All of the eggs have an airbag in their wings. The skin of the egg also has tiny openings that exchange gases from the inside to the outside or vice versa. Gradually during egg storage, the volume of the airbag increases due to the accumulation of some gases, and these changes are the basis of a simple method for detecting egg freshness.
When fresh eggs are dropped into the water, the egg is placed horizontally on the bottom of the container because the volume of the bag is very small. As time goes on, the volume of the pouch increases and the egg's head gets closer to the surface of the water because it is lighter so that the egg will be completely vertical in the container full of water after 20 days of storage. This way you can roughly guess the shelf life of the eggs.
When cooking, never lay eggs directly into ingredients such as cakes or any other food. First, break the eggs into a separate container and check out a few things: First, the eggs have an unpleasant odor that results from the release of sulfur compounds and gradually increases during storage.
Second, by examining the white and yolk appearance, you can get a good estimate of the freshness of the eggs and avoid using old eggs. The yolk in the fresh egg after breaking is completely prominent and is centered in white and separated by a thin layer of protein called vitellin. The whites in the fresh egg consist of two parts, a thick section around the yolk and a thinner section around the thick white.
As the egg retains days, the vitellin layer loses its shape, resulting in the yolk becoming wider in the fractured egg and no longer convex and evenly distributed throughout the last days of storage after breaking.
On the other hand, the thick white is thinned and watery due to changes in the structure of its proteins, and is completely dispersed in the container after breaking. As pathogenic bacteria gradually enter the egg through the stomachs, it is best not to consume eggs with severe signs of aging.
