Incubating Part 2- Setting and Candling

Welcome to the second post in the series “Incubating”! We have already covered storing fertile hatching eggs and preparing your incubator, now it is time to get those eggs incubating!

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!

Setting Fertile Eggs

Once you have programmed your incubator and stabilized the humidity it is now time to set the eggs you have been storing! First and foremost, wash your hands! Always wash your hands before handling the hatching eggs to keep from introducing harmful bacteria onto the egg and possibly ruining your hatch. I like to write myself a sticky note to remind myself to wash my hands before opening the incubator.

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!

Gather your cushion and your egg carton and head to the incubator! Carefully remove each egg from the carton and place it on the cushion. Next, take a bright flashlight and candle the eggs. How to candle eggs is discussed later on in this post. Number each egg using a soft pointed #2 pencil. Do not use markers, sharpies, or any ink or paint based pens and pencils. Be careful not to press too hard on the shell when you are marking the egg.

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!

Keep a record for each egg on a piece of paper so you can mark it’s progress and any abnormalities. This can also help if you are hatching several different breeds at one time or if you want to keep track of what eggs came from what hens. On my Svart Hona eggs, I numbered each one and also placed the first letter of the name of the hen it came from next to the number. I am also hatching a lavender Cochin egg, so I marked her egg with a ‘C’ and a number so I could tell it apart.

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!

Once all the eggs have been candled, it is now time to place the eggs in the incubator! Quickly and carefully open the incubator and place each egg in it’s appropriate spot. In the Mini Advance incubator, each egg sits in shallow hole in the turning disk. The pointy end of the egg should always be below the rounded end of the egg. I placed my Svart Hona eggs with their pointy ends facing inward, this helps keep the rounded end above the pointy ends. Close the incubator and allow it to re-heat and reach stabile humidity levels. Resist opening the incubator any more then necessary. On my Mini Advance I went and programed it for 21 days and turned the turning mode to ‘Auto’.

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!

Watch the eggs when they first get turned by the incubator and make sure all of them turn properly. If an egg does not turn all the way, you may have to briefly open the incubator and reposition the egg to allow it to turn properly.

Some incubators, especially cheaper ones, do not have an automatic turner installed. If that is the case with your incubator, then you will have to manually turn the eggs 3-5 times a day. Turning is most important during the first week of incubation, so you might have to turn them 5 times a day for the first week. Mark each egg with an ‘x’ on one side and an ‘o’ on the other side, turn them so that the ‘x’s are facing up one time and the ‘o’s are facing up the next time. Never turn the eggs in a complete circle, as this could break the allantois sac which is vital to the embryo’s survival. With such frequent opening of the incubator, you will want to make sure the humidity and temperature stabilizes quickly after each turning.

Candling Eggs

The purpose for candling hatching eggs allows you to make note of any abnormalities in or on the egg and helps you monitor the development of the embryo.

Candling requires two items: a bright light and a dark room. There are many different candling devices that you can buy for candling your eggs, but any bright flashlight often works just as well. There are several periods in the incubation process in which you would want to candle your eggs. The first period being right before you set your eggs in the incubator.

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!

Before you place your eggs in the incubator, candle each egg by holding it over a bright flashlight in a dark room. Look for these abnormalities:

  • hairline cracks- allows for bacteria to get into the egg
  • double yolks- double yolks almost never hatch and if they do the chicks do not survive
  • misplaced air cells- misplaced air cell eggs can still be hatched, just make sure you mark where the air cell is located with a soft tipped pencil
  • mottling- if the egg looks splotchy and speckled then the shell is too thin and may allow harmful bacteria to enter the egg, it will also not provide enough calcium for the growing embryo

Discard any eggs with hairline cracks, double yolks, or mottled shells.

The next period at which you will want to candle your eggs is after 7 days of incubation. First, wash your hands! Then, quickly open up the incubator lid and leave it open. Take each egg and candle it in a dark room. Look for these signs:

  • development- a dark spot with a web of blood vessels surrounding it, undeveloped eggs will look clear
  • blood rings- a thin, irregular ring around the inside of the egg
  • dead embryo- will appear as a dark, cloudy shadow

Cull (throw away) any eggs that have blood rings, shadowed contents, or are undeveloped. If you are unsure if an egg is developing or not, mark it and leave it in the incubator. Keep an eye on it and make sure it does not begin to rot. Rotting is a sure sign that the egg is truly not fertile or developing. Make sure none of your eggs smell bad or have disgusting substances oozing from their shells. Eggs that smell bad or contain dark substances are filled with bacteria and should be removed immediately. If not removed they could explode and contaminate your whole hatch.

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!

This Svart Hona egg is developing because you can see the black dot surrounded by blood vessels. The air cell is also the correct size and properly positioned.

You can also take note of each egg’s air cell size, which indicates if your humidity is correct. Using an air cell chart is helpful when monitoring the air cell size. If the air cell is smaller then normal, then your humidity is too high, if it is larger then normal, then the humidity is too low. Mark each egg’s air cell carefully with a soft #2 pencil. Place each egg carefully back into the incubator and close the lid.

The following PDF is an egg air cell chart that I use. You can download it for free by clicking on the following words: air cell chart

Some people like to candle their egg again after two week of incubation. I do not because I like to minimize the amount of times I have to open my incubator. If you do choose to candle your eggs, look for similar signs as when you candled the first time. Once again, discard undeveloped or dead embryo eggs. A second candling does give you another opportunity to monitor the air cell sizes. Mark each egg’s air cell size again and place each egg back into the incubator.

The last time at which you should candle your eggs would be on ‘lockdown’ day.  This will be discussed in the next post in this series!

by Alexa

Incubating Part 2- Setting and Candling: Learn the basics of putting fertile chicken eggs into the incubator along with how and when to candle them!