Purdue University Agricultural Extension Service
Mimeo P-39 March 1952 (III)
SHELL TEXTURE OF CANDLED EGGS ***as it affects the classifying of Eggs Candled in 4-H Judging Contests
The following specifications and descriptive terms are based on the ”U.S. Standards for Quality of Individual Shell Eggs.” They will be the basis on which shell quality will be considered along with interior quality when candled in 4-H conests. Note that shell cleanliness is not considered because it would be almost impossible to keep the eggs clean when they are handled by many contestants.
"A" Quality - Shell unbroken - any egg with a definite break, even though small, is
not classified as to quality.
Shell practically normal - the egg should be close to the usual ”egg shape”. Slight ridges that do not materially affect shape are permitted.
The shell should be of goo even texture and strength and free from rough areas or thin spots. Slight rough areas that do not materially affect texture and strength of shell are permitted.
"B” Quality - Shell unbroken
	Shell may be slightly abnormal - the egg may be somewhat unusual in
shape (quite spherical; no distinct large and small ends; must not be too long to fit into an egg case filler). It may show definite ridges, but no a pronounced ridge such as is common when a body check is healed over.
The shell may be slightly faulty in texture or strength; show a
reasonable amount of mottling; but it must show no pronounced thin spots or rough areas. In other words, the shell need not be perfect, but it must not be so weak that a slight tap with your fingernail would break it.
"C" Quality - Shell unbroken	,	,
Shell may be abnormal - the egg may be decidedly misshapen (long and narrow; lopsided). It may show pronounced ridges.
The shell may be faulty in texture and strength; show pronounced
mottling in which the spots may merge together; or show definite thin spots or rough areas.
DEFINITIONS
Body check. A body check is a healed over, cracked or broken shell usually observed by, a pronounced ridge encircling the egg. When held before a candle, the healed over cracks can be seen. An egg with a body check would classify as "C".
Blind check. A blind check is a cracked egg in which the crack in the shell is so fine that it is not readily seen by the naked eye except before the candle. This crack is not healed over. There is no leaking of the contents because the shell membranes are unbroken. Presence of a blind check can often detected by the dull sound noticeable when two eggs click together in the normal operation of handling eggs. An egg with a blind check would not be classified as to quality; it would go in with the ”cracks”.
Mottling. The presence of small spots in the shell, varying from the size of a pin point to nearly l/8 inch in diameter. Sometimes the spots merge together. Away from the candle, the spots appear somewhat like small grease spots.
Before the candle, they are quite readily seen since they let more light through
than does the rest of the shell. They are the result of an uneven of moisture in the shell and are influenced by the relative humidity in the
holding room.