)!
For best results, use a dutch oven or otherwise cover the bread for the first 25 minutes of the bake to capture the steam escaping from the bread dough. This prevents the crust from forming too early and gives the bread a chance for a big final rise – the oven spring. After removing the cover, bake for another 20 to 25 minutes to give the bread a deep, golden brown, even a bit dark crust.
For more ideas, you can check my earlier blog post, 15 Ideas for Better Bread.
Let the bread cool down, then enjoy! You have baked a great loaf of sourdough bread and are well on the way to becoming a great baker.