Autolyse (Auto-Leese) is a term used in baking that refers to a simple method which improves the flavor and quality of bread. Essentially, the flour and water in the formula are mixed together and left to rest. The dough might be resting but the microorganisms are going to work.
The resting period can vary from 20 minutes to several hours or even overnight. After the flour and water are mixed, the gluten bonds begin to form and the many enzymes begin to digest starch and protein, especially the Amylase and Protease enzymes. This enzyme action is a kind of self-digestion or an action where the enzymes work to break down the grain cells that produce the enzymes. This process was discovered and made popular by Professor Raymond Calvel, a baker and chemist who lived in France. He is considered to be the person who started the Artisan Bread revolution.
During this time of rest, the protease works on the gluten as it bonds to modify it and the amylase digests the starches into sugars. Salt inhibits the microorganisms, so the salt is not added until the autolyse period is over. Once the salt is added, it inhibits over-fermentation and moderates the activity of the microorganisms. Salt also tightens the gluten and makes it stronger. During autolyse, acids are produced by fermentation which also has the effect of strengthening the dough.
While the microorganisms have the chance to work uninhibited though, they modify the dough’s structure and flavor. The improved flavor and texture in the resulting bread is enough for the method to have spread around the bread baking world and it is now universally used as a standard method of improving the quality of bread.
A true autolyse is when only the flour and water are mixed together without any other ingredients. This is not always possible when using a high hydration pre-ferment as an addition to the dough. After the autolyse period, the rest of the dough ingredients are added to the final dough and bulk fermentation commences.
A modified autolyse is when the yeast/sourdough or pre-ferment is added to the flour and water, but the salt is still held back until after autolyse. I use this method often.
Autolyse is not always necessary or needed. You can mix straight dough where all of the ingredients are added at once and the bulk fermentation starts right away without an autolyse period.
Autolyse is just another tool bakers use to modify the outcome of bread. It is a very useful tool and very simple to use, it just takes a bit of extra time. When you think about it, every time you feed your starter and allow it to ferment, it is an autolyse. Pre-ferments are already autolysed as well. So in formulas that call for pre-ferments or a combination of pre-ferments and sourdough starter, I will usually leave out the autolyse period.
I will also leave out the autolyse when the inoculation percentage of the starter in the dough is very high for the same reason as stated above; a very active starter is actually already autolysed.
Here are some experiments I did long ago on autolyse: