Incubating Chicken Eggs Part 2- Setting and Candling

Welcome to the second post in the series “Incubating Chicken Eggs”! This three post series is designed to help you successfully incubate and hatch chicks on your homestead! If you aren’t quite to the stage of putting hatching eggs in the incubator, then you will want to jump back to Incubating Chicken Eggs Part 1. You will learn all about storing hatching eggs and preparing your incubator. If you already have eggs in the incubator, then fast forward to Incubating Chicken Eggs Part 3. That post covers lockdown and hatching. But for now, we are going to take a look at what it takes to set eggs in the incubator and what candling eggs is all about!

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How to Set Hatching Eggs in the Incubator

So, you have fertile hatching eggs, the incubator is all set up and has been test run, now let’s get those eggs cooking (in the incubator)! Follow along with these steps to get the fertile hatching eggs ready for incubation.

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

Then follow these steps:

#1. Prepare the Eggs:

• Gather the hatching eggs and have a secure way to manage the eggs, such as a soft basket or clean egg carton, then head to the incubator!
• If you were storing the hatching eggs and had them wrapped in plastic wrap, take the time to unwrap each egg.
• Use a bright flashlight to candle the eggs. How to candle eggs is discussed later on in this post.
• Number each egg using a soft lead 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. If you are nervous about marking the eggs you don’t have to do this step. Marking the eggs just helps you keep record of each egg’s development.
• Optional: Outline the air cell on each egg so you can track the growth of the air cell throughout incubation. Tracking air cell growth can help you monitor incubator humidity.
• Optional: Weigh each hatching egg and mark each egg’s weight on a chart. Tracking egg weight loss throughout incubation is another way to monitor proper humidity levels in the incubator.
• Manual Turning: If you will be manually turning the eggs throughout incubation, it may be helpful to make each egg with an X and an O on opposite sides so you can keep track of which way you turn the eggs.

#2. Set the Eggs in the Incubator:

• Quickly and carefully open the incubator and place each egg in its appropriate spot. In a Brinsea Mini Advance incubator, each egg sits in a shallow hole in the turning disk. In a Rcom incubator, the eggs set on a turning plate and are contained by guards that create channels for the eggs to lay in.
• The pointy end of the egg should always be below the rounded end of the egg. When eggs are laid on their sides, this should naturally occur.
• Close the incubator and allow it to re-heat and reach stable humidity levels.
• Resist opening the incubator any more than necessary. Set a countdown for yourself. It takes 21 days for a chicken egg to hatch and lockdown occurs on day 18. You will candle the eggs again on day 7 or day 10.
• 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 re-position the egg to allow it to turn properly.

There you have it, the eggs are in the incubator and the process of embryo development will begin within 48 hours! Now comes the truly hard part, waiting and resisting the urge to open that incubator too many times! In some incubator models, you will have to open the incubator periodically to refill the water containers for maintaining humidity.

Tips for Keeping Incubating Records

One important thing you can do while you wait is make sure you are keeping adequate incubating records. Keeping records throughout incubation is especially helpful for troubleshooting after the hatch and will help you improve your hatching system if you choose to incubate eggs many times in the future.

Keep a record for each egg on a piece of paper so you can mark its 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. Charts and graphs are helpful to make for tracking egg development, air cell sizes, and the weight of each egg if you are weighing them throughout incubation.

Having an incubating notebook or binder is an excellent idea if you plan on doing multiple hatches or if you want to keep all your incubating records together over the course of several spring hatches.

Make sure you head on over to The Trading Post to get printables and resources that will help you keep detailed incubating records! You’ll find journal pages, candling charts, egg weight charts, and more!

How to Manually Turn Hatching Eggs

Some incubators, especially cheaper ones, do not have an automatic turning system installed. If that is the case with your incubator, then you will have to manually turn the eggs 3-5 times a day. Turning the eggs is most important during the first 2 weeks of incubation (day 1-14). This is when the embryo is doing a majority of its growth and it is important that the embryo does not get stuck to the shell membrane during development.

After two weeks of incubation, you may choose to only turn the eggs once or twice a day until lockdown to limit how many times you have to open the incubator. Here is a brief guide on how to manually turn hatching eggs:

• 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 chalazae which holds the yolk in the center of the egg or it could cause the allantois sac to break, 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 stabilize quickly after each turning.

How to Candle Hatching Eggs

Candling time is always exciting! You get to take a peak into the incubating eggs and see what’s happening! Is there any embryo developing? Did something go wrong? Candling time is always an exciting and nerve-wracking day!

The purpose for candling hatching eggs is that it allows you to make note of any abnormalities in or on the egg and helps you monitor the development of the embryo. It helps you know which eggs in the clutch you set in the incubator are most likely to develop into chicks.

