What is a sourdough starter?

What is a Sourdough Starter?

Sourdough: Living Bread

Starter is a combination of flour, water, wild yeast, and lactic acid bacteria. The yeast and microbes originally come from the soil and the surface of the wheat that is made into flour then fermented. After the microorganisms have colonized the flour and water mixture, the sourdough starter can be kept and maintained indefinitely. It is also called “leaven”.

An established sourdough starter is alive with these cultures and yeasts, you will keep it alive by regularly feeding and using or discarding any unused starter. You can feed and discard as often as daily or as seldom as weekly (if you plan to keep your starter in the refrigerator).

Benefits of Sourdough

The long fermentation process of sourdough as well as the way the lactic acid bacteria breaks down gluten proteins during fermentation makes a true sourdough bread more digestible.

For many people who have a gluten sensitivity, they find that they can enjoy bread again! You can learn more about my story here.

The Continuous Cycle of Sourdough

The key part of caring for a sourdough starter is the continuous cycle of using or discarding and feeding.

A small portion of the old batch is always kept to initiate the next batch of starter once it is fed.

After that small portion of sourdough starter is fed with flour and water, it is left at room temperature to become active for 6-12 hours (the variation in timing is due to water and room temperature in changing seasons).

Once active, the bulk is used in a recipe which leaves a small remainder to feed to start the process again.

If you don’t use your sourdough starter when its active, after several hours it will completely collapse and become inactive as the yeast activity is too depleted. This stage is called discard. Once your starter is in this stage, you will need to discard 90% of the sourdough starter. That 90% can be thrown out or can be saved in the fridge for up to 4 weeks as emergency backup or to use in a delicious sourdough discard recipe like Sourdough Discard Crackers or Sourdough Graham Crackers. Then, the 10% left is fed and left at room temperature to become active as the cycle begins again!

See the video at the bottom of the page to see this process called refreshing (discarding and feeding) which is essential to care for your starter and create an active sourdough starter to use in bread.

Now that you know a little bit about what a sourdough starter is, how do you get one?

A sourdough starter can be obtained in two ways.

First, someone can give a portion of their sourdough starter via gift or purchase.

I sometimes sell portions of my starter and I give one to every student who takes a class. Other online retailers like Breadtopia or Cultures for Health sell sourdough starters as well!

Second, you can make one at home. The process takes about 7 days but will give you a better understanding of sourdough! See this post for how to make yours: How to Make a Sourdough Starter.

Refreshing a Sourdough Starter

See the video below to learn the basics of sourdough starter 101 and how to care for a sourdough starter by refreshing it. Refreshing is done either once per day if the starter is kept at room temperature or at least once a week if the starter is kept in the fridge to keep the starter alive and healthy.

This step must be done 8-12 hours  in advance of each time you plan to use it in a bread recipe. I usually mix bread dough in the morning so I do this step before bed and let the starter sit out at room temp overnight.

This information with illustrations, visuals, and more to get you started with sourdough is included in my Sourdough Quick Start Guide. You can find out how to receive a copy here:

About Me

Jenny Prior owns and operates Living Bread Baker, where she teaches sourdough baking and creates recipes to share through her books and website. Her love of cooking, background in teaching special education, and health journey led her to create this business to help share the joy and wonder of sourdough baking with others.

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