Photo by Francis Storr, CC BY-SA 2.0

If you have ever tasted a good sourdough bread, maybe you have asked yourself the question: “How can I make bread like this myself?”

Look no further. In this article, I am going to give you the tools to start your own experiments. It’s fun, it’s not hard at all, and you can get started right away.

At the risk of sounding totally nerdy, I will say this anyway: creating my own sourdough starter and then keeping it alive has been one of the most interesting and rewarding experiments I have done in my life.

Watching the living organism — or more precisely, an entire world inhabited by yeasts and bacteria — grow and fall as the result of the microscopic life inside the jar is a lot like magic.

You are creating life out of thin air.

But creating a sourdough starter is not really magic. It is science that has been practiced by our ancestors for hundreds if not thousands of years. Science that has enabled them to create delicious and nutritious bread, loaf after loaf — without even understanding what it was that was happening in their pots of sourdough starter or mother dough.

Should you create a sourdough starter?

Before we get started with the tutorial, there is one more thing to consider: Do you want to create your own sourdough starter or would you rather get a starter from someone (for example through the Bread Matters Fungal Network) and then get right to baking your bread?

If you have friends who bake bread using a sourdough starter, I am sure they will be happy to share some of their own culture with you. In fact, I can promise they will be thrilled if you ask, knowing that one of their friends is about to join them in the appreciation of great, slowly fermented bread.

And, as you will soon notice, keeping the starter alive means throwing out most of the sourdough starter at every refresh — so by giving you a bit of the extra, they lose nothing.

There are also people and small businesses that sell sourdough cultures (the Raimugido rye starter is a great example and a product I like a lot). So, if you like, you can skip the step of creating your own starter and still start baking with sourdough. In that case, you can skip right to next week’s post where we will use the starter to bake some bread — or if you want to start baking bread right away, here’s a good basic sourdough bread recipe from the beautiful Kokblog.

If you decide to buy a sourdough starter, make sure it is the real thing and not fake sourdough sold in supermarkets with no rising power in itself.

A good way to confirm that a product marketed as sourdough really is sourdough is by checking the instructions on the package: if they ask you to add yeast, the product is or not what it claims to be. A real sourdough starter should be able to make your dough rise without the help of added yeast.

This tutorial is a slightly edited and updated version of my original sourdough starter article, first published in the Autumn 2012 (Fermentation) issue of BREAD — an issue dedicated to fermentation and one of my all time favorites so far.


Tools needed

  • Container (e.g. a bowl or a jar)
  • Spoon


  • Wholemeal (wheat) flour or dark rye flour
  • Bread flour
  • Water

To create a sourdough starter, this really is all you need — in addition to time (the project will take about 5 to 7 days from start to finish, but just a few minutes per day).

You may have read articles that tell you to use raisins or other fruit to get the fermentation going. Some bakers add sugar to the mix, and I have even heard of people beginning sourdough starters with the help of some commercial yeast.

I don’t believe any of those are necessary: as the point with a sourdough starter is to create an environment suitable for the growth of the right kind of bacteria and yeasts, it is best to start right away with the kind of diet you will be feeding the starter for the rest of its lifetime.

If, after a few days, your starter isn’t bubbling, the first thing you should check is your flour: If your flour is “dead”, it probably won’t be able to sustain the yeast culture being born. Try a good, organic flour instead. And only if this doesn’t help, consider using fruit or raisins to get your starter going.

And never use commercial yeast to start a sourdough starter.

Now, with that covered, let’s get started. To complete the project and have a sourdough starter going, you’ll need a couple of days or up to a week, depending on the conditions. In cold temperatures, the starter will take a little longer to come alive.

Step 1

Let’s start with the container. It can be a glass jar or a small bowl of any kind, big enough to fit your starter — but not too big so you can store it conveniently. I have used a glass jar (as shown later in this article), but these days I keep my starter in a plastic container of roughly one liter in volume. It’s a little bigger than what I need — but not by much.

When it comes to cleanliness I follow Sandor Katz’s lead and go for clean instead of sterile. In The Art of Fermentation, he writes:

My motto is cleanliness, not sterility. It is certainly important to work with clean hands, utensils, and equipment, but in general sterile conditions are not necessary for fermentation.

If you like to be sure, however, there is nothing wrong with cooking the bowl to sterilize it before the first time you mix the starter. I have never done this and my starters have always worked out just fine — just wash the container as you normally wash your dishes and rinse thoroughly to make sure there is no dish washing soap left.

With your container ready, let’s mix the batter that will become your sourdough starter.

