Candling Eggs

Candling is a pretty easy task.  The basics are a light source, a box with a hole and a dark room.  When you are incubating chicken eggs, you should typically candle twice.  Once around 7-10 days and then again around 15-18 days.  Candling allows you to verify egg development  so you can remove eggs that aren’t developing to prevent bacterial contamination in the rest of the eggs.  The first candling is a little more challenging because sometimes it is difficult to differentiate between the yolk and a developing mass.  If you candle closer to 9 or 10 days, it’s easier.  If you have dark shelled eggs, you may not even be able to seen anything until that point anyway.   By 15-18 days, it’s very apparent if there’s a chick in there or not.

You can purchase a commercial egg candler, make a fancy one yourself or make a basic, functional one out of items you have at hand.  I have chosen to make one with items I had on hand.  The things I used:  an empty tissue box and a flashlight.  I cut a hole the diameter of a quarter in the bottom of the box and place the flashlight through the opening at the top (the part where you remove tissues) and invert it so that I will place the egg on top of the hole, with the flashlight underneath it.

Homemade egg candler

The second time we candled the eggs my friend (the one who provided the eggs and who will be splitting the chicks with us) brought a vintage commercial egg candler that she received as a gift.  It was easier to use because it could be set on a flat surface so you had both hands for handling the eggs.

You need to candle relatively quickly.  The eggs shouldn’t be out of the incubator for more than 1/2 an hour.  It’s helpful to time your candling session around the time you would turn them.  It’s easiest to place all the eggs in a bowl so that you can remove one at a time from the bowl, candle it and replace it back in the incubator if it’s viable.  Make sure to make note of which side of the egg is facing up (x or o).  Then turn your light off and get to candling!  Dispose of any eggs that aren’t developing.  This is harder the first candling, but you should see a solid mass and a network of blood vessels and all of the eggs should be at similar stages of development.  The second time you candle, you will see an air-pocket at one end and most of the rest of the cavity taken up by the chick.

Egg candled at 18 days

*Sorry for the poor quality of these last two photos.  It’s very difficult to take a good candling picture!