Collecting, Grading & Sizing Eggs
On commercial egg farms, eggs are collected at least once a day and taken to a high-tech room called a grading floor where they are cleaned and checked for quality.
Some eggs are still gathered by hand on smaller farms but in most production facilities, automated collection belts do the job.
After an egg is laid by a hen, the egg gently rolls out of the nest box and onto a conveyor belt where it gets automatically carried out of the shed and into a separate room. Being such a fragile item, it’s very important that the eggs are treated gently as they move from one conveyor to the next.
Washing and sanitation
On the grading floor, the eggs are inspected by a series of machines to make sure only the highest quality ones make it to your dinner plate. All eggs are cleaned in Australia but different farms choose to do either dry cleaning or wet cleaning (washing).
A slightly dirty egg can be dry cleaned by using a soft bristled sanitised brush or by gently rubbing it with a sanding sponge, cloth or paper towel. Visibly dirty eggs that cannot be properly cleaned are segregated away from the clean eggs.
Some farms choose to wash all eggs in warm water and gentle sanitiser liquid as soon as they are collected. The washing process is very fast so the eggs don’t sit in water for too long and they are then dried immediately.
Many farms also run the eggs through an ultra-violet light disinfection system to kill any bacteria that may have made it onto the surface.
Modern egg grading equipment uses bright lights to inspect the internal quality of the egg. This process is called ‘candling’ as the light makes the eggshell transparent so the farmer can analyse what’s inside.
These days, many farms use automatic candling technology where machines do light spectrum analysis of the inside of the egg. If any internal defects are noticed, the eggs are removed and sent down a separate lane away from the first quality eggs.
Quality control on the grading floor also involves checking for tiny cracks that might not be visible to the human eye and measuring the height of the albumen (egg white) and shell thickness.
Automatic acoustic crack detectors contain lots of small probes that gently tap the eggs at very fast speeds as they pass through the machine. If there is a crack in the eggshell, no matter how small, the tapping energy will be absorbed, resulting in a duller sound.
Packing into cartons
After being cleaned and checked for quality, every egg is stamped with a unique code that identifies the farm where it was laid. This allows eggs to be traced back to the farm of origin if necessary.
The eggs are automatically weighed and sorted into different size cartons, such as 600, 700, or 800 gram packs.
The cartons then get stacked onto pallets and are taken to a refrigerated room where they await loading into a delivery truck.
Special refrigerated trucks back up to the cool room and create a seal so there is no temperature change between the cool room and the truck. The eggs get loaded into the truck and remain cool all the way to market.
LEARN MORE ABOUT EGG PRODUCTION IN AUSTRALIA
Learn more about these different farming systems today or take Australian Eggs' interactive tour of a commercial free range egg farm.