Egg Float Test: Do Good Eggs Float or Sink?

Egg Float Test: Do Good Eggs Float or Sink?

Do good eggs float or sink?

Straight to the answer; good eggs don’t float! They sink! eggs that float should not be consumed because they are harm to your body system.

So when you conduct an egg float test and you have floating eggs; don’t think twice before discarding them.

A curious mind would then ask; why does an egg float?

The answer is simple and straight forward; good eggs are made up of three main parts; the shell, the white albumen and the yolk. The reason why bad eggs float is because the albumen and the yolk are all gone (at least a larger percentage of it) and it is then replaced by air.

When eggs float in water; it means the weight of the egg is smaller compared to that of water. Scientifically; it means the water is denser than the egg. Which in a normal circumstance it’s supposed to be the other way round.

Testing Eggs For Freshness.

The egg float test is a good way of testing egg freshness as well. Take note that if an egg fail the freshness test; it does not mean they are not good for consumption; it’s just an indication that they have been out there for a while, and as a result should be consumed as soon as possible.

How to test for eggs freshness:

Follow the simple steps below to conduct a simple egg freshness test:

  1. Get a big bowl. Big enough to accommodate two (2) eggs. Although we would be testing an egg at a time.
  2. Fill the bowl with cold clean water; about half way full. (Make sure the water is NOT salty)
  3. Gently place your egg in the bowl filled with water.
  4. Eggs that lay on it’s side at the bottom of the bowl are quite fresh.  they can still be stored in the refrigerator for future use.
  5. Eggs that stand upright in the bottom of the bowl are the ones that flunk the freshness test.
  6. Floating eggs are bad eggs and should be disposed right away. 


It should be noted that eggs that stand upright in the bottom of the bowl egg float testare still good for consumption, because they are good eggs, albeit they have been on the shelf for a while and as a result they should be consumed as soon as possible, because future storage may turn them into bad egg (floating egg) which should not be consumed.

The Science behind egg freshness test:

Although egg shell usually looks hard, it should be noted that they are actually porous and the pores on the shell allows passage of air in and outside the shell.

When an egg is placed on the shell longer than enough, the liquid content inside the egg (albumen and yolk) would gradually escape through the pores on the egg shell, and the space inside the shell would be filled up with ordinary air.

Since the density of water is greater than that of air (which is what you have in a bad egg), the egg shell filled with air would eventually float in the bowl filled with water.

Lesson: Water has a higher density than Air.

Egg Float Test In Water

Egg test in water is done for two major reasons:

  1. To determine if the egg is still good for consumption.
  2. To determine the freshness of the egg.

It should be noted that eggs that fail the freshness test are not bad egg, they are still good for consumption but they should be consumed as soon as possible before they get become bad egg.

NB: Fresh egg are best served for the young ones and aged people.

How to test eggs in water:

The steps involved in conducting the eggs in water test for both freshness and good eggs are pretty much similar. The only difference is how the result is interpreted.

To test for egg freshness; refer to the guide above. To test if an egg is a good or bad egg; then use the method to interpret your result after following the same steps as the freshness test.

Eggs that float in water are BAD eggs, while the ones that sink are good eggs.

Egg in salt water.

The science behind the two egg test relies solely on the weight difference. As explained earlier, good eggs are supposed to be denser (more weight) than water, at any given time. As a result of this; good eggs would NEVER float in ordinary, clean, clear water.

But there is an exception to this rule. What if there is a way of making the water heavier (denser) than the good egg? Will good egg still pass the floating testing in heavier (denser) water? They answer is NO.

Salt are known to make water more dense. To prove this theory; get a bowl filled with water and dissolve a handful amount of table salt in the water. You can label the salt water (Experiment A).

Get another bowl filled with clean, clear water and label it (Experiment B).

Now, get a newly bought egg, with valid usage date and drop the egg gently inside the Experiment B bowl, you would notice that the egg would sink to the bottom of the bowl.

Pick up the same egg, dry it with your kitchen towel and drop it gently into the bowl labeled Experiment A. You would notice that the same egg would float in Experiment A, despite the fact that the egg is still a good egg.

This is a complete test of material density, and it’s application can come handy when testing for good and bad egg

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