Store eggs fat end up

Store eggs in a carton

How do you store your eggs? Which end of the egg do you have facing upwards? This is a question that is raised surprisingly often.

And the answer is simple. Store eggs with the fat end facing upwards.

We have been doing this for a while, but never knew the reasons why it’s best to store eggs fat side up. There are two basic theories to explain the reason behind storing eggs fat end up.


1) The air cell in an egg will be found at the large end of the egg, so less moisture will subsequently evaporate out of the egg if it is placed fat end up. More information on this theory can be found here.

I’m not sure about this first theory. My understanding is that the air cell in the egg will move about the egg depending on its rotation, and having the egg fat side up isn’t likely to have that big a difference in quality if it’s only a marginal difference in moisture.

2) The egg does not completely fill the interior of the shell – there’s a pocket of air between the egg and the shell. This air pocket allows for the production and reproduction of bacteria. In order to minimise the chances of bacteria infecting the egg, the air pocket should be kept away from the egg yolk (which is more susceptible to bacterial infection). Storing the egg fat side up, means that the air pocket stays away from the yolk and reduces the likelihood of bacteria causing problems upon consumption. More information on this theory can be found here.

I like this theory more, because it seems more common sense. I know eggs that are stored fat end up stay fresher for longer, and the reduced presence of bacteria goes some way to explaining that.

Egg carton store eggs
It’s easy to store eggs with the fat side up. It might take some getting used to – but fresher eggs are always better!

Rach is planning on setting up her own experiment to categorically determine what are the best methods of storing eggs (including temperature, sunlight, rotations and humidity) provided it’s all possible. Once she has completed her scientific experiments the results will be shared to settle this once and for all!

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