How to Make Sourdough Starter within 7 Days

how to make sourdough starter featured

Sourdough starter is just a mixture of only two ingredients, ie. the flour and water, but we can eventually use it for leaven sourdough bread and more.

The whole process of making sourdough starter is pretty simple. Within 7 days, you start with mixing your flour and water, observe it, discard some of the mature starter, feed it with new flour and water for refreshment, then repeat the job discarding and feeding, and finally you will get a sourdough starter made in your own kitchen.

In the following, I am going to share with you every single detail and make this job easy.

Let’s dive right in.

What We Need for Making Sourdough Starter

  • 100g organic stone ground wholemeal flour
  • 100g water
  • 3/4L glass jar
  • A breathable cover or a lid (such as a clean tea towel or coffee filter)
  • A digital kitchen scale
  • A whisk
  • A spatula
  • Cooking thermometer if necessary

Steps to Make Sourdough Starter

Day 1. Make the Mixture of Flour and Water

On the first day, what we need to do is quite simple. First mix 100g flour and 100g warm water (27-28°C. If you want some accuracy, now is the time to use the thermometer to help you with it.) in the glass jar.

The container holding the mixture should be non-reactive. Because the sourdough starter is acidic and it will react with some material. So I would strongly recommend you choose the glass-material container.

Then use the whisk to stir them vigorously to incorporate air. If it feels too thick, we can add a little more water. In the end, the mixture should be like a thick milkshake.

mix flour and water

Finally, cover the glass jar with a breathable cover or lid and place the mixture in a warm place in your kitchen for 24 hours. If the room temperature is not as warm as you like, you can try putting it in your oven which is turned off but with light on, for a few hours. Microwave is quite OK for this job, but please remember to also turn it off, but turn the light on, and its door should not be closed entirely.

Besides, the place where you place your mixture should not be with other cultured food. This is because the cultured food will probably cross over with your sourdough starter and protect it from catching wild yeast. We know that no wild yeast, no sourdough starter.

Some readers of mine have also asked about if it is OK to use an airtight container. Honestly, the airtight works. But you just need to notice that the container should be large enough for the starter to grow. Or it may burst out.

Then we are going to talk about the only but most important two ingredients, the flour and water.

Honestly, you don’t need to use some fancy water for the sourdough starter. Spring water, bottled water, or some other is OK, but tap water can work, too. I prefer tap water because it is cheap and easy to access.

But if your tap water is with too much chlorine, chloramine, and fluoride, which are the most common elements to sanitize tap water and will cause the sourdough starter to die, you have to do something extra to make it qualified for the sourdough starter.

For chlorine, you can leave some tap water in a bowl overnight and it will evaporate from the water. If you want to speed up the process, you can just boil the tap water for 5 minutes.

For chloramine and fluoride, they will not get out of the tap water by themselves. But we can use the kitchen water filtration system to remove them.

Then it is about the flour. There are many kinds of flour,rye flour, whole wheat flour, unbleached all-purpose flour, bleached all-purpose flour, etc. Which one is the best for making sourdough starter? How does sourdough starter made from different flour impact the bread baking?

What is the Best Flour for Making Sourdough Starter?

First, the conclusion. Based on my experiences, the differences in the starting flour for sourdough starter have an effect on the starter and the final bread texture, but little impact on baking bread taste and aroma.

So my opinion is that you can choose any common flour for your sourdough starter. In this guide, as you can see above, I choose the organic stone ground wholemeal flour.

flour types

If you want to know more information about the relationship between different flour and sourdough starters, you can keep reading in the following.

The sourdough starter texture of unbleached and bleached all-purpose flours is thinner with no large trapped bubbles compared to rye and whole wheat flour.

For the bread baking with different sourdough starter, unbleached and bleached all-purpose flour sourdough starter helps the bread with a dense texture with several tunnel-like large air pockets, while the rye and whole-wheat flour sourdough starter leads to the bread fluffier with no large collapsed large air pockets.

However, some people prefer rye and whole wheat flour. Whole wheat and rye flours provide more nutrients for the starter to ferment more actively. But when we maintain the starter made of rye flour, it would be a little easier than whole wheat.

Besides, even though rye and whole wheat flour have similar amounts of increased fiber and nutrients, because of rye with lower gluten content, it’s much easier to stir. Surely, it would be a big problem when we make the sourdough starter, because the amount of flour used is quite small.

A Practical Tip for More Acidic Sourdough Starter

If you want to bake your bread more acidic, an acidic sourdough starter would be helpful. When you make sourdough starter, you can use a higher ratio of flour to water. Basically, we choose the 1:1 ratio. For more acidic bread baking, you can mix the flour and water at a ratio of like 1.5:1. This is because a drier environment will be very helpful to produce acetic acid more abundantly.

The second one is to use whole grain flours. Because acid-producing bacteria love whole grain flour.

Day 2. Feed Sourdough Starter for the First Time

If lucky, after 24-hour fermentation, you will see some bubbles in it. If not, there is no need to worry about it. It happens because of the wheat type and temperature factors. You will see the bubble in about another 12-24 hours.

Anyway, at this time, what we need to do is feed the sourdough starter.

How to Feed a Sourdough Starter?

Feeding is more about providing the bacteria in the starter with food – the fresh flour and water. So they can grow to make the starter good enough for baking bread. The operation is quite simple and here are the how-to steps.

Step 1. Remove half of the sourdough starter and save it into a bowl or some other containers. Please do not throw away the discard, because we can cook it into some delicacy. You can check the details in another part of the sourdough starter discard recipe below.

