When To Candle Eggs

Are you new to egg candling? Or maybe you just got into the poultry business, and you figured egg candling is part of the job? Whichever the case may be, we are here to help you learn important things like when to candle eggs.

Knowing when to candle eggs and when not to is crucial; randomly candling such eggs can affect its condition. For example, did you know that you should not candle eggs specifically between eleven and fourteen days of incubation? If you do, you can disrupt the embryo’s migration to the egg’s length axis.

when to candle eggs

Now, can you see how important it is to know when to candle eggs properly? Then, we’ll give you an in-depth guide on egg candling, when you should do it, and all that fun stuff. So, for starters, let us dissect the basics about egg candling.


What is Egg Candling?

Candling is a technique for seeing the maturation of an embryo within an egg. To do this, employ a strong light source behind the egg to reveal features through the shell. It got its name since the first light sources were candles.

A modern egg candle or candle lamp is a focused beam luminaire. LEDs are now recommended because of their highly bright, efficient, and very long lifespan. In addition, it eliminates the need to change bulbs and the convenience of small, portable, battery-powered devices.

You can directly use it right out of the socket. These LEDs also emit cool light rather than a lot of heat that can damage the embryo. With the high demand for broilers, we must take care of such eggs to meet such needs.


Importance of Egg Candling

Egg candling lets you monitor your embryos inside the egg. It monitors the rate of egg fertility, embryonic development, and weight loss. In addition, non-viable eggs, which can be sterile or die prematurely, can be identified and removed.

You can even avoid the risk of rotten eggs exploding and contaminating the herd with dangerous microorganisms. So you must know when to candle eggs to prevent these things from happening. Imagine losing all of your eggs just because you forgot to check on one; painful, right?

Candling your eggs does not harm them just because they are out of the incubator. Remember, the mother does not always sit on the eggs, right? It leaves it sometimes, so just imagine that time is you candling them for a while.

During hatching, the size of the air sacs should increase as water evaporates from the eggs. During hatching, eggs should lose about 13% of their original weight. If the humidity level is nearly correct, the airbags should increase on different incubation days. 

Do not be scared if the airbag is more prominent than usual; the incubator’s humidity may be too low. You should increase the incubator’s humidity to reduce the rate of water loss. If the airspace is smaller than average, the reverse applies.


When To Candle Eggs?

After 5 days of hatching, you can light the eggs and then light them every few days. You should do egg candling in the dark or dim lighting for best results. The candle should be held against the shell on the egg’s larger end next to the bladder. 

The ideal period for candling eggs is 7-10 days in the incubator. However, embryos are very fragile during the first week, so you have to wait until this critical period has passed. Then, after about a whole week, you can see more clearly what is happening. 

Rotation of eggs reveals dilation of blood vessels and development of embryos. Viable eggs will initially have small spots with an enlarged arterial network. So keep notes of these essential days on when to candle eggs.


When to Candle Eggs During Incubation? 

Make sure the eggs are healthy and undamaged before placing them in the incubator. Fertility is assessed every seven to ten days, and cleanses are removed. Then, you can do it again sixteen days before hatching. 

Remove dead or underdeveloped eggs. Otherwise, the newly hatched chicks may burst their eggs and create foul-smelling sediment. In addition, candling eggs before hatching may help identify defects in eggs that may prevent them from hatching. 

You can check for missing yolks, cracks, broken air sacs, or problems with the shell. Embryos often begin to develop and then stop. The seven-day indicator candle removes sawdust and prematurely dead eggs. 

Candling eggs the day before pecking can help get rid of late quitters. Knowing how many times you need to candle eggs is just as important as knowing when to candle eggs


Is Egg Candling Harmful to Eggs? 

No, this isn’t usually the case, but it can take too long or be careless. For example, leaving an egg on a hot light bulb for an extended time can damage the egg. Likewise, eggs can die if left in the incubator for extended periods. It is only a problem if you need to light a large number of eggs at once. However, the more candle eggs you use, the more likely they will break or be damaged. So be careful and put a soft towel under your work area.



In broiler production, egg candling is one of the processes involved. However, egg candling is not as simple as lighting eggs and seeing what’s happening inside. You have to know the right time on when to candle eggs, what to expect, and all those other things.

Leave a Comment