How long to ferment sourdough ?

How long to ferment sourdough ?

When preparing sourdough bread, you may have many questions about the technical aspects of this practice. And one point that often comes up is that of fermentation. Sourdough preparation involves fermenting the yeast and lactic acid bacteria contained in the dough. So you may ask : how ferment sourdough? BRO, specialist in the field, tells you all about it in this article.


How long to ferment sourdough ? The answer by BRO

When it comes to making sourdough bread or panettone, a number of questions can arise. One of the questions that comes up most often is that of fermentation time. To answer this question, we need to look at the sourdough fermentation process.

To ferment sourdough, you need to prepare it in the right conditions. Here are the steps involved:

  • Mix 50 grams of flour and milliliters of water in a jar. Once you’ve stirred the mixture and obtained a thick paste, you can leave it to rest at room temperature, covered with a clean cloth.
  • Repeat this process every day for the next six days.

This process will then allow your sourdough to ferment, thanks in particular to the action of lactic acid bacteria and yeast. So, if you were wondering how long to ferment sourdough, you now know that the duration of fermentation actually corresponds to the preparation time of your sourdough, i.e. seven days.

Over the course of these seven days, you may see the first signs of fermentation activity appear earlier, in the form of bubbles forming in the dough.


Lactic acid bacteria and yeast during fermentation

Now that you know how long to ferment sourdough it takes, you may be wondering how this process is triggered. In reality, fermentation is due to the combined action of lactic acid bacteria and yeast.

During the dough’s working phase, lactic acid bacteria and yeast ferment the sugars present. This results in the production of CO2 (carbon dioxide). Without the presence of lactic acid bacteria and yeast, sourdough fermentation is impossible.


So, if you were wondering how long to ferment sourdough, you now know that the duration is directly linked to your sourdough preparation process. BRO advises you to wait seven days for your sourdough to ferment ideally. However, the first signs of activity can be observed earlier, by watching for the appearance of bubbles in the dough.

Want to find out more about the sourdough-making process? Discover our page dedicated to training in the use of this product!

Guillaume Etlin
This article is written by

Guillaume Etlin

Parisian baker chef, bakeries owner, and sourdough bread and panettone expert.  Crafting sourdough panettone all year round, his bakeries continue to thrive, attracting customers even during the off-season. Also, they supply sourdough bread to exclusive hotels and restaurants, including those with Michelin stars.

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