How and Why to Candle Eggs

When we first started the process of hatching our own eggs I thought the idea of candling seemed really simple, how hard could it really be? But it turns out how to candle eggs can be a little more tricky than you would think.

How to Candle Eggs - candling an egg with text overlay

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During the process of incubating eggs, there are a few different times that you want to candle your eggs to see what the development is. Why? Because you aren’t going to continue to incubate eggs that are not developing.

What to Use to Candle Eggs

What you use is going to depend on the size of your egg, and what you have for candling. My small incubator does have a built in candle which works great and is what I use now.

You want to have something that the eggs fit nicely on to, or that you can also wrap your hand around the make it tight-fitting. You can see a demonstration of this below in the photo where I was candling to test fertilization.

flashlight on your cellphone works great too, especially for smaller eggs like quail.
a flashlight – size depending on the size of your eggs
a candler

How to Candle Eggs

I do not and do not know anyone, that actually uses a candle to candle their eggs. This would be an older approach, before flashlights and candlers. You could very easily burn your eggs using a candle.

What you want to do is sit the egg on your light source as in the picture above. You want the light to not be shining out around but just through the egg.

Remember to take care when candling and to move quickly so that your eggs aren’t getting too cold. I remove one at a time to candle and then back into the incubator. Yes, it can be a slow process but I don’t want to cause problems with heat loss.

candling eggs - different stages of incubation

Why Candle Eggs

You want to candle eggs periodically to make sure they are developing so you can remove them from your incubator if they are not.

You will want to candle your eggs on days 7, 15 and the final time would be day 18 before you lockdown your incubator.

Not every egg is meant to be a chick, not all eggs get fertilized even from one hen. There can also be contamination that happens which will prevent an egg from developing. You definitely want to remove eggs that have been contaminated.

Remember to take care when candling and to move quickly so that your eggs aren’t getting too cold. You don’t want to candle them too often because this is going to increase the time they are out of the incubator away from that heat and humidity.