I love sourdough, always have. Growing up in Europe and the San Francisco Bay Area meant that I was always around delicious bread. When I moved away, I realized that good bread was not always the norm and I would need to learn to bake it myself if I wanted it readily available. Enter: Sourdough. I learned how to make a sourdough starter and never looked back. This is my beginner guide for how to make a sourdough starter.
When I first discovered how to make a sourdough starter and then started baking with it, I knew I had finally found the bread that my dreams were made of. Airy, light, crunchy, crispy and utterly delicious. It is the perfect bread to dip in soup or to eat toasted with a schmear of butter. I want you to be able to eat amazing bread too and oftentimes that means purchasing sourdough starter, getting some from a friend or making your own.



Science Behind A Sourdough Starter

A sourdough starter is a community of bacteria and wild yeast in a symbiotic relationship used to raise dough.
Bacteria acidifies the dough and wild yeasts leaven (or raise) the dough through the production of carbon dioxide. Fresh flour is their food. Wild yeast turns the flour into carbon dioxide gas bubbles and more yeast. Bacteria turns the flour into sugar that the yeast feeds on. It also produces tangy acids and more bacteria. Both the bacteria and wild yeast contribute different flavors to the bread and give it properties that keep bread fresh longer and are good for the gut.
Fermentation Cycle of Sourdough:
Sourdough works through a regular series of feeding/refreshing a culture of starter with fresh flour and water, typically daily or weekly. You will take a small amount of ripe or over-ripe starter and “feed it” with a ratio of fresh flour and water. Mark your jar so you can easily watch the fermentation process. The starter will rise as the yeast increases and fall when the yeast run out of food. Take a small percentage of the over-ripe starter to feed fresh flour and water, and discard the majority of the over-ripe starter. This starts the fermentation cycle over again. Normally a sourdough starter should be fed the same amount and at the same time every day (or every week if you keep it in the refrigerator). You can perform the refreshing/feeding cycle once or twice per day depending on how often you want to bake.
Being observant, giving a starter room to grow, keeping an 80 degree F temperature and refreshing daily creates a good environment for a sourdough starter to grow. A healthy sourdough starter means great bread.

To make your own sourdough starter you will need:
1. A kitchen scale: Most sourdough recipes use measurements based on weight instead of volume. Investing in a good kitchen scale will produce more consistent results.
2. 2.5 lbs whole wheat flour (or rye flour): Wild yeast are more attracted to whole grains, so it’s important to mix some whole wheat flour in with the all purpose flour when creating a starter. Wild yeast is particularly attracted to rye flour, so using rye flour when first making the starter is also a good way to make this process faster.
3. 2.5 lbs white all purpose flour: Having a balance of whole wheat and white flour in your starter gives you the best of both worlds. Whole grains produce increased yeast activity and white flour increases extensibility and helps promote a balanced flavor.
4. Distilled or bottled water : Using filtered or bottled water is important when creating a sourdough starter. Tap water will sometimes have small amounts of chlorine or chloramine in it. This is not good for creating a sourdough starter. Once you’ve established your starter (meaning it is predictably rising/falling/floating in water at peak), you can try switching over to tap water (when you are ready to make the switch, save a little bit of your starter beforehand – just in case it is not ready, in which case you won’t need to start over).
5. 2 wide-mouth jars and rubber band: I like a wide-mouth mason jar that is clear on the outside, wide enough to stick your hand in and easy to mark with a rubber band.
6. A thermometer: Proper temperature is critical for best results. Use a thermometer to take the temperature of your starter. Wild yeast and bacteria are most active around 80 degrees F. Try to keep your starter in a warm place and use warm water as needed to increase the temperature of the starter when feeding.
7. A rubber spatula: This is optional but I like using one to stir down my starter and get all the excess off the sides. It makes it easier to mix thoroughly and see the rise take place. make sure the starter is all mixed thoroughly.
8. My sourdough starter worksheet below: If having a paper copy is helpful, print out my sourdough starter worksheet at the end of this post. This gives you all the information you need to make a sourdough starter and has a place to take notes so you can remember when you fed the starter, how it’s acting and anything else that will help you on your journey.
How to Create a Sourdough Starter

