An AA egg should have a yolk outline that is only slightly defined and that pretty much blends into the surrounding white. In order for the yolk to have become stuck to the shell to the degree that it cannot be dislodged without breaking the membrane, it had to have been stored for a long period of time in a fixed position. You may be able to remove the spot with the tip of a spoon. No matter what grade, eggs need to be kept in the refrigerator whenever you’re not cooking or eating them. Let’s get into how eggs are graded according to their external & internal qualities: External egg quality is determined by its shell, texture, color, shape, and soundness. For frying or boiling, AA or A should be fine for most, unless you are a really obsessive foodie. Look for the Canada Grade-A symbol on the packaging of eggs you buy, to ensure top quality! B grades will be watery and thin. These changes only become apparent in the lowest quality B grade eggs. Egg white – The egg white is composed of four structures. So, while candling it moves slightly away from the center and yolk outline is only slightly defined. So the different shapes are variations on “rounded with large end and smaller end.” There is considerable variation allowed. Begin the egg grading process by checking the quality of the shell. However, the white of a fresh egg is thick and the yolk is not watery, so the yolk will not mix with the egg white very freely. The eggshell should be clean, unbroken, and smooth. Eggs that receive a grading of “A” are required to have a smooth clean shell that is free from any dirt, mud, feathers or hairline cracks. For the most part, you simply want to avoid B grade eggs for this use, but when poaching, which is difficult to master, go for the freshest egg possible. It is the distance from top to its bottom when the egg is held with the air cell up. They are mostly used for bakery and other commercial operations. The cook does not need to be concerned with high, average, or low AA, A, or B grade eggs but their appearance will help determine their best use in cooking. Other various defects can be observed but their exact causes are unknown and subject to speculation. In case you’re wondering, the color of an egg has nothing to do with its quality. Break your eggs out into a separate container to judge the thickness of the white and the firmness of the yolk. Egg quality can be improved by following methods: http://www.thepoultrysite.com/publications/1/egg-quality-handbook/5/internal-and-external-egg-quality/, http://www.aamu.edu/Academics/alns/foodandanimalsciences/Documents/Poultry%2011.28.11.pdf. Excluding weight, there are several other factors used to determine whether an egg is worthy of such a grade. Remember, B grade eggs will have yolks that are enlarged and slightly flattened. The three terms used are: Egg white or “albumen” usually has four layers, the chalaziferous, inner thin, thick, and outer thin. Off-center yolks can make pretty funny looking hard-cooked egg slices or deviled eggs. Good eggs have either no smell or a slightly sweet smell. On the inside, the checker looks to see if the white is firm, thick and clear. The cook does not need to be concerned with high, average, or low AA, A, or B grade eggs but their appearance will help determine their best use in cooking. Any type of phosphorous or musty odor indicates an inedible egg. Grade B eggs are not sold in supermarkets, but are used commercially in powdered egg products or liquid eggs. Web Design & At first the yolk just seeps a little and over time it becomes mixed with the white. On the other hand, if you break open and egg and the yolk is all mixed up with the white, causing the whole thing to be a murky mess, that’s a bad egg.