The "Standards of Exterior Quality for Individual Shell Eggs" and the overall consumer eye appeal of cartoned eggs govern each carton's placing and the written factors. This section provides a brief description of the standards (refer to the table for a summary of the standards). For further information, refer to the Egg-Grading Manual - Agriculture Handbook Number 75.
A participant should use a systematic order when evaluating the eggs in each carton according to the three categories: soundness, cleanness, and uniformity of color and size. The chart to the right gives a brief description of the categories and possible defects. A more complete description of each category follows below:
Checked or cracked - A check is an egg having a broken or cracked shell, but the shell membranes are intact and no leakage occurs. A check ranges from a plainly visible, dented check or crack to a very fine, hairline check (blind check) that often escapes detection. Checks significantly detract from the cartoned eggs' appearance.
Checks become detectable as eggs move through the market because eggs break during gathering, grading, packing, and transporting.
Body check - A body check is an egg whose shell cracked inside the hen's body and was repaired by additional calcium deposited over the cracked area, resulting in a ridged area/ Body checks detract from the cartoned eggs' appearance. (Grade B)
Irregular shape - An irregular shaped shell is unusual in shape. Although it has no effect on the interior quality of the egg, it deviates noticeably from the "ideal." The ideal egg is oval in shape, with one end larger than the other. The large end (air cell end) tapers toward the smaller end. Irregular-shaped shells are faulty in texture and strength and may have thin spots. Unusual shaped shells detract from the cartoned eggs' appearance. (Grade B)
Calcium deposits - Although it does not decrease the interior quality of an egg, any rough and elongated area of calcium deposits decreases egg shell strength. Calcium deposits on the shell detract from the cartoned eggs' appearance. (Grade B)
Definite ridges - Pronounced ridges affect the shape of the egg shell. They decrease shell strength and detract from the cartoned eggs' appearance. (Grade B)
A Clean egg shell is free from readily visible stains (permanent discoloration) or adhering (sticking, clinging) material. The shell is clean if it contains only very small specks, stains, or cage marks that do not detract from the eggs' appearance. A shell showing traces of processing oil is clean, unless the oil is soiled. Note: Do not misinterpret a water spot as a stain.
Adhering material - Adhering material is foreign matter that sticks to the shell and includes blood, yolk, albumen, or fecal material. Adhering material one millimeter or greater in area significantly detracts from the cartoned eggs' appearance. (Dirty)
Prominent stain - Prominent stains include moderate, localized stains covering more than 1/32 of the shell or scattered stains covering more than 1/16 of the shell. Prominent stains significantly detract from the cartoned eggs' appearance. (Dirty)
Slight stain -- Slight stains include moderate, localized stains covering less than 1/32 of the shell or scattered stains covering less than 1/16 of the shell. Slight stains detract from the cartoned eggs' appearance but not as much as adhering material/prominent stain. (Grade B)
The following guide may help visualize surface area dimensions of an egg shell:
Total surface area of a normal 2-ounce egg = 10 1/2 square inches.
1/32 of shell surface area measures approximately 9/16" x 9/16"
1/16 of shell surface area measures approximately 13/16" x 13/16"
1/4 of shell surface area measures approximately 1 9/16" x 1 9/16"
A uniform carton of eggs has all eggs equal in size and the same color.
Mixed Color - Shell color has no effect on interior quality and is not a factor of the standards. Eggs sorted and packed in one color ("whites" or "browns"), however, sell better than do "mixed color" eggs. A carton of mixed color eggs lacks consumer appeal. (Grade B)
Uneven Size - Egg size has no effect on the interior quality of the egg. Eggs sorted and packaged into uniform sizes, however, sell better than do eggs sold as "mixed sizes." A carton containing different sizes of eggs lacks consumer appeal. (Grade B)
This page has been adapted from the Poultry Science Manual For National FFA Career Development Events, third edition, provided by the National FFA Organization.