What's the difference between Large Grade A eggs and Large Grade AA eggs?

The “Large” refers to the size. The A or AA is the grade and refers to the quality and appearance of the egg white and yolk
From the USDA site:

“U.S. Grade AA eggs have whites that are thick and firm; yolks that are high, round, and practically free from defects; and clean, unbroken shells. Grade AA and Grade A eggs are best for frying and poaching where appearance is important.

U.S. Grade A eggs have characteristics of Grade AA eggs except that the whites are “reasonably” firm. This is the quality most often sold in stores.”

I think I’ll have a couple of eggs for breakfast today.

According to the US Department of Agriculture standards: AA quality eggs – The shell must be clean, unbroken, and practically normal. The air cell must not exceed 1/8 inch in depth, may show unlimited movement, and may be free or bubbly. The white must be clear and firm so that the yolk is only slightly defined when the egg is twirled before the candling light. The yolk must be practically free from apparent defects.

A quality eggs – The shell must be clean, unbroken, and practically normal. The air cell must not exceed 3/16 inch in depth, may show unlimited movement, and may be free or bubbly. The white must be clear and at least reasonably firm so that the yolk outline is only fairly well defined when the egg is twirled before the candling light. The yolk must be practically free from apparent defects.

http://www.ams.usda.gov/AMSv1.0/getfile?dDocName=STELDEV3004376

Here is a guide to the grading of eggs.

It’s pretty clear that AA grade eggs would be wasted on me. I usually make omelets and throw half the yolks away to reduce cholesterol. I will start looking for Grade B eggs – someone’s got to eat them.

‘Worriedguy’ is close, but, this is what my book says….
Grade AA eggs are the fancy variety. They are uniformly sized & have as near perfectly formed shells as possible. When opened, an AA egg will cover a small area. The white will be thick and stand high. The yolk is firm & high.

Grade A eggs will cover a moderate area when opened on a flat plate. Their white portion will be reasonably thick and the yolk will stand fairly high. Both AA & A have ‘eye’ appeal.

Grade B eggs will cover a wide area when opened and will have a small amount of thick white and a greater amount of thin white. The yolk is somewhat flattened & enlarged.

Grade C eggs will cover a very wide area when opened. There will be little or no thick white surrounding the yolk. The yolk itself will be flat and greatly enlarged. Both B & C are used for sauces & cakes.

Where do these differences come from? Is someone harboring Grade C chickens?

The more A’s the better.

Just a llittle bit bigger egg than an A rating.

What’s been referenced above as far as how much the egg spreads when opened on a plate or pan, that’s what I notice. I love eggs over easy and notice how an egg hits the pan, how much space it takes up, how the white sets up and how plump the yolk is.

OK, so how do they know what the whites and yolks are going to look like (in order to classify the eggs) without cracking the egg open?

Is there an egg school? The more A’s you get, the better? And I’ll bet somebody gets paid to make the decisions. Seriously, I’ll get the grad AA’s when I want an egg dish where looks count. Not for omelets, egg salad, eggs in cheese sauce. Poached and gorgeous, yes. Thanks for all the info.