Before grading and packing, eggs go through several quality control processes. One of these processes is called “candling”, where a bright light is shone through the eggs to clearly identify any internal or external spots or cracks. Such eggs are removed and often used for liquid or dry egg mixtures.
Eggs are mostly produced without human handling, except for the removal of these “undergrade” eggs and in barn and free-range operations where eggs must be collected by hand.
Eggs are then sent to an egg packing unit where they are graded by size (ranging from 4 to 8) and packed.
Producing quality eggs is a top priority for farmers and there are a number of factors to consider. Read our review paper on the factors affecting egg quality in the commercial laying hen:
How to choose quality eggs
- Always check inside the carton before purchasing
- Do not purchase any eggs that are cracked or soiled (feathers or droppings on the shell)
- A rough shell with pinhead-sized lumps could be from an older hen or one that has too much calcium in its diet. These lumps could rub off and leave holes in the egg. If the shell is completely intact, the edible egg is not affected by the rough shell.
- If an egg is irregular with a flat side it means it was probably disturbed during laying. This does not affect the egg’s eating quality.
- Inside the egg, blood spots or meat spots can occur. These can easily be removed by the cook and the egg cooked as usual.
The EPF is currently in the process of producing a consumer resource on egg labelling and purchasing quality eggs.
Is one type of egg better than another?
You may have a personal preference for white or brown eggs – the quality of each is the same.
Inside an egg, the yolk colour is due to substances called “carotenoids” and is dependent on what a chicken eats, with high carotenoid content creating a darker yolk.
Recent studies have also shown there is little difference in the nutrient quality of eggs farmed in different ways. For example, a two-year study conducted at the highly-respected North Carolina State University and published in the peer-reviewed American Poultry Science Association’s journal in 2011, found the nutrient composition of free-range and cage-farmed eggs was similar. The only difference was total fat content, which was higher in free-range eggs, possibly because of insects eaten through foraging.