Sourdough Starter vs Sourdough Discard: What's The Difference?

Sourdough Starter vs Sourdough Discard - are they really different things, or just one of the same? If you're just beginning your sourdough journey by making your own sourdough starter, you might be wondering what sourdough discard is? And whether it's the same as sourdough starter or something completely different? 

It's a question I get asked on a daily basis in my Facebook Group of over 240,000 people.

Sourdough discard is the unfed portion of your sourdough starter that you remove before you add fresh flour and water. Because of it's unfed state, it's not used to bake the delicious bread you know as sourdough, but more often than not, used in sourdough discard recipes.

Now, as with most things related to sourdough, there's always a bit more to it, so if you'd like to know more about the wonder that is sourdough discard, you'll find the answers to all your questions below.

Frequently Asked Questions About Sourdough Discard

Is sourdough discard the same as starter?

Sourdough discard is not exactly the same as the active sourdough starter. The starter is a mixture of flour and water that captures wild yeast and bacteria over time, creating a leavening agent for bread. 

On the other hand, sourdough discard refers to the portion of the starter that is removed and discarded before feeding the remaining starter during regular maintenance. It contains some of the fermented mixture but may not be as active as a fully refreshed starter.

Can sourdough discard be used as starter?

While sourdough discard can't replace an active starter in a recipe that relies on a robust leavening agent, it can be revitalized and used to create a new starter. By feeding the discard with fresh flour and water over a few consecutive feedings, the microbial activity can be restored, eventually turning it into a viable and active sourdough starter.

If using sourdough discard in place of active sourdough starter, you will generally need to use some commercial yeast to add leavening power, unless the starter your discard is from is very mature and you allow extra fermentation time.

What is the point of using sourdough discard?

The use of sourdough discard serves both practical and culinary purposes. Practically, discarding a portion of the starter during regular feedings helps maintain a manageable quantity, preventing the starter from growing excessively. 

Culinary-wise, sourdough discard can be used in various recipes such as pancakes, waffles, muffins, sourdough pasta and quick breads like sourdough banana bread to impart a tangy flavor, reduce food waste, and add complexity of flavor to your baked goods. Remember, you can't use the discard from your homemade sourdough starter for the first 7 days.

You can use sourdough discard in all kinds of sourdough discard recipes, including these no wait sourdough recipes, overnight sourdough discard recipes and sourdough discard recipes that use up a lot of discard.

What happens if you don't discard your sourdough starter?

If you don't discard a portion of your sourdough starter regularly, the quantity of the starter will increase, and it may become impractical to maintain. 

Additionally, the microbial balance within the starter may shift, potentially affecting the flavor and leavening capacity of your sourdough. It becomes very acidic when you don't discard your starter and this can affect gluten development and oven spring.

Regular discard and feeding help keep the starter healthy, vibrant, and ready to contribute to successful and flavorful sourdough bread.

You can read more about why you must discard sourdough starter here.

Does Sourdough Discard have the same benefits of Sourdough Starter?

Technically, sourdough discard has the same benefits as sourdough starter, since they are both wild yeast ferments. In terms of beneficial lactic acid bacteria, natural yeasts acetic acid and colonies of microbes, they are both full of them.

The difference is that because sourdough discard is unfed, and you generally use it in recipes that also have a quick leavening agent added, you don't get the long fermentation benefits of discard like you do when using active sourdough starter.

You can find more information on this topic in this article - are sourdough discard recipes really healthy?

Can You Use Sourdough Discard To Start Another Sourdough Starter?

Technically, yes you can use sourdough discard to start another starter, however I advise against this unless you have a mature sourdough starter that you are wanting to share with family and friends. Then you can portion off a little discard that they can feed.

If you have a young sourdough starter, using the discard to start another sourdough starter is pointless, since then you are using even more flour to essentially feed two immature starters. You're better off using all your resources to create one healthy and active starter, rather than maintaining two starters.

Can sourdough discard be stored for later use?

You can store sourdough discard in the fridge for up to 2 weeks. It's fine to leave it on the counter for up 24 hours, however if you aren't planning to use it straight away it's always better to store it in the fridge.

You can continue to add sourdough starter from different days to the same jar.

Can sourdough discard be frozen for later use?

Absolutely you can freeze sourdough discard for later use. It's best to freeze sourdough discard in small portions (like 50 to 100g) so that you can thaw only what you need for a particular sourdough recipe.

The caveat here is that if you are creating so much sourdough discard that you need to freeze it to keep up with it, I would advise that you need to reduce the amount of flour and water you're feeding your sourdough starter, and thus the overall size of your sourdough starter.

Can I compost sourdough discard?

Yes you can add your sourdough discard to the compost heap. It's a welcome addition to any compost heap because it's teaming with natural microbes.

It is also fine to place into a bokashi bucket. Sourdough discard is also a wonderful fertisiler for indoor and outdoor plants. You can find instructions for using sourdough discard in the garden here.

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