Dough fermentation basics

This quick guide will tell you everything you need to know about dough fermentation. This is the process that creates bread so it’s pretty handy to know what goes on.

I’ve kept this simple for now as knowing too much will bake most brains prematurely! When you’re ready to take a look at the full guide on fermentation follow the link at the bottom of the page. 

What is dough fermentation?

Basic dough fermentation is a process where the larger molecules are broken into smaller molecules through anaerobic respiration. It requires a base and a strain, in bread making the base is flour and the yeast would be the strain. 

Fermentation comes from the Latin word fermentare, meaning “to leaven”.

Fermentation is used to make many products including cheese, yoghurt, alcohol and pickled foods. They all require a base and a strain. The base is a carbohydrate whereas strains are types of fungi or bacteria.

For those that can’t remember biology from school, when we say fermentation is anaerobic it means anaerobic respiration which is an enzymic action by microorganisms where oxygen is not required.

This isn’t the only form of fermentation. Other types make food perish, matures flour and makes things mouldy.

What happens during dough fermentation?

It’s important that dough ferments. During the process, we turn a sticky mess of dough into a well supported, baked structure that is delicious to eat.

It all starts with water, flour and yeast. Once combined in the mixing bowl, fermentation quickly begins. This can be accelerated by mixing.

The longer the process continues the effects of fermentation become more active.

Here’s a diagram that shows what happens:

How dough fermentation works diagram

In this model, we see that moist flour develops into gluten. The process of yeast acting on the starches in the flour creates gas. The gas gets trapped between the strands of gluten and forms pockets of air. The air pockets expand forcing the dough rise.

The creation of lactic and acetic acids condition the dough. They do this by creating flavour, enhancing the dough handling properties and extend the keeping qualities of the bread.

The ethanol produced largely evaporates when baked though some traces remain which support odour, flavour and keeping quality.


Though not mentioned in the diagram salt does have an important part to play in making bread. Salt supports the structure of the bread, slows down the activity of the yeast and enhances the flavour. It does this by reducing the amount of oxygenation of the flour. We cover this in more detail further on in this article.

Stages of fermentation


As soon as the flour is hydrated it is broken down into sugars for the yeast to feed on. Mixing speeds up the fermentation process and strengthens the dough by adding oxygen.

Bulk fermentation

The first proof or bulk fermentation allows the dough to develop the acids required to mature the dough. Without this stage the bread will be poor in flavour and gas retaining features.

Final proofing

When the bread is at optimum maturity it is then knocked back, shaped and proofed. The knocking back forces the gluten structure to rebuild to a closer-knit community, essential for a nice soft crumb.


Dough fermentation continues until the yeast activity is halted in the oven when the temperature reaches over 60C (140F). It does this in the form of oven spring.

Is long fermentation better than short fermentation?

Fermentation quality is not just based on time. Temperature, humidity, flour quality, ratios of the ingredients all make a difference to the rate of fermentation activity.

The best way for a baker to have the best fermentation is to use good quality ingredients, including bakers flour and to manage the temperature of which the fermentation occurs. Once the best conditions are created, time is the biggest factor.

Long fermentation creates more taste and aroma, combined with better raising properties. Bread made this way is deep, interesting and extremely welcome.

The importance of good fermentation

Developing the dough to its maturity before baking at its optimum proof is essential to creating good quality bread. Quality bread will have a nice coloured, crispy crust, even crumb, and a beautiful smell and flavour.

More about dough fermentation

Dough fermentation is a big subject, and so I have written a more comprehensive article for experienced bread bakers. To find out about the process of fermentation in more detail, view the full guide on the dough fermentation process,

Return to the how to make bread course homepage.

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