Author: Anna & Mark

Candling is a way of getting
a sneak preview of hatching day, figuring out as early as day 8 whether
your eggs are fertile and growing.  Some experts will tell you
that candling is mandatory since infertile eggs can explode in the
incubator and take out your other eggs.  At the other extreme,
another batch of experts asserts that their hatch rates improved
drastically after they stopped candling since the time out of the
incubator and the heat of the lamp can harm the tender embryo.  I
opted to go ahead and candle, but used an LED light and kept the eggs
out of the incubator only a minute apiece to minimize chances of
killing my chicks.



When it comes right down to
it, candling is absurdly simple.  Just wait until it’s totally
dark (I wasn’t able to candle once the moon came out), then hold the
flashlight under the egg and cup your hand around the two so that no
light leaks out.  With white eggs, it’s pretty easy to see what’s
inside, but brown eggs block more of the light, so give your eyes a few
seconds to adjust to the darkness.  It can help to look at the egg
out of the corner of your eye, and rotate the egg gently until you can
see something.



The easiest thing to see is
the air pocket, a paler area at the blunt end of the egg.  At day
eight, you will probably also be able to see two dark blobs in the main
part of the egg — the eye and the chick’s body.  These two blobs
may look separate because the neck is thin and doesn’t block the light
very much.  I wasn’t able to get any photos in the dark, so I’ve
snagged a bunch of images for this post to illustrate what I’m talking
about — just click on a photo to see the source (and for more
information about candling.)



Bad eggs can look very
variable.  Unfertilized eggs will be clear with no dark areas and
those that were fertile but died young will have blood spots or blood
rings.  Cloudy eggs that are uniformly dark inside except for the
air pocket may mean that your egg died between day 10 and 16 (if you’re
candling later than day 8, of course.)  On the other hand, it can
be tough to see inside brown eggs as the chicks get larger, so don’t
assume that because it looks dark in there on day 20, your chick is
dead.



I’m a beginner at
candling, so I wasn’t entirely sure what I was seeing, but I’m pretty
sure that at day eight, five of my
seven eggs were alive.  If I’d been smart, I would have
numbered my eggs (marking on the shell with a pencil) and kept notes so
that I’d know if I guessed right at hatching time.  This time
around, I didn’t feel confident enough to remove any eggs that I
thought might be dead, but I’ll keep better notes and learn more for
the next batch.

Learn more about the pros and cons of
candling in my 99 cent ebook.



Permaculture
Chicken: Incubation Handbook walks beginners through perfecting the
incubating and hatching process
so they can enjoy the exhilaration of the hatch without the angst of
dead chicks. 92 full color photos bring incubation to life, while
charts, diagrams, and tables provide the hard data you need to
accomplish a hatch rate of 85% or more.

Remember how you can tell if
an egg is too old to eat with a float test?  You can use a similar test on day 23 or 24 with eggs that haven’t hatched to make sure the chicks inside are really dead.

The first step is to wait until most of your eggs have hatched.  I like to wait 24 hours after the last chick comes out of the shell, then take a close look at the remaining eggs to make sure none of them has pipped or been cracked.  (You don’t want to do a float test on a pipped egg or the chick will drown.)  This test is mildly traumatic to a chick inside an unpipped egg, so there’s no reason to risk it until you’re getting ready to toss the unhatched eggs.

Now fill a container with water that’s roughly baby bottle temperature — warm enough that you
can barely feel it when touched to the underside of your wrist.  (This is the same temperature water you use when proofing yeast for bread, about 100 degrees Fahrenheit.)  Wait until the water has stopped moving in the container, then take an egg out of the incubator and carefully lower it into the water with a spoon.

If your egg sinks to the bottom, it was probably infertile from the beginning and is definitely
a dud now.  If it floats, take a careful look at the floating pattern.

Does the big end stick up above the water with the narrow end pointing straight down?  Your egg is probably a “yolker” that either was a dud from the beginning or died young.

On the other hand, if your egg floats at more of an angle, almost horizontally, the chick might be alive inside.  (The chick is definitely still alive if the egg starts to move around on its own.)  Carefully take the egg out of the water, wipe it dry, and pop it back in the incubator for another day or two.

In the past, I’ve been guilty of pulling late hatchers out of the incubator prematurely, but with this float test in my arsenal, I suspect my hatch rate will continue to rise.