You may wonder why discard half of the starter. The reason is that we discard the starter at some point, so there would be enough space for the starter to grow and not overflow out of the glass jar. More importantly, we can put in new goods, so the yeast can have enough food to eat.

Step 2. Add 50g flour and 50g warm water (27-28°C) into the rest of the sourdough starter. And then use the spatula to mix them well.

The flour type should be the same as the initial type. Surely, you can turn to another type of flour. But, after feeding your sourdough starter with different types of flour, your starter would be switched to a new type.

About how much flour and water to feed. Basically, I recommend you feed the starter following a 1:1:1 ratio by weight. For example, if you have 50g of starter left in the jar, feed it with another 50g flour and 50g water. Please make full use of the kitchen scale for this job.

Step 3. Then place the glass jar somewhere that is away from other cultured food. Wait for another 12-24 hours until the next time when we need to feed it.

Day 3-6. Repeat the Sourdough Starter Feeding and Observe It

After another 24 hours, on day 3, you will see your sourdough starter surface full of bubbles and with a pleasant aroma. Now it is time to feed the starter again. You just need to follow the steps on day 2. And follow the same steps for day 4, 5, and 6.

This would be very easy. Just please remember to observe your sourdough starter after some intervals of time to check if it needs feeding.

Day 7. Sourdough Starter is Ready

On day 7, your sourdough starter should be ready for use. To check if it is OK, you can do the float test for it. It is simple to do. You use the spatula to get a small part of the starter and put it in a glass bottle filled with water. If the starter floats, mostly, it turns out that the starter is ready.

Tip: On rare occasions, if you find that your starter smells or tastes bad, or that the bread it produces is not very pleasant. This means that the bacteria that has stayed in your starter is not the right kind, and there is not enough lactic acid produced to get out of the unuseful organisms. You will need to discard this starter and start over.

However, after you get the starter ready, the work has not finished yet. Then we need to figure out how to store and maintain the sourdough starter to use in the future.

How to Store and Maintain Sourdough Starter

Even though making a sourdough starter is not very hard, starting it over would be my last thing that I will do. So how to store it for a period that we want appears important.

Depending on the frequency of using the sourdough starter, I have 4 different methods to store it.

Method 1. Store it at room temperature

If you bake often, like a few times a week, you can simply store it at room temperature. Because at room temperature the fermentation will not stop, and the starter will be always active and ready to use faster. However, you need to remember to feed the starter one to two times a day, depending on how quickly it rises and falls. It would be like how we are doing on day 2-6 when we make sourdough starter.

Method 2. Store it in refrigerator

If you don’t bake that often, like one or two times a month, you can store your starter in the fridge covered with a breathable lid. You can save the starter in the fridge for a few months. This is because when the temperature is getting cold, the yeast will be active at a low level and the fermentation becomes slow.

In this situation, you’ll only need to feed it about once a week. To feed it, if you are not going to use it for baking, you can simply feed it cold and then put it back into the fridge. If you are planning to use it for baking, you need to first put the starter back to room temperature, and then feed it. By that, you can reactivate the starter to the normal level which is qualified for baking.

Method 3. Dry it

If you want to store the sourdough starter for months, or even years, making the sourdough dry is a great option. And here is how,

spread sourdough starter on parchment

Step1. Feed the sourdough starter first, then let it rest until it becomes bubbly.

Step 2. Spread it out on a piece of parchment, as thinly as possible. You can use the spatula to help you with it.

Step 3. Dry it naturally until it is crisp and you can easily peel it down from the parchment.

Step 4. Break the dry starter into pieces and store them in an airtight glass jar.

Step 5. When you are going to use it for baking bread, first mix the dry pieces with warm water until they dissolve, then feed it with flour. Observe it, and when it gets bubbles it is time to feed it again. You can feed it daily until it is revived.

Method 4. Freeze it

If you want to store the sourdough starter for like a year, the other way of mine is to freeze it. You can simply transfer it into an ice cube tray and place in the freezer until it is frozen.

To bring back the frozen starter to active again, place the cube into a glass jar and allow it to melt. Once fully melted, feed it with warm water and flour. Feed it daily until it is back to normal.

3 Sourdough Starter Discard Recipe

1. Golden Sourdough Starter Waffles


  • 460g buttermilk
  • 55g water (used to adjust batter consistency)
  • 110g butter, melted and cooled
  • 100g ripe sourdough starter
  • 250g all-purpose flour, einkorn flour, or a mix of all-purpose and whole wheat
  • 15g sugar
  • 2 eggs
  • 5g sea salt
  • 5g baking soda

2. Sourdough Starter Pancakes


  • 2 eggs
  • 245g whole milk
  • 60g Greek yogurt (optional)
  • 250g sourdough starter
  • 5g vanilla
  • 180g all-purpose, einkorn, or a mix of all-purpose and whole wheat, flour
  • 5g baking soda
  • 5g baking powder
  • 5g sea salt
  • 50g granulated sugar
  • 60g melted butter

3. Baker’s Banana Bread


  • 240g spelt, whole wheat, einkorn, all-purpose flour, or a mix
  • 5g baking soda
  • 5g sea salt
  • 125g chopped walnuts
  • 125g butter, at room temperature
  • 100g brown sugar
  • 2 eggs
  • 125g sourdough starter
  • 42g raw honey
  • 4 super ripe and mashed bananas
  • 30g extra virgin olive oil
  • 5g vanilla
  • zest of 1 lemon

What to Do Next?

Now you get how to make sourdough starter. Go to your kitchen and make one on your own. And then use it to bake sourdough bread, sourdough sandwich bread, no-knead sourdough bagels, and more.

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