What kind of fresh eggs

To determine whether an egg is fresh, methods such as observing the shell, shaking and listening to sound, light penetration testing, water float testing, and odor identification can be used. Fresh eggs have rough and crack free eggshells, no sound when shaken, even light transmission, sink to the bottom of the water without any odor.

1. Eggshell Observation

The surface of fresh egg shells is rough and covered with white frost like powder, with a solid and smooth texture. Due to prolonged storage, the pores on the surface of aged eggs gradually expand, making them smooth and even slightly cracked. If there are obvious cracks or mold spots on the eggshell, it may have deteriorated. During inspection, gently wipe the eggshell. Fresh eggs may leave a slight powder, while aged eggs may have less or no powder at all.

2. Shake and Listen

Gently shake the egg close to your ear. Fresh eggs have thick egg whites and small air chambers, so you can hardly hear any sound. If there is a noticeable sound of water or impact inside, it indicates that the egg white has become diluted or the air chamber has expanded, resulting in a decrease in freshness. However, it should be noted that excessive shaking can cause the yolk membrane to rupture, affecting the accuracy of judgment.

3. Light transmittance test

Use a flashlight to illuminate the egg in a dark place. Fresh eggs should have uniform light transmittance, blurred yolk contours, and be located in the center. The diameter of the air chamber should not exceed 5 millimeters. If the yolk is found to adhere to the wall, the air chamber is enlarged, or there are dark spots, the freshness is low. This method can detect abnormal conditions such as bleeding silk eggs and scattered yellow eggs.

4. Water Float Test

Place the egg in clean water, and the fresh egg will completely sink to the bottom and lie horizontally due to its high density. The egg chamber that has been stored for a long time will expand, and one end will curl up at a 45 degree angle. If it floats completely on the water surface, it may have deteriorated. During testing, the water temperature should be close to room temperature to avoid cold water causing eggshell shrinkage and affecting the results.

5. Odor Identification

Fresh eggs have no obvious odor after opening, the egg white is gelatinous and layered, and the yolk is full and raised. Rotten eggs will emit a putrid odor of hydrogen sulfide, with thin and cloudy egg whites and flattened egg yolks that are easy to disperse. If the taste becomes sticky or bitter after cooking, it should be stopped immediately. When storing eggs, they should be kept dry and ventilated, with a temperature of around 4 ℃, and avoid coexisting with strongly scented foods. When purchasing, priority should be given to boxed eggs with a recent production date, and loose eggs should be inspected one by one. Freezing eggs can extend their shelf life, but it should not exceed one month. It is recommended to conduct a freshness test again before cooking to ensure food safety. For special populations such as pregnant women and infants, it is recommended to use sterilized eggs or organic eggs within their shelf life.