Fermented breads emerged as an evolution of Unleavened Bread. While unleavened bread is made without yeast, leavened bread uses fermentation to leaven the dough and create volume and soft texture. Fermentation is a process in which yeasts, such as Saccharomyces cerevisiae, consume the sugars present in dough and produce carbon dioxide and alcohol as byproducts. Carbon dioxide is responsible for the rise of the dough, resulting in soft, leavened breads.
The process of fermenting dough consists of cultivating yeast in the flour and using this culture to produce leavened breads. This yeast culture is known as a levain, masa madre or sourdough starter and you can learv how to make your own in the article All About Sourdough Starters.
Since the 20th century, industrialized biological yeast has been on the market. It is used to facilitate the process of producing bread, it exists in fresh form, with a shelf life of 30 days, and in dry form, with a shelf life of more than 6 months.
Saccharomyces cerevisiae is a single-celled organism often used in the fermentation of bread, beer, and other fermented products.
TYPES OF YEAST AND FERMENTATIONS:
Fresh Yeast: In general, for every 1kg of wheat flour, you can use about 20-30g of fresh yeast. This equates to approximately 2-3%% of the weight of the flour.
Dry Yeast (Instant or Active): For instant dry yeast, you can use about half the amount of fresh yeast. Therefore, for every kg of flour, you can use about 15g of dry yeast.
The proportion of water in both methods varies depending on the moisture of the flour and other ingredients added, but a common proportion is about 60% to 70% of the weight of the flour.
Levain (Masa Madre or Sourdough starter): the levain is a fermented mixture of flour and water and it is associated to natural fermentation. The ratio of flour to water in levain can vary depending on the desired consistency and the specific recipe, however, a common ratio for making levain is to use equal parts flour and water. For a basic bread recipe using Levain, the amount of Levain to be added to the dough is usually close to 30% of the total weight of flour in the recipe and the water is around 70%.
The above proportions are associated with accelerated fermentation time, with up to 8 hours of total fermentation. To obtain a long fermentation, the process can take from 9 to 72 hours. For a long fermentation with Levain, it is recommended to reduce the amount of yeast to 15%. In dry yeast cases, the recommended amount is 1% of the weight of the flour and with fresh yeast, it is necessary to reduce it to 1.5%.
DOUGH FERMENTATION PROCESS:
#1 Adaptation:
When yeasts are added to the growing medium (such as bread dough), they need to adapt to the environmental conditions. During this phase, yeast cells adjust their physiology to deal with new challenges and begin to prepare for reproduction and fermentation. This phase is relatively short and can last from a few minutes to about 1 hour, depending on the temperature and the initial activity of the yeasts.
There is a technique in panification called sponge and dough mixing method that can help in the adaptation process and can develop a more complex, deeper flavor in the bread, as well as contributing to a softer, airier texture. Learn about this technique in our article!
Sometimes, before the sponge, another technique is used in bakingprocess, called autolysis, a process of hydrating the flour with the liquid, before adding the other ingredients (including the yeast). This process is associated with the structured development of gluten and can be found in the article Autolysis, the hydration of sourdough.
#2 Latency:
In the latency phase, yeasts are metabolically active, but cell growth is minimal. At this stage, yeast cells are preparing for cell division and accumulating nutrients and energy needed for the next stage of exponential growth. The latency phase can vary considerably, but generally lasts from 30 minutes to 2 hours. During this time, yeasts are preparing for reproduction and accumulating nutrients and energy.
To help and estimulate the yeast cells to do the cell division, and to obtain a good bread result you need to learn the kneading technique. If this is what you are looking for, access our article From Kneading to Oven.
#3 Bulk Fermentation (the first exponential Growth):
At this stage, yeast cells begin to divide rapidly in an environment rich in nutrients and sugars. The number of yeast cells increases exponentially during this phase, resulting in rapid population proliferation. This is generally the longest phase and can last from 2 to 6 hours, depending on fermentation conditions.
