Learn how to make your own Sourdough Starter, with just two ingredients and in a few, very simple steps. Here I also explain what is feeding, how to take care of the Starter and how to use it to make bread.

What you can find here:

• What is a Sourdough Starter?
• What you will need
• The step-by-step process to make a Sourdough Starter
• What is feeding
• How to take care of a Sourdough Starter
• How to use a Sourdough Starter to make bread

What is a Sourdough Starter?

Sourdough Starter is simply a mix of flour and water that creates a complex community of microorganisms (yeast and bacteria), which ferment the dough and give a characteristic flavor and texture to the bread¹. Bacteria like Lactobacillus produce the acid in the starter and the yeast like Saccharomyces produce carbon dioxide that makes the dough to rise. These microorganisms are present in the air and in the flour itself, between other sources, and can vary depending on the geographical region. For this reason, your and mine sourdough starter will probably have different colonies of yeast and bacteria and thus differ in flavor, smell and texture.

With a sourdough starter you can make bread (like this Easy NO-KNEAD Bread) without the use of commercial yeast, since the starter will ferment the dough by itself. Nevertheless, you can still combine the starter with the commercial yeast to boost the fermentation and decrease the resting time.

What you will need:

• Flour: You can use any type, all purpose or bread flour, white or whole grain (I prefer to start with whole grain, because since it is less processed, it might contain more nutrients and microorganisms that facilitate the first steps of fermentation). You can also use different grains other than wheat, like spelt or rye, depending on the bread that you want to make.
• Water
• Container: a jar (better if it is wide-mouth), a tupperware or any other container of your preference (transparent, so you can see the dough rise)
• Rubber band or permanent marker: to monitor the dough development
• A piece of cloth (e.g. cheesecloth) and a rubber band (for the first days).

The step-by-step process to make a Sourdough Starter:

From scratch to being able to make your first sourdough bread, it will probably take you 5 to 7 days, but as I said before, it will depend on your geographical region and on the ambient temperature.

This process that I explain here will give you a Sourdough Starter with the 100% of hydration. This means that the Starter will contain equal amounts of flour and water, an important characteristic to take into account when making bread.

Day 1

• 9:00 am. Combine the same amount of flour (whole grain recommended) and water (e.g. 100 g flour and 100 g water), depending on the size of your container (it should be no more than half-filled) and mix. The consistency should be like a slurry (see the pictures).
• Cover the container with a piece of cloth to allow the air to be in contact with the dough but keeping dust and dirt out.
• Place a rubber band around the container at the dough level or make a line with a permanent marker (I clean the walls of the glass to have a clear vision of the dough level and to take the pictures, but you don’t need to do it).
• Keep the dough in a dark place, with no air currents (better if it is a bit warm) for 24 hours.

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Day 2

• 9:00 am. Maybe the dough has risen a bit, which you can check by comparing the dough with the rubber band or line. But this is not common, and most likely the dough has no visible activity.
• Today you are just going to stir the mixture with a spoon or knife. A crust has probably formed due to air contact. It doesn’t look nice, but it is totally fine. Just stir the dough and place the rubber band at the dough level.
• Now cover with the glass lid and place it in a dark place for 24 hours.

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Day 3

• Today you might see some activity and bubbling on your dough. It might have even risen! Mine had already peaked (by 8:00 am) and deflated (which you can notice by the dough mark on the glas), which really surprised me because this happened in very little time. Usually, when I’ve made sourdough starter from scratch before, it took longer than 3 days to “double” its volume. This shows that every time you do a starter it will be different depending on the environmental conditions (Temperature, humidity) and the type of flour that you use. Do not worry if your starter takes longer to show activity, just give it some time more.
• Either way (showing bubbling or not) you are going to FEED THE STARTER: feeding the starter is simply emptying half of the mixture and adding equal parts of water and flour until you get a similar slurry consistency as before (approximately 50 g of flour and 50 g of water). You should achieve an amount of dough that reaches more or less until the middle point of your container, but not higher, because the dough can rise too much and overflow.
• Since the dough is already active, I checked it again at night (11 pm) and saw that it was rising.

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Day 4

• 8:30 am: This time the dough did not rise that much (it did not double in size), and however, it already peaked and it was in the process of deflating.
• Throw again half of the dough and feed with equal parts of water and flour until the mark.
• 1:30 pm: The dough is in the rising process
• 6:30 pm: The dough has already peaked and is deflating. I threw away half of the mixture and fed with equal parts of water and flour until the mark

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Day 5

• 11:00 am: The dough peaked and deflated. It has a lot of activity and I would consider it “almost done”. I threw away half of the dough and fed it again with equal parts of water and flour.
• 3 pm: In just 4 hours it doubled in size. Here you can see that it still has strength and that it’s rising, but since it achieved its “doubling” size, it will peak and deflate soon. At this point our sourdough starter is full of life, very active and ready to bake bread! You can notice that by the convex shape on its top (kind of like a mountain).
• You can directly use it to make bread or you can store it in the fridge. In the cold environment of the fridge, the bacteria and yeast in the starter will slow down their activities and the dough will not increase, but keep alive.

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How to take care of a Sourdough Starter?

• You can store the dough for as long as 2 months in the fridge, or longer, although I recommend taking it out and feeding it every 1 or 2 weeks. This will prevent it from getting too acidic.
• To feed the dough: throw away (or make a sourdough pancake!) half of the dough and add equal amounts (around 50 g) of water and flour. You can use normal wheat flour, whole wheat flour (what I personally do), or start adding other cereals. I have not tried to mix other cereals with my wheat sourdough starter, but you can try it and feel free to let me know how it went!
• If you leave your sourdough starter in the fridge for longer than 2-3 weeks it will start to create a black liquid on the top, and to smell really acidic. However, if it has no mold or smells like sewer, it is still good to use! You just have to throw away half of the dough and feed it one or two times before using it in a recipe. In this post I show you step by step how you can feed a starter that has been sitting in the fridge for too long.

How to use a Sourdough Starter to make bread?

• You should take your starter out of the fridge a few hours before you plan to start making the bread, for example the night before, and feed it as usual.
• After around 6 hours or the next day your starter should have risen (although it depends on the activity of your starter and the feeding ratio. My starter is ready to use after just 1 1/2 – 2 hours, with a 1:1 starter : feeding ratio). It is best to use the starter when it is still rising and has strength, rather than after it has peaked and it is deflating. However, you can also use it when it has deflated, it will only be a bit more acidic.
• Once your starter has risen you can use the amount that the recipe is asking you to use. You can check this Easy No-knead Sourdough Bread recipe that I posted.
• If very little starter is left in your container, I would feed it again, let it rise for a few hours and store it in the fridge while it is still rising. If you have enough starter, you can directly store it in the fridge for your next bake day!

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Resources

1. Reese AT, Madden AA, Joossens M, Lacaze G, Dunn RR. 2020. Influences of ingredients and bakers on the bacteria andfungi in sourdough starters and bread. mSphere 5:e00950-19. https://doi.org/10.1128/mSphere.00950-19.