How do you know if a chicken egg is still good to eat?

The chicken coop is a permaculture staple, with chickens pecking in the orchard doing a good job of aerating the soil and enriching it. But as a gardener or hobby chicken farmer, you still have some things to learn. For example, you've found eggs in the coop, but you're not sure how fresh they are. What should you do?

Just like when you buy eggs at the store, the date printed on the package is not really a "best before" date. In fact, most store-bought eggs stored in the refrigerator stay fresh for weeks after the printed date. So don't worry, because eggs keep well in the air.

However, since eating a spoiled egg can cause food poisoning, it's best to be careful when eating eggs where you have doubts about the freshness. Before you throw the eggs in the trash (or rather to your chickens, as they are also fond of them), here are four quick and easy ways to tell if an egg is expired.

1. The Swim Test

A fun and effective test to determine the freshness of an egg is to see if it sinks when you dip it in water. To do the egg-in-water test, simply fill a glass or bowl with cold water and submerge the eggs. If the eggs sink to the bottom and lie flat on their sides, they are still fresh, but if they sink but stand on one end at the bottom of the glass or bowl, they are not as fresh but still edible. Of course, if any eggs float to the surface, they should not be eaten.

Is this method scientific? Absolutely, you should know that eggshells are semi-permeable, which means that air can pass through them. So the longer the egg has been laid, the more air can penetrate through the shell, making it float.

2. The egg noise test

Another method that is less reliable than the swim test is to hold an egg up to your ear and shake it. If you can hear liquid rattling around inside, it's gone bad. On the other hand, the absence of noise is a good sign. In fact, a splashing sound usually indicates an old, watery yolk.

3. The smell test

If the egg does not pass the smell test, it is best to throw it away. When broken, the egg should have a neutral odor, not a special odor such as sulfur, gas or acid.

4. The color test

Just before you make that cheese omelet with your chickens' eggs, take the time to observe the yolk and egg white once they've been broken on a flat surface. Fresh eggs have a bright yellow or orange yolk, while the egg white is slightly stiff and stands around the yolk. The white of a less fresh egg will be flatter and more spread out. If your eggs are about to expire, a delicious way to use them is to boil them, for example.

• Want to know more about chicken? Read our article on chicken red lice and how to get rid of them.