#4 Stationary Phase:
As nutrients are depleted and metabolic products accumulate, yeast cells reach a balance between reproduction and cell death. At this point, the yeast growth rate slows and the cell population remains relatively stable. The stationary phase may begin after the exponential growth period and may last from 1 to 4 hours depending on fermentation conditions.
#5 The next step in your dough fermentation process will happen during the exponential growth, and will depend on the type of bread you are producing. Either you put it in the oven or you manipulate the dough and let it rise again, this process is called Folding the Dough.
Baguette dough, ciabatta dough (the same as Italian bread) and loaf bread are examples of breads that only go through bulk fermentation phase.
The secret for a good bread is time. There are several recipes that work with time measurements such as "let it rise for 30 minutes", but they forget to consider local conditions. Whether the day is humid, hot, dry or cold will have different influences on the fermentation process.
Therefore, our tip is: let the dough ferment until it doubles in size, this process takes between 30 and 1 hour. If you arrive in time and it has not doubled in size, do the doubling process and let it ferment for another 30min-1h, when it will probably have doubled. But if you are in a very cold place, repeat the folding process until you reach a dough that ferments until it doubles in size (up to 6 folds can be done, depending on the conditions).
FOLDING THE DOUGH:
The bread dough folding technique involves the process of gently stretching and folding the dough over itself in several stages during the proofing process, typically every 40-60min, during the exponential growth.
The folds help develop a strong gluten structure in the dough. Gluten is a network of proteins that gives bread its structure and texture. By stretching and folding the dough, you align the gluten proteins and create a stronger, more elastic network.
In addition to developing gluten, folds also help strengthen the overall structure of the dough. This is especially important in long-fermented breads, where the dough can become more delicate due to the prolonged action of the yeast.
During fermentation, yeast consumes nutrients from the dough. The folds help redistribute these nutrients throughout the dough, ensuring that all parts have access to the nutrients needed for even rising.
The carbon dioxide, during fermentation, is produced by yeast and is retained in the dough. When you make the folds, you release some of this gas, which helps prevent the dough from becoming too dense and heavy.
The folds help to ensure more uniform fermentation throughout the dough. This means that fermentation occurs more consistently, resulting in a more uniform texture and crumb in the finished bread.
Some bread recipes use the baking soda bath technique in the dough, like pretzels and bagels to obtain another texture. See more about this process in our article!
We know that there are times that call for fluffy bread and others that go with crusty bread. If you want to discover the different processes to obtain different results, visit our article: fluffy bread vs crusty bread.
Another technique used in baking is refrigerating the dough to slow down fermentation and bring more complex flavors to the dough. Visit our article if you want to know more about refrigerating sourdough.
DIFFERENT INGREDIENTS AND THEIR ROLE IN THE DOUGH:
Sugar: adds sweetness to the dough and provides a food source for yeast during the fermentation process. This can result in faster, more vigorous fermentation, producing softer bread with a golden color to the crust.
Eggs: add moisture to the dough and contribute to the bread's soft, fluffy texture. Additionally, eggs contain proteins and fats that help strengthen the structure of the dough and give the bread a richer, more delicate crumb.
Milk: adds moisture, flavor and nutrients to the dough. It also contains proteins, sugars and fats that contribute to the structure and color of the bread. Powdered milk is often used instead of liquid milk in some bread recipes.
Yogurt: contains live bacteria, but it is important to note that these bacteria are not the same type of yeast used in bread production. The yeast used in baking is usually a mixture of yeasts, such as Saccharomyces cerevisiae, which are different from the lactic acid bacteria found in yogurt. However, yogurt can be used as an ingredient in some bread recipes to add flavor, moisture, and complexity to the dough.
Butter, olive oil and lard: adds flavor, moisture and fat to the dough. This helps soften the dough and contributes to the bread's soft, rich texture. These fats can also help develop a flavorful, golden crust on bread.
Access our fermented bread catalog and learn how to make different types and recipes of bread!
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