Can you eat eggs with black spots on the shell?

Eggs are a type of egg we often eat. When eating eggs, we must pay attention to whether the eggs are fresh. If the eggs are not very fresh, the nutritional benefits to the body will decrease, and even problems that affect your health will occur. For example, when there are black spots on the eggshell, it means that the eggs have been infected with bacteria, especially Salmonella infection is more serious. At this time, such eggs can no longer be eaten.

How to distinguish the quality of eggs

1. Knock it open directly

Crack the eggshell directly. If the yolk is scattered, the egg white and egg white are mixed together, or there is a rancid smell, it means the egg has gone bad.

If the yolk is nearly spherical and slightly convex, and the albumen (or white) is just clumped around it, the egg is fresh. If the yolk is a little deflated and the white is clear but still clumping together, the egg may be a little stale, but it's still edible. If the yolk is flat and the egg white is runny (almost watery), the egg is bad. This is the most direct way to judge.

2. Floating test

Place the eggs in a basin of cold water with the water level about twice the height of the eggs. If the egg lies flat on the bottom of the water, it means it is very fresh. Fresh eggs will sink to the bottom of the bowl and may be against the bottom of the bowl on their side. But if they are tilted or standing upright in the water, it means they have been stored for a long time. Slightly stale eggs (about a week old) will also sink to the bottom of the bowl, but they will float slightly up and down. If the eggs float on the water, it means the eggs have gone bad and you should not eat them.

Principle: The longer the eggs are left, the more water and carbon dioxide the substances in the eggs lose, and the larger the air chamber in the eggshell becomes. When the air chamber becomes larger, the egg will float more easily on the water, and it will also make a shaking sound when shaken.

3. Shake and listen

Put the egg between two fingers and shake it near your ear. A fresh egg will not make any sound. Rotten eggs make a crumbly sound, while those with large holes make a hollow sound. Cracked eggs have a snapping sound. The eggs that make water sounds are those that have been left for too long.

Tips: Many people will subconsciously shake the eggs when buying them to determine whether they are loose yolk eggs. This is a common method. However, this method is not very reliable, because even the freshest eggs will make noises if shaken too hard. It is recommended to combine with other identification methods for safety reasons.

4. Daylight observation

Hold the egg in both hands like a cylinder, and look through it against the sunlight or light. If the egg is slightly red and translucent, with a clear yolk outline, it is fresh; if it looks dark and opaque and has stains, it means the egg has deteriorated.

5. Touch

Touch the egg with your hand. The rougher the eggshell, the fresher the egg; the smoother the surface, the less fresh it is. In addition, eggshells that have been exposed to rain or moisture have gray and black spots. There are oily stains on the shell of rotten eggs.

6. Nose smell

Blow a breath of hot air onto the eggshell with your mouth, and then smell it with your nose. Good eggs have a slight light lime flavor.

7. Turn the eggs

Place the egg on a flat surface and gently turn it with your fingers. When a fresh egg turns, there is resistance in the eggshell and it will stop after two or three turns. A bad egg will take a long time and be faster to turn. If the egg turns neither fast nor slow, it is no longer fresh.