At this point, the exact amounts of flour and water don’t matter all that much. You just need to get a thick batter with a 50/50 ratio of the flours you are using. But as it’s often easier to work with exact numbers instead of vague definitions like this, for the sake of clarity, here’s an exact recipe for the first step:

  • 50 g wholemeal wheat (or rye) flour
  • 50 g bread (or all-purpose) flour
  • 100 g water

To make it easier to measure the right amount of both flours, you can do what Chad Robertson recommends in Tartine Bread and create your own mix of flours which you store in a separate container. To do this, just combine 1 kg of wholemeal flour with 1 kg of bread flour and mix well.

This way, you can just measure 100 grams of flour straight from that mixture instead of measuring 50 grams of the two different flours separately. A small detail, but one that can be helpful in the long run…

For water, I am lucky to live in a country with very high quality tap water, so I always go for tap water. If the tap water where you live is highly chlorinated, you will need to dechlorinate it by letting the water stand in an open vessel on the kitchen counter for at least 4 to 8 hours to make the chlorine evaporate.

As a final resort, there is also the option of using bottled water. But I really would do this only if that’s the water you normally use for drinking — mostly for cost but also for ecological reasons. Sure, water is a big part of the taste of the bread, but if it’s good enough to drink, it should be good enough for baking.

Water should be warm but not hot, a bit cooler than your body temperature (32°C is ideal, but I always just estimate the temperature by trying how the water feels on the palm of my hand).

The main rule here is to use water that tastes good and doesn’t have too much chlorine so that it would inhibit the growth of yeasts and lactic acid bacteria in the starter.

Step 2

This will become a sourdough starter Cover the mixture loosely.

If you are using a jar, don’t put the lid on yet. Yeast requires oxygen to multiply, so it’s important to give it a good supply of fresh air to “feed” on. Also — although there is disagreement on this — some bakers say that many of the wild yeasts and bacteria in your starter are caught from the air.

What I do when creating a new sourdough starter is that I mix the batter to allow some air into it and then cover the bowl or jar with a kitchen towel I have dedicated to bread making (it has traces of flour and dough from earlier bakes on it — and therefore maybe also some lactic acid bacteria and yeasts, who knows?).

Place the starter in a warm, draft-free place. Especially in summer time, the kitchen sink works very well. I have found that a sourdough starter is not very picky. Those bacteria are strong beasts.

Then, for a couple of days as the starter is slowly coming to life, watch and enjoy the process. Stir the batter vigorously at least once a day to get some air inside and encourage the growth of yeast cells.
And wait.

Step 3

When your starter is full of bubbles and starts to smell distinctly sour, it’s time to start training it to grow and fall along to a consistent feeding cycle. As you refresh your starter at the same time every day, you will notice how it becomes more predictable and reliable with every refreshment. And this continues still long after you have baked your first sourdough breads. Keep taking good care of your starter and it will reward you for the effort!

Here’s what we do — in most cases on day three. I like to do this in the morning, but pick a time that suits your schedule. For the next few days, you will have to be prepared to repeat this step at the same time every day.

Mix in a clean bowl:

  • 25-30 g (one big tablespoon) of your active starter
  • 200 g flour (100 g wholemeal and 100 g bread flour)
  • 200 g water

Stir well. Again, the amount of flour you use is not very important. What matters is the ratio between water and flour. I like to maintain a starter at 100% hydration as it’s easy to stir. And having equal amounts of flour and water in the starter makes recipe calculations easier.

Discard the remaining starter and place this new starter in the container in its place. If throwing starter away feels bad, you can check our Fermentation issue for some ideas on how to use your extra starter, or consider what Ken Forkish says in Flour Water Salt Yeast and think of the discarded sourdough starter as “spent fuel” that has already done its work.

For the next couple of days (or longer, depending on the activity of your starter), keep repeating this process at the same time every day. While doing so, pay close attention to how the starter looks, feel and smells. This will help you later when analyzing the level of fermentation — be it in a starter or a bread dough.

And soon, you will have a strong and lively sourdough culture ready for using in bread making.

Step 4

Getting there After a few days of regular feedings, you will start to notice that your starter has a clear routine: assuming you refresh the starter in the morning, you can see that it first grows throughout the day, and then falls down so that by the time you feed it again, the starter looks about the same as it did before your last refresh. The cycle is probably not exactly a 24 hours, but close enough — and getting more reliable every day.

When this happens, the starter is ready to be used for your first loaf.

But the feeding continues. The longer you use and feed the starter, the stronger and more full with flavor it becomes. If you bake often (more than once or twice a week), it’s a good idea to store the starter at room temperature and refresh it daily using the same method from step 3. I also recommend doing this for the first couple of weeks to train the starter well before storing it in the refrigerator even if you decide to use it less frequently.

When storing in the refrigerator, give the starter some time before using it in your baking: at least a day before you want to bake bread, take the starter out of the fridge and refresh it according to the instructions in step 3.

