Recipes Around

The water test is a traditional method useful for estimating the age of an egg, but it cannot definitively determine whether it is safe to eat. By immersing the egg in cold water, the egg's position is observed: the more time passes, the more the internal air chamber tends to increase, making the egg more buoyant.

This behavior allows us to distinguish a very recent egg from an older one, but it doesn't reveal the possible presence of dangerous microorganisms. To properly evaluate an egg, we must also consider the date indicated on the packaging, the storage conditions, the integrity of the shell, and the odor after opening.

How does water testing work?

The eggshell is porous. As the days pass, a small amount of water inside evaporates and is replaced by air. The air chamber located at the widest point therefore progressively increases in volume.

By gently immersing the egg in a container full of cold water, three main behaviors can be observed:

• if it remains on the bottom in a horizontal position, it is generally very fresh;
• if it remains on the bottom but tends to rise or arrange itself vertically, it is less recent;
• If it rises and floats, the air chamber has become quite large and the egg is probably old.

The test therefore measures primarily the quantity of air present, not the hygienic quality of the contents.

Does a floating egg necessarily have to be thrown away?

A floating egg isn't necessarily bad, just as an egg that sits on the bottom isn't necessarily safe. Its position in the water indicates its approximate age, but it doesn't allow for the detection of invisible contamination.

Even when an egg floats, it's still wise to check it carefully and check the date. If you decide to crack it, crack it into a separate bowl, never directly into the batter or the pan with the other ingredients.

An unpleasant, sulfurous, or markedly abnormal odor indicates that the egg should be discarded. It should not be tasted to check its condition. If in doubt, especially if it is very old or has been stored improperly, the safest course of action is not to use it.

How to check an egg after opening it

A fresh egg generally has a rounded, well-defined yolk, surrounded by a fairly firm white. Over time, the yolk tends to flatten and the white becomes more runny, spreading out more in the container.

These changes don't necessarily mean the egg is spoiled. A very runny egg white may simply indicate an older product, which can still be used in fully cooked dishes if stored properly and free of suspicious odors.

Small, whitish, filament-like growths called chalazae are normal. They help keep the yolk in place and are often more noticeable in fresh eggs.

Even a small spot of blood may occasionally appear and does not automatically indicate spoilage. It can be removed with a teaspoon, provided the egg is otherwise normal and cooked properly.

The test must be done before use

Immersing eggs in water is best only if you intend to use them immediately. The shell has a natural protective surface, and prolonged contact with water or humidity can allow contaminants to pass through the pores, especially if the shell has small imperfections.

After testing, the egg should be dried with clean paper towels and opened, without leaving it in the refrigerator for too long. It is not advisable to pre-wash all eggs and then store them.

If the shell is visibly dirty, it's best to clean it only shortly before use, avoiding prolonged immersion. Hands, utensils, and work surfaces should be washed after handling raw eggs.

Check the shell

Before using an egg, carefully inspect the shell. It must be intact, dry, and free of cracks. A broken or cracked shell does not adequately protect the contents and can facilitate the entry of microorganisms.

Any cracked eggs in the package should be discarded. It's not safe to transfer the contents to a container and store them for later use.

A naturally rough surface or slight color variations aren't necessarily a problem. The color of the shell—white or brown—depends primarily on the chicken breed and doesn't affect freshness, flavor, or nutritional value.

How to store eggs

At home, it's best to store eggs in the refrigerator, in their original packaging. The cardboard protects them from impacts, limits the absorption of odors, and allows you to easily check the date.

It's best to place them on an inside shelf, not in the door, where the temperature changes every time the refrigerator is opened. They should also be kept away from highly aromatic foods.

The pointed end can be facing downward, thus keeping the air chamber in the widest area. Once refrigerated, it's best to avoid frequent changes between cold and room temperature, as temperature fluctuations can cause condensation to form on the shell.

The date is important

The date on the packaging provides a crucial guide and should be considered in conjunction with storage conditions. The water test should not be used to ignore a much older date or uncertain storage conditions.

Older eggs, but still properly stored and unaltered, are especially suitable for fully cooked preparations, such as cakes, omelettes, flans and biscuits.

For recipes that use raw or undercooked eggs, such as some creams, sauces, tiramisu, and mayonnaise, it's best to use very fresh, pasteurized eggs. Young children, the elderly, pregnant women, and people with weakened immune systems should be especially careful with products containing raw eggs.

How to avoid contamination in the kitchen

Eggs should be cracked carefully, avoiding shell fragments falling into the container. It's best not to separate the egg white and yolk by repeatedly passing the contents between the two halves of the shell, as the outer layer could come into contact with the food.

After opening, ingredients should be cooked or refrigerated quickly. Preparations containing raw eggs should not be left at room temperature for long periods.

Utensils that have come into contact with raw contents should be washed before reusing them for already cooked foods. This simple precaution reduces the risk of cross-contamination.

In conclusion

The water test allows you to estimate the age of an egg by observing the size of the air chamber. An egg lying horizontally on the bottom is generally fresher, while one lying upright or floating is older.

However, testing does not guarantee the safety of the product. To decide whether to use an egg, you need to check the date, shelf life, integrity of the shell, and appearance and smell after opening. Always cracking it into a separate bowl and cooking it thoroughly when it's no longer fresh allows you to use it with greater caution.