Like any other product, eggs must be fresh. But sometimes we do not know how long they have been in our refrigerator, and even more so we can’t guess how long they were on the counter in the store before we bought them, and the conditions for their storage are also little known to us. And this is also an important criterion affecting the quality of the product.
   So, to dispel all doubts about the freshness of eggs, there are several ways to find out.

Method one: before you buy.

Before you buy eggs, you should pay attention to their appearance.
  Those who have recently demolished the chicken have a matte surface, and those that have already lain down for some time become glossy.

After an external inspection of the goods, try to shake the egg. If the inside is “loose”, then the egg is stale. Since the egg tends to dry out during storage, the inner shell is separated from the shell and the contents are separated.

Method two: check eggs for freshness at home.

To do this, lower it into a concentrated solution of kitchen salt. If the egg lies at the bottom of the dish, then its age is not more than a week. If the blunt end rises upward but is sharp at the bottom, then the egg is about 10 days. If it floats in solution, the egg is already stored for about 2 weeks. And if swimming, half leaning out of the water, it is better not to eat it.

Method three: the definition of freshness in the cooking process.

Of course, in this situation, it is not the case when the egg emits a fetid odor. This is all clear.

How fresh the egg will be following signs:

• If a broken egg spreads to the pan, the egg is no longer fresh enough, it is suitable for use, but you should not keep it. In fresh, the protein is denser and more viscous.
• The same with the yolk. If a broken egg yolk immediately spreads - its freshness is questionable.
• Have boiled fresh eggs  the shell is cleaned much worse than the one that has not lain for more than one week.

Egg is an important food product that is extremely diverse from a culinary point of view, since besides egg dishes themselves, egg components (yolk and protein) are used in the preparation of many other dishes: for example, egg yolk is stuffed with soups and sauces, and whipped proteins are often necessary for stabilization. For example, soufflé. The nutritionally-biological properties of eggs are mainly due to biologically valuable proteins - one egg covers 15% of a person’s daily protein requirements. In terms of nutrient content, protein and yolk are significantly different from each other: the first consists mainly of water and about 11% protein, and the yolk is rich in protein-phosphorus compounds, fat, minerals and vitamins. Along with fat-soluble vitamins A, D and E, it contains calcium, phosphorus and iron. Protein contains water-soluble vitamins, sodium, potassium and chlorine. Nutrients of eggs can be absorbed by a person almost completely, namely up to 95%. And, nevertheless, you should not eat too many eggs (more than 3 pieces a day) because of the high content of cholesterol in the yolk.

A decisive influence on the quality of eggs has proper storage. Eggs react sensitively to the environment, as odors and bacteria can penetrate through their porous shells. They should always be stored at a cool temperature (8 to 10 C) and at high humidity. Best of all - in a special compartment of the refrigerator, away from strongly smelling products. In such conditions, eggs in the shell are stored for 3-4 weeks. Broken eggs  stored for 2 days, the yolk, covered with water, also 2 days, and protein - up to 14 days. Frozen egg mass, no matter in what composition, is stored for about 4 months.

How to determine the egg freshness?  In appearance, it is almost impossible to determine whether a fresh egg or not. But there is simple ways to check:.

- If you shake a fresh eggthen it will not make any sounds
  - There is such a rule - the older the egg, the more moisture evaporated from it  through the porous shell. Due to this, the air chamber increases and the egg becomes lighter.
- Buoyancy test. If an egg in a glass with a 10% solution of salt (10 g of salt per 100 ml of water) sinks to the bottom, then it is fresher. At about a 7-day egg, the air chamber is longer. Egg rises with a blunt end up. If an egg floats completely on the surface, then its air chamber is even larger; it may already be several months.
- Test by breaking eggs. In a very fresh egg, the yolk is strong, well convex, has a beautiful round shape and is surrounded by two rings of protein: the inner compact and the outer, thinner.
- Cooking eggs.  The easiest way to cook eggs is to cook in the shell. It may be advisable to lightly puncture the blunt end of the egg with a thin needle to remove air. Then the shell will not crack during cooking. If you need to boil several eggs hard-boiled, it is better to put them in boiling water in a sieve. Cooking time starts from the moment when the water boils again. But this can only serve as an approximate value, since the cooking time depends on the place - the higher the sea level, the longer the process of cooking eggs takes, as well as the temperature of the eggs before they are put into boiling water. Although they do not need to be cooked for too long, otherwise the protein will release hydrogen sulfide, and then the eggs will smell unpleasant. After cooking, it is recommended to rinse the eggs well with cold water to make them easier to clean.

Cooking time:
4-5 minutes: the protein is solid only from the outside, the yolk is still liquid and dark yellow in color.
5-6 minutes: the protein is solid, the yolk inside is still liquid, the outer edge has already slightly cured.
6-8 minutes: the whole protein is hard, the yolk is slightly soft in the middle, the rest of the soft.
7-9 minutes: white and yolk solid; the yolk in the middle is slightly creamy, its color becomes lighter.
10-12 minutes: white and yolk can be cut, the yolk is already pale in color. 15 minutes: The yolk loses its color even more, becomes dry and crumbles when cut.

Enjoy your meal!

You cannot look inside the egg, and nobody wants to run into the rotten one, especially in those cases when they take a large batch for future use. But people have long invented many ways to check the freshness of eggs without breaking the shell. Our grandmothers knew how to do this, which means we will learn.

Visual inspection

By weight

It is necessary to take the egg in your hand, feel its weight and think about whether it is too light. A fresh egg is filled with protein completely, so its weight is palpable. The longer the egg is stored, the stronger it dries. As a result of the loss of moisture, the weight of the contents decreases, the air chamber (at the blunt end, this so-called “pug”) increases, the egg becomes lighter and lighter.

By sound

By taking an egg in your hand, you will surely involuntarily shake it. And do it right! This method is also very good when you think about how to determine the freshness of eggs. A good egg will not have any sound or hesitation inside. If, while shaking, the contents clearly dangle and beat against the walls, throw out such an egg without hesitation, it is definitely rotten!

By type of shell

If an egg has been demolished recently, literally a day or two ago, its shell is dull. If it is torn down many days ago, the shell will be shiny. If the egg looks too clean, as if “washed”, it will not be stored for a long time, because during the “water procedures” it lost its protective film. Such eggs preserve freshness for no more than 10-12 days, and “unwashed” ones can be stored in the refrigerator for at least a month.

To the skylight

There is a special device - "ovoskop", where the eggs shine through a directional beam. At home, you can simply hold the egg to a bright lamp and see if there are dark spots inside.

Buoyancy check

The most reliable egg test for freshness is the salt water immersion test. If the egg has sunk, it is definitely fresh. The longer the egg is stored, the more it dries and becomes easier. So if it floats in a salt solution, does not sink, but does not float up, it means that it is, of course, not the first freshness, but it is quite suitable for food. If the egg happily comes to the surface, this is a sure sign of its absolute unsuitability for eating.

Salts for this experience usually take an incomplete tablespoon, calculated for half a liter of water, but the concentration of the solution is not so important here, because the spoiled egg will float even in clean water.