On food and cooking the science and lore of the kitchen ( PDFDrive ) 165

Three different grades of eggs The AA egg has a high proportion of thick white and a firm, rounded yolk The A egg has a less thick albumen and a weaker yolk membrane, so it spreads more when cracked into a pan The B egg spreads even further, and its yolk membrane is easily broken All of these trends are probably part of the normal development of the egg The increase in alkalinity makes the albumen even less hospitable to invading bacteria and molds The thinning of the albumen allows the yolk to rise and the embryo to approach the shell, its early source of oxygen, and may make it easier for the embryo to tap the shell’s calcium stores A weaker yolk membrane could mean an easier attachment to the shell membranes And the larger air cell gives the chick more oxygen for its first few breaths These changes may be good for the chick, but they’re mostly bad for the cook A thinner white is runnier in the pan; a flabby yolk membrane is more likely to break when the egg is cracked open; and a large air cell means an irregular shape for a whole hard-cooked egg The only culinary benefit to an older egg is that it’s easier to peel Handling and Storing Eggs Producers handle eggs in ways that are meant to slow down the inevitable deterioration in quality Eggs are gathered as shortly after laying as possible and immediately cooled In the United States, they are then washed in warm water and detergent to remove the thousands of bacteria deposited on the shell during its passage through the hen’s cloacal opening In the past, the washed eggs were given a fresh coat of mineral oil to retard the loss of both CO2 and moisture; today, with most eggs getting to market just two days after laying and refrigerated during shipping ... laying as possible and immediately cooled In the United States, they are then washed in warm water and detergent to remove the thousands of bacteria deposited on the shell during its passage through the hen’s cloacal opening In the past, the washed eggs were... is that it’s easier to peel Handling and Storing Eggs Producers handle eggs in ways that are meant to slow down the inevitable deterioration in quality Eggs are gathered as shortly after laying as possible and immediately cooled... In the past, the washed eggs were given a fresh coat of mineral oil to retard the loss of both CO2 and moisture; today, with most eggs getting to market just two days after laying and refrigerated during shipping