What Does Acid Do to Bread Dough: Understanding the Role of Acid in Baking

Acids play a crucial role in bread-making by influencing various aspects of the dough, fermentation process, texture, and flavor of the final bread. This article aims to provide a brief overview of how acid influences various aspects of bread-making.

In bread dough, the acidity that develops naturally through fermentation, as well as the use of acidic ingredients contribute to:

• Strengthening the gluten structure of the dough,
• Formation of a rich flavor profile,
• Improving nutrient profile,
• Prolonging the shelf life of baked goods.

The acidity in the dough naturally develops during fermentation, as a result of the activity of lactic acid bacteria, which produce lactic acid and acetic acid. Adding preferments to the bread dough, such as sourdough starter, further enhances its acidity.

In bread dough preparation, additional commonly used ingredients that contribute to acidity are ascorbic acid, citric acid, vinegar, and fermented dairy products such as yogurt or buttermilk.

Whole wheat bread slices on a cuttig board

How Do Acids Affect Bread Dough?

1. Improving crust and crumb structure

Acids play a role in strengthening and stabilizing the gluten network in bread dough, which gives structure to the bread. However, too much acidity can cause the dough to become too soft and lose its structure, resulting in inadequate rising during baking.

Acidity provided by preferments, especially in rye bread, helps balance excessive enzyme activity, preventing a sticky crust.

2. Influencing the taste of bread

The presence of acids in bread contributes to its overall flavor profile, adding a tangy or sour taste. During the fermentation process, lactic acid and acetic acid are produced. Lactic acid contributes a milder, buttery, and slightly tangy flavor, while acetic acid adds a stronger, vinegary taste.


Sourdough bread is best not sliced fresh out of the oven but should be allowed to cool completely for a few hours. During this time, the flavors further develop in the loaf and its acidity increases.

3. Improving the nutrition profile

in whole wheat flour, the bran contains phytic acid, which inhibits mineral absorption in our bodies. However, using a sourdough starter helps counteract the effects of phytic acid, aiding the absorption of minerals like zinc, magnesium, copper, and iron when we consume bread.

4. Prolonging the shelf life

Acidic environments are unfavorable for the growth of harmful microorganisms. By incorporating acid into the bread dough, either through natural fermentation or by adding acidic ingredients, the bread’s shelf life can be extended as it becomes less prone to mold and spoilage.

How to extend the shelf life of bread

The Formation of Acids During Dough Fermentation

Beneficial acids are created during the prolonged fermentation process, thanks to the work of lactic acid bacteria. To shorten fermentation time, preferments like sourdough starters can be added since they already contain organic acids.

The temperature at which the dough ferments influences the speed of fermentation and acid formation. Temperatures between 4 and 12°C (39 and 54°F) favor the production of stronger acetic acid, while higher temperatures between 12 and 30°C (54 and 86°F) promote the production of milder lactic acid.

Temperature also impacts acid formation in sourdough starters. Keeping a starter at room temperature and feeding it daily leads to more lactic acid production while refrigerating the starter and feeding it weekly results in a dominance of acetic acid.


The water content of the sourdough starter can determine the types of acids that will dominate. With higher hydration, a more liquid starter will contain more lactic acid, whereas a stiffer starter will have more acetic acid.

In dough made solely with commercial yeast, the fermentation process occurs more rapidly than in dough made with a sourdough starter containing wild yeast cultures, resulting in less acidic compounds being produced in the dough. Consequently, less acidic compounds are produced in the dough. However, it is possible to combine both baker’s yeast and sourdough starter to create the dough.

By reducing the amount of yeast used, we can prolong the fermentation time of the dough, allowing for increased acid development. In the warm summer months, we can reduce acid formation by slightly increasing the amount of salt added to the dough.

What Acids Can We Add to Bread Dough?

Acids are considered dough conditioners that enhance the quality of bread in various ways.

Ascorbic acid, commonly known as vitamin C, is frequently added to commercially available breads. It helps strengthen the gluten structure in doughs with a short fermentation time. Bakers use ascorbic acid in small quantities, and since it breaks down during baking, it does not affect the bread’s taste. Citric acid or vinegar can also be added to increase the acidity of the bread.

Fermented dairy products such as cultured buttermilk, yogurt, kefir, acid whey or sour cream enhance the gluten structure of the dough and contribute to a rich flavor in the bread. These dairy products also contain lactose and fats, which further enhance the overall taste and texture of bakery products.


In the case of quick bread, which relies on chemical leavening agents instead of yeast, baking soda is commonly used. Activating baking soda requires the addition of an acidic ingredient, often cultured buttermilk.

Final Thoughts

In conclusion, acid is an essential element in bread dough, impacting its structure, nutrition profile, flavor, and shelf life.

Incorporating different acidic ingredients allows for experimentation, creativity, and customization in bread-making.



My name is Debora, the founder of My Delicious Sweets, and a qualified confectioner with broad experience in the confectionery industry. On my blog, I will share important, interesting, and fun facts about food, along with some of my favorite recipes.

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