Egg Freshness Test in Water (Egg Float Test)
The Egg freshness Test in Water is used to test whether your eggs are good or bad to use. Some people say “do bad eggs float”. In this post we will answer this question.
So say you have bought some eggs from a local store that have just passed their best before/expiration date and you want to find out whether they are still good to use. Even if the expiration date on the carton has not been reached eggs can still go bad due to various factors including how they were stored after being laid.
So you might be asking yourself how do I check whether my eggs are fresh. A well established and reliable method used by all manner of cooks is the float test.
So what equipment do you need to have to complete the float test? Quite simply a glass and some water, that’s all. No fancy equipment needed at all.
- Fill the large glass with water to the top.
- Then get you eggs one by one and place them in the glass full of water.
- What you will soon notice is that some eggs will rest at the bottom of the glass in a horizontal position, some will rest towards the bottom in a more vertical position and finally some may float towards the top of the glass of water in a more vertical position.
Grouping Good and Bad Eggs
As you complete the test start to group the eggs into those that float, those that sink and are slightly vertical and those that sink and lie horizontally on the bottom of the glass during the float test.
The eggs that sink and settle at the bottom of the glass in a horizontal position are the freshest eggs whilst those that float to the top of the glass are bad. The group of eggs that sinks to the bottom of the glass but lie in a more vertical position are still good to eat but are less fresher and need to be eaten as soon as possible.
So the answer to the question “do good eggs float or sink” is that the freshest of eggs will sink to the bottom.
Science behind the Float Test
You might be asking yourself why some eggs float in water and others sink. Here’s the science behind the egg freshness test in water. It’s all down to air pockets being present in the egg. When a bird lays an egg at its freshest point the egg will have in most cases a very small air pocket or none at all. This means that the fresher an egg the more likely it is to sink as there is not enough air on the egg to keep it afloat.
As the egg begins to age both moisture and gases within the egg will seep through the egg’s porous shell. So as it ages more of this moisture will leave, which in turn provides more space for air to enter the egg. This process ensures that the air pocket grows and grows. So in bad eggs this air pocket will be large enough to allow the eggs to float in water.
Good Eggs Sink
Bad Eggs Float
So when you’re ready to cook or boil your eggs whether you use an electric egg cooker or a pan of boiling water use the float test to ensure you only use the freshest eggs.
Related: Tips on Cleaning Egg Cookers