What is a sourdough starter?

Let’s learn the basics of what a sourdough starter is and how to care for it so you can have sourdough success!

Sourdough is Living Bread

The sourdough starter is a living ingredient.

It’s teaming with millions, even billions of microorganisms that perform different functions to rise your bread, create incredible flavor, and make your bread more digestible and healthy.

What is a sourdough starter?

Starter is a combination of flour, water, wild yeast, and lactic acid bacteria. The yeast and microbes from the soil are on the surface of the wheat.

The wheat is made into flour, then when water is added to the flour in the right conditions, the microorganisms colonize the flour and water mixture.

After that happens, you have a sourdough starter! 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).

I cover sourdough starter care, the cycle, benefits and more in the starter 101 section of my Intro. to Sourdough online course.

Benefits of Sourdough

Is sourdough healthy? What are the 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.

How to Refresh a Sourdough Starter

See the video excerpt from below to learn the basics of sourdough starter, including how to care for it by refreshing. Refresh your starter daily if kept at room temperature. If you keep your starter in the fridge, refresh it at least once a week. Regularly refreshing keeps the starter alive and healthy!

You must refresh 8-12 hours before 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 get a copy here.

The Continuous Cycle of Sourdough

How do you take care of a sourdough starter?

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

Always keep a small portion of the old batch to use to start the next batch of starter.

After that small portion 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.

What happens if you don’t use your starter when it’s active?

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 it. 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.

What is sourdough discard?

Sourdough discard is what the starter is called after the yeast and good bacteria have broken down and eaten all the food (the fresh flour you fed it).

This stage looks like a very liquid like mixture with a strong sour smell.

Sourdough discard does not have rising power but it can be useful. Most importantly, you can take a portion, feed it and your starter will become active and healthy again!

How do you get a sourdough starter?

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

You can purchase my batch tested dehydrated sourdough starter here. 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.