Ungraded cases of eggs are loaded onto an automated loading system that breaks down the cases into layers. The eggs are picked up by vacuum powered suction cups and loaded onto rollers which take them through the grading process.
Eggs are graded by quality. The ones you buy at the grocery store are Grade A (cleanest, with no stains or cracks, the smoothest surface and most uniform shape).
The eggs are rinsed with a high-pressure chlorine based sanitizer that maintains a PH of 11 and wash water temperature of 115˚C. They then go through a series of brushes that scrub the shells clean. Next, they are rinsed with fresh, warm water and finally warm air is blown on the eggs to dry them off.
Following the washing process, eggs are taken though a series of cameras which inspect the exterior shells for any eggs that may not have come clean during the washing process. They then pass over a series of sensors that measure the strength of the egg shell and can tell if there is any crack in the shell. The eggs with cracks or stains on the shell are identified and separated from the clean ones.
All eggs roll over one of the scales that weigh each egg to the nearest 10th of a gram. The weight allows us to determine the egg size based on Canadian Egg Regulation Sizing Standards. The following table outlines the minimum weights for each size:
CANADA GRADE A EGG SIZE
EXTRA LARGE SIZE
Below 42 Grams
Each egg undergoes an automatic candling process which involves flashing an intense light through the egg shell. A sensor receives the light on the other side and is able to filter out any imperfections such as blood spots. Any eggs with these imperfections are removed and used for other purposes, such as processing.
Each egg is allocated to one of 20 packers, based on size, brand and packaging.
There’s a wide array of packaging for eggs, including pulp (generally from recycled newsprint), Styrofoam or plastic. The type of packaging selected depends on factors such as cost, availability and the type of product.
Styrofoam is a good source packaging material for its ability to withstand humid climates and machinability. There is less waste with this material and less carbon is used in the transport of these cartons to egg packing stations because of its lightweight properties. To many people’s surprise, Styrofoam is actually recyclable with companies that find post consumer uses for the material. Plastic is often used to showcase specialty eggs. It is the most expensive type of packaging but is now available in recycled PET material.
Each carton is stamped with a best before date of 45 days after the day on which the eggs were graded. The graded eggs are then stored in another cooler where the temperature is kept below 10˚C.