A Few Helpful Hints
- Creating a sourdough starter from scratch can take anywhere from 1 week to 3 weeks. The yeast and bacteria from the flour and your environment need to work together to create a symbiotic relationship. This takes time. Don’t worry if you are not seeing a rise right away. Stay patient. Just keep feeding!
- Temperature is very important. Keeping your starter at a constant 80 degree temperature (check it to make sure) will help speed up the process of creating your starter and will produce many yeast and bacteria in your starter. I use a home dough proofer to help maintain my temperature.
- Throw away the “discard” during the weeks you are building your sourdough starter. This discard is not good to eat because it’s full of excess yeast and bacteria. Once your starter is predictably rising and falling it’s okay to start using it in discard recipes.
- Once your starter is predictably rising and falling, you can change up your feeding schedule to fit your life. My typical feeding schedule is 10 grams of starter, 50 grams of all purpose or bread flour (you don’t have to use whole wheat or rye anymore) and 50 grams of tap water, refreshing once a day.



Sourdough Starters are Resilient! If you forget to feed it one day, don’t worry. Just feed it when you remember. In most cases it will come right back.
Day 1: First 24 hours
- Place a clean mason jar on a digital scale. Tare (zero) the scale.
- Add 100 grams flour (50 grams of whole wheat flour and 50 grams all purpose flour) and 125 grams warm filtered (bottleded or distilled) water to the jar. Stir the starter, mixing completely and using a spatula to scrape down the sides of the jar.
- Put a rubber band around the jar and mark where the starter is.
- Lightly cover the top of the jar with a loose lid, plastic wrap or towel.
- Set in a dark, warm place for 24 hours.


Day 2: Second 24 hours
- Place your second mason jar on a digital scale. Tare the scale.
- Take the lid off your sourdough mixture. It may have some bubbles, it may not. Stir it together.
- Put 75 grams of the mixture into the new jar. Feed it 100 grams flour (50 whole wheat/50 white) and 115 grams water.
- Stir together, scraping down the sides of the jar.
- Mark the jar with your rubber band.
- Lightly cover and set in the same warm spot for 24 hours.
Day 3: Third 24 hours
- Repeat the process from day 2.
- Often by day 2 or 3 you see a burst of activity that dies down around day 3/4. Don’t be discouraged if this happens. The yeast and bacteria are trying to harmonize and they are getting rid of yeast/bacteria that they don’t want.
Day 4 and Onward: until Rising and Falling Predictably
- Place a clean mason jar on a digital scale. Tare the scale.
- Take the lid off your sourdough mixture. It may have some bubbles, it may not. It may be starting to rise or it may not. If it has a thin layer of liquid or hooch, stir it into the starter.
- Put 30 grams of the mixture into the new jar. Feed it 100 grams flour (50 whole wheat/50 white) and 100 grams water.
- Stir together, scraping down the sides of the jar.
- Mark the jar with your rubber band.
- Lightly cover and set in the same warm spot for 24 hours.







How do I know when my sourdough starter is ready to use?
The main thing you are looking for is for the starter to begin rising and falling predictably (at the same time every day). Mark the jar when you feed the starter and watch periodically throughout the day for a rise. You want your starter to rise to about double in size within a day before it is ready to build a levain and make bread. Another key is to check if the ripe starter will float in water. This means that the CO2 has built up enough in the starter that it will leaven bread. To check your starter: feed it. Mark the jar. Wait for the starter to rise and double in size. As soon as it doubles in size, check to see if it floats in water by taking a little spoonful of starter and dropping it into a glass of water. If it floats and is doubling in size, you are ready to bake your first loaf of sourdough bread! Once your starter is ready, continue feeding it on your schedule.


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