Eggs are excellent for main dishes because they contain high-quality protein, and are a good source of several important minerals and vitamins. When you serve eggs as an alternate for meat in a main dish, either allow more than 1 egg per person or add enough milk or cheese, as in cheese omelet, for example, to make up the difference.
Government-graded eggs are sold in cartons labeled with the grade (quality), size (weight), and date of grading. There are four U. S. grades—AA, A, B, and C. Grades AA and A have a large proportion of thick white, a firm high yolk, and a delicate flavor. They are often preferred for cooking in the shell, poaching, and frying. Grades B and C, which are less expensive than the two top grades, are a thrifty choice where appearance and delicate flavor are less important, as in Spanish omelet, gingerbread, or scrambled eggs with bacon.
Sizes of eggs and their minimum weights per dozen are:
| Jumbo | 30 ounces |
| Extra large | 27 ounces |
| Large | 24 ounces |
| Medium | 21 ounces |
| Small | 18 ounces |
| Peewee | 15 ounces |
Within any grade, large eggs usually cost more per dozen than smaller ones. Use the above weights to determine which size gives you the best return for your money. For instance, if medium eggs weighing 21 ounces are 56 cents a dozen (2⅔ cents an ounce) they are a better buy than large eggs weighing 24 ounces at 66 cents a dozen (2¾ cents an ounce).
Eggs are cheaper than meat as a source of main-dish protein when the price of eight large eggs is less than the price of a pound of meat with moderate amounts of bone and fat, such as rump roast. Or when the price of a dozen large eggs is less than the price of a pound of lean meat with little fat and bone, as round steak.
The color of the eggshell depends on the breed of hen and does not indicate the food value of the eggs. So do not pay a higher price for brown eggs than for white ones, or vice versa, with the idea that you are getting more food value.