Punching down the dough sounds quite aggressive and should not be taken literally. Punching down, or knocking back the dough really just means gently degassing it.
Yeast produces carbon dioxide during the fermentation process. It is sufficient to gently squeeze some of the gas out of the dough with your fingertips, then stretch it a little and fold it. Degassing the dough is an important step in making yeast dough, whether you’re baking pizza or bread.
You should degas the dough one to three times, depending on the type of dough you are working with and how long the first rise (bulk fermentation) lasts. It may be enough to deflate the dough once, if the first rise is short. However, if the first fermentation takes longer, degassing can be repeated up to three times. Good recipes usually provide guidance on this.
If the bulk fermentation takes place in a fairly warm environment, you can make the first folding approximately 30 minutes after mixing the dough.
You have to be very careful with the dough when dividing and shaping it so that the gases remain inside. During proofing, which is the final rising phase before baking, the dough must be handled carefully. While on the subject of proofing, you may be interested in my article on what happens if you bake the dough before it’s fully risen.
Why is it necessary to degas the dough?
There are several reasons why leavened dough needs to be degassed. However, you should not squeeze all the gas out of the dough, so press and fold it gently.
The carbon dioxide accumulated in the dough stretches the gluten and can overstretch it if it’s left to rise for too long. This leads to over-proofing and collapsing. Folding the dough helps the gluten network to reorganize, thus making its structure stronger.
As a result of folding the dough, the yeast cells and sugars are rearranged, so that the yeast gets fresh nutrients and can continue fermentation. Too much carbon dioxide prevents the yeast from feeding and can kill it.
The temperature difference between the outer and inner surface of the dough is evened out by gentle stretching and folding.
How can you determine when to knock back the dough?
The volume of dough made from white wheat flour should double, but those made from whole wheat flour or rye flour won’t rise as much. However, just by observing the difference in size, you may not be able to precisely determine when the dough has risen sufficiently.
You can determine more precisely whether the dough has risen enough by gently pressing it with your finger. If it remains indented, the dough has relaxed and risen well. If, on the other hand, it is still elastic and springs back, it must be left to rest further. This takes about 30 minutes in a warm kitchen environment.
How should you properly punch down the dough?
The term “punching down” is used for degassing the dough because many people use their knuckles.
However, this is an old way of handling dough, the modern and better technique is gently pressing, stretching, and folding. The goal is not to completely squeeze out the gases contained in the dough.
- Transfer the dough from the proofing bowl to a lightly floured surface and lightly press it with your fingers.
- Gently pull the sides and fold them towards the middle, from the right and left, then roll up lengthwise.
- Put the dough back in the bowl so that the seam is at the bottom and the smooth surface is at the top.
Doughs made with sourdough starters need to be handled more gently than yeast doughs. These doughs should not be strongly deflated, because afterward, they may not have the capacity to rise again.
Bread made from the more degassed dough will have a more uniform crumb structure, which is good for sandwich bread, for example. The dough for more rustic bread, such as ciabatta, must be handled carefully to squeeze out as little gas as possible.
Punching down the dough simply means degassing it. The purpose of degassing the dough is to gently squeeze out some of the carbon dioxide produced by the yeast. This should be done one to three times, but only during the bulk fermentation phase.
Stretching and folding the dough strengthens the gluten structure, and the yeast gets fresh nutrients and continues the fermentation. Once the dough has been divided and shaped, it must be handled carefully so that the gases remain inside. While on the subject of gases in the leavened dough, you may wish to read my article on does dough oxygen to ferment.