Buy graded eggs in cartons at a store that keeps them in refrigerated
cases. Federally graded eggs are identified with a shield-shaped
grademark that indicates the quality at the time of grading. If they
have been properly handled since grading, there should be little loss
in quality.
_Quality._—U.S. Grade AA (or Fresh Fancy) and Grade A eggs are
excellent for all purposes, but are especially good for poaching and
frying where the appearance of the finished product is important. Grade
B eggs are satisfactory for use in cooked dishes.
The grade of the egg does not affect its food value; lower grades are
as high in nutrients as top grades. Buy either white or brown eggs. The
color of the shell does not affect the nutritive value or quality of
the egg.
_Size._—Eggs are also classified by size according to weight per dozen.
Size is independent of quality; large eggs may be of high or low
quality and high-quality eggs may be of any size. Common market sizes
of eggs and the minimum weight per dozen:
U.S. Extra Large—27 ounces.
U.S. Large—24 ounces.
U.S. Medium—21 ounces.
U.S. Small—18 ounces.
The substitution of one size egg for another often makes little
difference in recipe results. However, in some recipes—for example in
sponge and angelfood cakes—the proportion of egg to other ingredients
is very important. For these recipes, it may be necessary to increase
the number of eggs if you are using a smaller size.