After eggs are laid, gathered and washed, they get graded and sized before they’re packed into cartons. The grade is decided by checking both the outside and the inside of the egg. On the outside, the checker looks to see if the shell is clean and unbroken and has a normal shape and texture – without bumps, ridges, thin spots or rough areas. The shell color doesn’t matter. On the inside, the checker looks to see if the white is firm, thick and clear. The checker also looks to see if the yolk is the right size and shape and has no blemishes. Through the shell, the checker can see the size of the air cell, too. The smaller the air cell, the higher the grade. Eggs are graded AA, A and B. AA is the highest just like an A is the highest school grade.
In the past, a candle was held up behind an egg so the checker could see inside the egg without breaking it. Today, eggs move on rollers over a strong light instead of a candle. But grading is still called candling. Another way to check the quality of an egg is to break it out onto a plate. When the egg is broken out of its shell, the checker can see the white and yolk even better. Candling is used most of the time because most eggs are sold in the shell. But, some eggs are randomly broken out as an extra quality test. Here’s what different grade eggs look like when broken out:
Grade AA
The insides of the egg cover a small area. The white is firm. There is a lot of thick white around the yolk and a small amount of thin white. The yolk is round and stands up tall.
Grade A
The insides of the egg cover a medium area. The white is pretty firm. There is a good amount of thick white and a medium amount of thin white. The yolk is round and stands up tall.
Grade B
The insides of the egg cover a very wide area. The white is weak and watery. There is no thick white and the large amount of thin white is spread out in a thin layer. The yolk is large and flat.
Now that you know what the grades look like, which egg grade/s do you think would be better for frying or poaching? Which for hard-cooking? Which for making scrambled eggs, omelets and quiches and for baking?
GETTING GOOD GRADES
Grade AA is best for frying and poaching, but A is okay, too. Because the whites are more firm, grade AA or A eggs will have better shapes when you break them out. They won’t spread out as much in the pan when you fry them. There won’t be as much white that breaks off from the egg and forms “angel wings” in the water when you poach them. Grade B eggs would spread out a lot if they were fried and a lot of the white would float off into the water if they were poached.
Grade A is better for hard-cooking. Because the smallest air cells are in grade AA eggs, the membranes just inside the shells are very tight up against the shells. This makes it harder to peel off the shells without taking some of the whites along with the shells. Because the thinnest whites are in grade B eggs, the yolks sometimes move around inside the eggs. This can cause the yolks to be off center. Off-center yolks can make pretty funny looking hard-cooked egg slices or deviled eggs. Grade A shells will usually be easier to peel than grade AA and grade A yolks are more likely to be centered than grade B.
Any grade can be used for scrambled eggs, omelets, quiches and baked goods or any other recipe in which the shape of the egg isn’t important. Once you beat them up, all the different grades of eggs will work the same in a recipe. It doesn’t matter if their whites are thick or thin or their yolks are tall or flat. Grade B eggs don’t look as pretty as grade AA or A, but they have the same good nutrition. You won’t usually find grade B eggs in the stores. Some are used by bakeries or restaurants, but most are made into egg products.
No matter what grade, eggs need to be kept in the refrigerator whenever you’re not cooking or eating them. Refrigerating eggs keeps their quality high for a longer time. If you leave eggs out at room temperature, their quality will go down faster. When the quality goes down, the eggs’ air cells grow, their whites thin and their yolks flatten. Scientists say that a day at room temperature will cause an egg’s quality to go down as much as a whole week in the refrigerator.