What happens when adding yeast to sourdough starter?

In this brief guide, we will answer the question “what happens when adding yeast to sourdough starter?” with an in-depth analysis of the reason which causes the results produced by the addition of yeast to sourdough starter. Moreover, we will also discuss the effect of adding yeast to the sourdough starter on the taste and texture of sourdough.

What happens when adding yeast to a sourdough starter? 

On adding yeast to the sourdough starter, the carbon dioxide content of the sourdough increases. The elevation in carbon dioxide content produced by the added yeast results in a good flavor and soft texture of the bread.

The mechanism that follows in the sourdough starter after the addition of yeast:

The yeast spurs CO2 development to help achieve a rise and give sourdough its signature bubbled texture. Meanwhile, the lactic acid imparts a tangy flavor and breaks down the bran and starches in the flour, which helps to develop the gluten that lends sourdough its lovely chewiness.

Can you mix sourdough with yeast?

Yes, you can mix instant yeast with sourdough. However, the type of flour used does not have much to do with the fermentation activity. The different flours have different protein contents, which impact gluten development.

What does yeast do to sourdough?

Sourdough is a stable culture of lactic acid bacteria and yeast in a mixture of flour and water. The yeast produces gas (carbon dioxide) which leavens the dough, and the lactic acid bacteria produce lactic acid, which contributes flavor in the form of sourness.

Can you add a little yeast to your sourdough starter?

If you want, you can add a little commercial yeast to a starter to boost it. Note that a sourdough starter made with commercial yeast often produces bread with a less distinctive sour flavor than the real thing. After every 24 hours, add a little water and flour to the starter. You should keep the starter in a warm place for a suitable rise.

Is it necessary to add yeast to a sourdough starter?

Traditionally, there is no extra yeast added to a bread dough made with a sourdough starter, though you can add yeast when making an express loaf. Instead, flour and water are left out at room temperature and catch the wild yeast that is present in the air all around us.

Why do some home bakers discard half the sourdough starter?

The primary reason home recipes for starters call for some of it to be discarded is because as the starter is fed (refreshed) with flour and water to keep it alive and active, it continues to grow and expand to a far greater quantity than is practical, especially for home baking.

Is sourdough starter better than yeast?

The sourdough fermentation may reduce the phytate content of bread by 24–50% more than conventional yeast fermentation. Lower phytate levels increase mineral absorption, which is one of the reasons why sourdough bread is more nutritious than conventional bread.

You can read more about sourdough here.

Other FAQs about Yeast which you may be interested in.

How many teaspoons in 1 package of yeast?

How to get rid of yeast taste in bread?

What to do if there is too much yeast in the bread?

Why does the sourdough starter smell like vomit?

The smell of vomit comes from butyric acid that is one of the byproducts of the fermentation reaction. As you leave the sourdough starter unfed for too long, the accumulation of butyric acid imparts a strong and unpleasant smell of vomit.

How long does it take for the sourdough starter to peak?

It takes between 4 and 12 hours for a sourdough starter to reach its peak.

The sourdough starter generally will be at its peak anytime between 4 and 12 hours after feeding.

How much yeast can be added to the sourdough starter?

To help proofing go faster within the homemade sourdough starter, try adding ⅛ teaspoon of instant yeast per cup of flour.

How much yeast can you use in a commercial sourdough starter?

Use as little as 1/4 tsp yeast to get a long rise similar to using sourdough. This will create more complex flavors and gives some hands-off gluten development. 

Or use 1 to 2 1/4 tsp yeast for the dough to double in 1 to 3 hours. (2 1/4 tsp of yeast is equal to one packet.)

Does yeast affect the taste of bread?

One gram of yeast contains 20 billion tiny yeast cells. This can affect the bread by adding a yeasty taste if too much yeast is added to the dough. 

General amounts of yeast are around 1 – 2 % of the flour, by weight.

Too much yeast could cause the dough to go flat by releasing gas before the flour is ready to expand along with the addition of an off-taste.

Conclusion:

In this brief guide, we have answered the question “what happens when adding yeast to sourdough starter?” with an in-depth analysis of the reason which causes the results produced by the addition of yeast to sourdough starter. Moreover, we have also discussed the effect of adding yeast to the sourdough starter on the taste and texture of sourdough.

Citations:

https://www.seriouseats.com/sourdough-starter-science
https://www.cooksillustrated.com/how_tos/13574-for-faster-sourdough-add-yeast
https://www.thespruceeats.com/beginner-basic-sourdough-starter-428067