A user asked the following question:
Is it normal that during the process of cooking at low temperature more and more air progressively appears in a bag that contains food that was previously vacuum packed?
Here is the chef’s answer:
The effect you mention happens because the vacuum process was not carried out correctly. As you know, some products contain air inside the food structure. If insufficient time is left for it to release during the vacuum process, what happens is that it will release during cooking. Therefore, the air is released from the inside. This is because its structure changes and during cooking, the ingredient is squeezed in such a way that it releases the air inside it. This phenomenon is common, for example, in artichokes, meat that is heavy and thick or contains other elements. To avoid this, use the “vacuum plus” process (possible with Sammic machines). You could also place the product in the vacuum machine on a tray and run the vacuum process a couple of times before putting the product in the bag.