Treat your sourdough culture well and it will outlive you and provide food for generations to come.

Now, if you still haven’t made your starter, get to work.

And then, next week, we’ll bake some bread.

Comments (11)

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  1. I am on day 3 and not only there are bubbles but also there is separated liquid !
    I was shocked but I stirred it and feed as you said here. But I am not sure what will be happening tomorrow..?
    Am I right?

  2. Hi, I was reading the sourdough starter tutorial. So first Sept is 50grams of bread flour and 50grams of whole wheat with 100 grams of water. Do I leave this for two days without feeding. Or do I feed it the amount on the second day. A little confused
    Thank you

  3. tried 4 3 yrs to make sour dough to make bred. This wk I made it in 3 days ,imagine !
    The rye 1/2 c & 1 c h2o tablespoon raisens,,onite it was running off the table on my floor
    Foaming ! thats tues nite Start, thurs nite on the floor
    3 yrs tried to make sourdough no way–this wk i used rain water,rye 1/2 c 1 c rainwater
    thurs nite refresh same way But added tab raisens ,2 hrs later its boiled out of qt container
    and on the floor . fri nite going to do it again refresh same way Then make bred!
    The secret is rain water,,cleanses the air at 80 degrees ,bacillis was in the rain water
    along with some good bacteria in the raisens ill let u guys no in a few days

  4. Hi Jarkko,
    If am correct from day three on till day 7 every day you ONLY take 25-30gram of the active starter (from day three mixed with 200g water and 200 gram meal,) for the new starter? Am i not spilling the 200 gram flour mixture every day then?
    DAY 3 Starter (200 gram water, 200 gram mixed flour)
    DAY 4 Starter (200 gram water, 200 gram mixed flour) – extract 25/30 gram from the starter and add 200 gram and 200 gram NEW mixed flour for the NEW starter.
    DAY 5 Starter (200 gram water, 200 gram mixed flour) – extract 25/30 gram from the starter and add 200 gram and 200 gram NEW mixed flour for the NEW starter.
    DAY 6 Starter (200 gram water, 200 gram mixed flour) – extract 25/30 gram from the starter and add 200 gram and 200 gram NEW mixed flour for the NEW starter.
    7 Bake the bread with the starter
    If you only bake once a week you can save it in the refrigator, and so you only have to refresh once before baking?
    Hope to hear from you.

  5. so. I take the finished sourdough out of the fridg refresh using say one part sourdough to two parts new flour and two parts water. Now I leave this mixture out for 10 hours and use it for bread making. My recipe says put a cup of flour and a cup of water in the cup of sourdough and set in a warm place overnight. That makes twice refreshing. Is that right? Or is it ready after the first 10 hours

    1. Actually, the answer is: it depends 🙂
      Doing two refreshes after taking the starter out of the fridge never hurts, but it might not be necessary. It all depends on how active your starter is.
      If your starter is like mine, it will be bubbling vigorously after just one refresh. In that case, just use it at that point. It will work very well. If it’s not active after the first refresh, go ahead and do another one. 🙂
      After some experimentation, this will feel natural, so I’d say try both ways and see if you notice a difference.

  6. I’m on day 7 at the moment and I’ve followed this recipe every step of the way, but I have one dilemma: if only a big table spoon of the original starter is to be kept and the rest thrown away, when is it the best time to use the starter for bread making? After 12 hours of the feeding or more?

    1. Hi Liana! Sounds like you’re doing great!
      The best time to use the starter depends on your starter’s activity and also the flavor you are after (for a stronger sourdough flavor, you can use it a bit later than if you are looking for a milder version).
      In general, however, I like to use the starter about 8-10 hours after the refreshment.
      Once your starter is good (at day 7, I think it probably already is), you can also make things easier for you by refreshing the starter and then placing it in the refrigerator. Then, all you need to do is to take the starter out of the fridge about 10 hours before you want to mix your final dough and refresh it…
      On the other hand, if you want to store your starter at room temperature (to get a milder, sweeter taste, for example), you can do it so that you always refresh the starter in the morning (once a day) and then, the night before you want to mix your dough (again 8-10 hours before), take the one to two table spoons of starter and refresh it for bread making.
      Both work. I’ve been doing the latter version more, but now, I’m moving towards the direction of the first one as it makes things a bit easier. 🙂
      I hope this helps! Happy baking!

  7. Hi Jarkko,
    I have a doubt: you just feed your starter once a day?
    Congrats for your great work!!

    1. Hi Catarina!
      Yes, I do it once a day. I’ve heard there are some bakers doing refreshes twice a day, but that would be too much work for a home baker like myself… And I’m not quite sure about what the benefits for doing that would be.
      Thanks for your kind words, and happy baking!

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