What You Need:

• a small, bright light
• 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. Eggs with dark colored eggshells will need a stronger light to penetrate through the shell color. You will candle the eggs three times throughout incubation. Each candling session will be performed the same way, you will just be looking for things. To candle hatching eggs, follow these tips:

• Make sure you have a secure way of managing the eggs when you candle them as you will be removing them all from the incubator at candling time. A clean egg carton or soft-lined basket often works well.
• Work quickly and carefully when candling the eggs. The longer the eggs are out of the incubator the more they will cool down and embryo development will be delayed.
• Candle each egg by holding it over a bright flashlight in a dark room.
• Hold the egg so that the blunt end is slightly at an angle from the tip of the flashlight. This angle prevents the air cell (which is located at the blunt end of the egg) from blocking the light.
• Once all the eggs have been candled, you will place them back in the incubator and make sure it stabilizes at the correct temperature and humidity again.

If any eggs are deemed as unfit for incubating or not developing, don’t place those eggs back in the incubator. Eggs that aren’t developing may rot and prevent all the other eggs in the incubator from developing.

Look for these things at each candling time:

Candling #1: Setting the Eggs

• yolk & air cell– the yolk will look like a fuzzy, dark blob near the center of the egg and the air cell should be located at the blunt end of the egg
• hairline cracks- means an egg is unfit for incubating as they can allow bacteria to get into the egg
• double yolks- double yolks almost never hatch and if they do the chicks will more than likely 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 so you know where the chick will ‘pip’
• 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
• blood spots or meat spots– often appear as dark spots in the white of the egg or on the yolk and make the egg unfit for incubating

Discard any eggs with hairline cracks, double yolks, blood spots, meat spots, or mottled shells. Set the remaining eggs in the incubator following the hatching egg setting guidelines we went through previously.

Candling #2: Day 7 or Day 10

The next period at which you will want to candle your eggs will be after 7-10 days of incubation. After you first set the eggs in the incubator, you will want to create an incubating calendar so you can keep track of when you candle them to check for development.

Some folks like to candle on day 7, which is one week into incubation. Others, including myself, like to candle at about halfway through incubation, which would be day 10. The choice is yours to make.

First, wash your hands! Then, quickly open up the incubator lid and leave it open to remove the eggs to a soft cushion or egg carton. Place the lid back on the incubator once all the eggs are removed. Take each egg and candle it in a dark room. Candle each egg and 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 (get rid of) 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 they are not removed, they could explode and contaminate your whole hatch.

Candling #2: Additional Candling Tips

While you have the eggs out for the second candling on day 7 or day 10, you can also monitor the air cell growth and weigh the eggs if you choose. Both of these things can help you determine if the humidity levels have been staying at the correct levels for proper moisture evaporation from the eggs.

Using an air cell chart that is scaled to the appropriate size for the eggs you are incubating 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. If you want, you can mark each egg’s air cell carefully with a soft lead pencil.

Weighing the eggs requires that you have a small digital egg weighing scale. It also requires that you weigh the eggs before setting them in the incubator so that you know what each egg’s beginning weight is and can make calculations based off each egg’s weight loss. Check out this guide on weighing hatching eggs if you choose to weigh the eggs you are incubating.

Once you are done candling/marking/weighing the eggs, place each egg carefully back into the incubator and close the lid. Make sure the incubator returns to the proper temperature and humidity levels. Candling times are also good times to refill the water container inside the incubator if needed.

When Do I Candle Hatching Eggs for the Third Time?

After initially determining which eggs have started developing and which ones don’t contain a developing embryo, you have the option of leaving the eggs be until lockdown (day 18) or of candling them one more time to see how development is progressing or to get another weighing session in.

If you want to candle your eggs one more time before lockdown, you can do so on day 10 (if you didn’t do so already) OR day 14. Day 14 would mark two weeks into incubation. I do not candle a second time because I like to minimize the amount of times I open my incubator and remove the eggs.

If you do choose to candle your eggs, look for similar signs as when you candled on day 7 or day 10. Once again, discard eggs that are undeveloped or contain a dead embryo.

A second candling does give you another opportunity to monitor the air cell sizes and egg weights. Again, both of these things can help you monitor proper humidity levels.

The last time at which you should candle your eggs would be on ‘lockdown’ day.  Lockdown and hatching is discussed in Incubating Chicken Eggs Part 3.

Get Ready for Hatch Day!

Well, we just covered two of the most exciting parts of incubating: putting the eggs in the incubator and candling them! Setting the eggs in the incubator starts the developmental process of the embryo. Candling the eggs lets you see which ones are developing. Both are very exciting milestones in the incubating process! By the time you have completed the second candling, you will know potentially how many chicks you might have hatch.

After setting and candling, you are on to lockdown and hatching! You should also start preparing for your chick by setting up the brooder!

Also, you can get full-time support from us throughout the incubation process and raising your chicks afterwards by joining our pioneer newsletter community! Plus, you’ll get access to our free ebook that’s all about raising chickens like a pioneer! That way, once your cute little fluff balls hatch, you can raise them using natural, sustainable homestead methods!

by Alexa