There is no infallible mode of ascertaining the freshness of an egg
before you break it, but unless an egg is perfectly good, it is unfit
for any purpose whatever, and will spoil whatever it is mixed with. You
may judge with tolerable accuracy of the state of an egg by holding it
against the sun or the candle, and if the yolk, as you see it through
the shell, appears round, and the white thin and clear, it is most
probably a good one; but if the yolk looks broken, and the white thick
and cloudy, the egg is certainly bad. You may try the freshness of eggs
by putting them into a pan of cold water. Those that sink the soonest
are the freshest; those that are stale or addled will float on the
surface.
There are various ways of preserving eggs. To keep them merely for
plain boiling, you may parboil them for one minute, and then bury them
in powdered charcoal with their small ends downward. They will keep a
few days in a jar of salt; but do not afterwards use the salt in which
they have been immersed.
They are frequently preserved for two or three months by greasing them
all over, when quite fresh, with melted mutton suet, and then wedging
them close together (the small end downwards) in a box of bran, layer
above layer; the box must be closely covered. Charcoal is better than
bran.
Another way (and a very good one) is to put some lime in a large
vessel, and slack it with boiling water, till it is of the consistence
of thin cream; you may allow a gallon of water to a pound of lime.
When it is cold, pour it off into a large stone jar, put in the eggs,
and cover the jar closely. See that the eggs are always well covered
with the lime-water, and lest they should break, avoid moving the jar.
If you have hens of your own, keep a jar of lime-water always ready,
and put in the eggs as they are brought in from the nests. Jars that
hold about six quarts are the most convenient.
It will be well to renew the lime-water occasionally.