How to Candle Eggs

By “egg candling,” or placing a bright light behind your eggs, you can determine the age of your eggs and find imperfections such as hairline cracks and double yolks that prevent the eggs from being good candidates for hatching. Learn how to candle eggs on your homestead.

| May 30, 2013

Hatching and Brooding Your Own Chicks book cover

“Hatching & Brooding Your Own Chicks” by poultry authority Gail Damerow is the definitive guide to hatching healthy baby chickens, as well as ducklings, goslings, turkey poults, and guinea keets. Damerow addresses every possible challenge of the process: selecting a breed, finding the best incubator, ensuring proper set-up and sanitary conditions, understanding embryo development, and feeding and caring for newborn chicks in a brooder.

Cover Courtesy Storey Publishing

If you want to hatch your own eggs — to maintain a particular flock that is acclimated to your locale, to restore an endangered breed, or just for the fun of it — you should know how to candle them. In Hatching & Brooding Your Own Chicks (Storey Publishing, 2013), chicken expert Gail Damerow offers everything you need to know about the hatching process, as well as how to acquire and brood hatchlings. Taken from “Chapter 8: Eggs for Hatching,” this excerpt explains how to candle eggs by using candling devices to find hairline cracks, thin spots, and double yolks — all things you need to know in order to select the best eggs for hatching in your incubator.

You can purchase this book from the MOTHER EARTH NEWS store: Hatching & Brooding Your Own Chicks.

Not all of an egg’s qualities may be determined by looking at the outside of the egg. Detecting such things as hairline cracks, thin spots, and double yolks requires candling the eggs. You can learn how to candle eggs yourself. Egg candling means examining the contents of an egg by placing a bright light behind it, although I’d be surprised if anyone still uses candles.

Egg Candling Devices

Poultry-supply outlets offer various handheld devices designed specifically for the purpose. Most of them look like small flashlights with a plug-in cord. Although a battery-operated egg candler is available for candling eggs under a broody hen when no power is available, a small flashlight works at least as well as, if not better than, either a plug-in or battery-operated egg candler.

All you need is bright light that comes through an opening smaller than the diameter of the eggs you want to candle. If you have a too-big flashlight, cut a hole in a piece of cardboard and tape it over the business end of the flashlight, or tape a short piece of empty toilet-paper or paper-towel tube to the end in such a way that light only comes through the narrowed opening.

Such egg candling devices work best in a dark room. Hold the egg at a slight angle, large end to the light. Making sure your fingers don’t block the light, turn the egg until either you see something or you’re certain there’s nothing to see.

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