11 Tips on How to Make Sourdough Less Sour
Completely removing the sourness from your sourdough is nearly impossible, but we can make it less perceptible. To do this we must accomplish one or a combination of the following goals with your starter and dough:
- Minimize the production of lactic acid and acetic acid by bacteria, especially acetic acid;
- Decrease bacterial activity;
- Increase yeast activity.
Acetic acid, a main component of vinegar, contributes to the sharp, mouth puckering tang in sourdough breads. By decreasing the metabolic and reproductive activity of sourdough bacteria, you can minimize the amount of bacterial acids produced in your sourdough.
Further, by encouraging sourdough yeast to reproduce and expel gas (carbon dioxide), your sourdough may become less sour and tangy. The basic principles are:
- The more active your yeast, the faster your dough rises;
- The faster your dough rises, the sooner you can bake your dough;
- The sooner you bake your dough, the less time bacteria has to generate acids.
To achieve the above objectives, we must also avert bacteria from producing acetic acid which sharply inhibits yeast activity.
Without further ado, below are 11 tips on how to make your sourdough less sour:
1. Feed your starter more frequently
By feeding your starter more frequently, the bacterial acids in your starter becomes less concentrated and more diluted. As a result, the overall sourness of your starter is reduced.
Moreover, sourdough bacteria generally do not adapt to environmental changes as quickly as sourdough yeast, so feeding your starter more often gives yeast a head start in growth.
2. Rest your starter at cooler temperatures and decrease the hydration of your starter
Generally speaking, sourdough-related microorganisms are more active at higher temperatures and hydration. (Hydration refers to the ratio of water to flour.) Thus, decreasing the temperature and hydration of your starter reduces the activity of bacteria and yeast.
But wait? Isn’t our goal to increase yeast activity, not hinder it? In short, yes. However, when decreasing the temperature and hydration of your starter, in conjunction with frequent feedings of your starter, yeast activity will fare better than bacterial activity.
3. Remove the hooch
When your starter is chilled in excess or ferments too quickly, a translucent, liquied substance called “hooch” may appear in your starter. This substance is a byproduct of sourdough yeast, comprising mostly of water and ethanol (alcohol). Some species of bacteria can metabolize ethanol and discharge acetic acid as a result.
4. Avoid stirring your starter during its resting period
Some species of acetic acid bacteria require oxygen to sustain life. By stirring and therefore oxygenating and redistributing nutrients in your starter, you provide such bacteria the opportunity to use oxygen and metabolize ethanol (a byproduct of yeast). The result? A greater yield of acetic acid.
5. Use your starter before its “peak”
The peak of a preferment (dough fermented in advance) refers to the point at which the preferment begins to deflate, caused by excess (bacterial) acids and gluten degradation.
By feeding your starter before its peak and/or incorporating your “pre-peaked” starter into your final dough, the sourness of your sourdough will be reduced.
6. Use flour with less ash content, primarily white wheat flour
Ash content refers to the mineral content of flour, mostly derived from the bran or outer layer of the grain kernel. In wheat the outer layer of the grain kernel contains sugars called pentosans. These sugars are metabolized by heterofermentative bacteria, which expel carbon dioxide, lactic acid, and acetic acid as a byproduct. In brief, the greater amount of pentosans in the flour, the greater the risk that bacteria will produce acetic acid.
7. Avoid retardation (chilling your dough) and punch downs (degassing your proofed dough)
The longer your dough ferments, the more acids bacteria produce. The more acids produced, the more sour your loaf. Therefore, to minimize the tang in your sourdough it’s advised that you skip chilling and degassing your dough during bulk fermentation (first rise) and proofing (final rise).
8. Add greater amounts of your starter to your final dough mix
This may sound counter-intuitive but it works under one condition: Your starter is well populated with yeast. If this condition is fulfilled, incorporating greater amounts of your starter into your final dough results in faster rising and less time for bacteria to generate acids.
9. Add commercial or baker’s yeast to your final dough mix
Commercial yeast is an umbrella term for industrial yeast, which includes fresh or cake yeast, active dry yeast, and instant yeast. Their primary purpose is to inflate dough with carbon dioxide. Because they are bred to do this effectively, adding as little as a pinch of commercial yeast to your final dough mix may significantly reduce the time for your dough to rise.
10. Rest your dough at cooler temperatures
Bacteria and yeast are generally less active at cooler temperatures. Therefore, it’s advised that you increase the amount of starter mixed into your dough to shorten its rising period (under the condition that your starter is well populated with yeast).
11. Add baking soda (sodium bicarbonate) to your final dough mix
Baking soda is an alkaline capable of neutralizing acids. When incorporated into your dough in negligible amounts (e.g., 1g / 0.04oz per 1kg / 35oz dough), the sourness of your sourdough may become less perceptible.
1: All About Sour. Sourdough Home.
2: Chapter 5: Bacterial Fermentations. Food and Agriculture Organization of the United Nations.
3: Is It Possible to Reduce Sourness in My Bread. The Fresh Loaf.
4: Lactic Acid Fermentation in Sourdough. The Fresh Loaf.
5: Tips for Manipulating the Sourness of Your Sourdough. Cultures for Health.
6: Very Liquid Sourdough. The Fresh Loaf.
7: What factors affect microbial growth in sourdough? Darrell Greenwood.
Author: Zita (bakingbadly)
Published: September 19th, 2013
Last Modified: August 18th, 2014