How Do You Candle Chicken Eggs To Check For Development?

Free Ranging and Training Chickens...

“I’m planning to start a small backyard chicken operation, and I want to learn how to candle eggs properly. Can you explain the process and what I should look for during development? I’ve heard it’s crucial for ensuring healthy chicks. Any tips would be greatly appreciated!” Thanks, Elizabeth, Portland, Oregon, USA.

How Do You Candle Chicken Eggs To Check For Development?

Hey Elizabeth! It’s fantastic that you’re starting a backyard chicken operation in Portland. Candling eggs is indeed a crucial skill for ensuring healthy chicks, and I’m happy to walk you through the process. Let’s dive into the details of how to candle chicken eggs effectively and what to look for during various stages of development.

What is Egg Candling?

Egg candling is a method used to examine the interior of an egg without breaking the shell. The term “candling” comes from the original practice of holding an egg in front of a candle flame to illuminate its contents. Today, we use specialized lights or even flashlights for this purpose.

Why Candle Eggs?

Candling serves several important purposes:

  • Checking for fertility
  • Monitoring embryo development
  • Identifying potential problems (like blood spots or cracks)
  • Determining if an egg is fresh (for consumption)

For your backyard operation, Elizabeth, candling will primarily help you ensure that the eggs in your incubator are developing properly and allow you to remove any that aren’t viable.

When to Candle Eggs

You can candle eggs at various stages of incubation, but there are a few key times that are particularly useful:

  1. Day 4-7: To check for early development and fertility
  2. Day 10-14: To confirm continued development and identify any issues
  3. Day 18: Final check before the eggs enter lockdown for hatching

Equipment Needed for Candling

To get started with candling, you’ll need:

  • A dark room
  • A candling light (can be a specialized egg candler or a bright flashlight)
  • Clean hands or gloves
  • A pencil and notepad for recording observations

The Candling Process

Now, let’s walk through the step-by-step process of candling chicken eggs:

  1. Wash your hands thoroughly to prevent contamination.
  2. Set up your candling area in a dark room.
  3. Turn on your candling light.
  4. Gently remove an egg from the incubator, being careful not to rotate or shake it.
  5. Hold the egg with the larger end (where the air cell is located) against the light source.
  6. Slightly tilt and rotate the egg to view different areas.
  7. Look for signs of development (which we’ll cover in detail next).
  8. Record your observations.
  9. Return the egg to the incubator in the same position it was in originally.
  10. Repeat the process for all eggs, working quickly to minimize temperature changes.

What to Look for When Candling

Elizabeth, as you candle your eggs, you’ll want to look for specific signs of development at different stages. Here’s a breakdown:

Day 4-7:

  • Fertile eggs will show a small, spider-like network of blood vessels.
  • You may see a small dark spot (the developing embryo) attached to these vessels.
  • Infertile eggs will appear clear with just the yolk visible.

Day 10-14:

  • The network of blood vessels will be more pronounced.
  • The embryo will be larger and may move when candled.
  • The air cell at the large end of the egg should be visible.

Day 18:

  • The embryo will take up most of the egg, making it appear dark.
  • The air cell should be quite large.
  • You may see the embryo moving or even the beak “pipping” into the air cell.

Identifying Problems Through Candling

Candling can also help you identify potential issues with developing eggs:

  • Blood rings: A red circle visible in the egg, indicating early embryo death.
  • Clear eggs: No visible development, likely infertile or very early death.
  • Floating air cells: Air cell not in the correct position, which can cause hatching difficulties.
  • Cracked shells: May lead to bacterial contamination.

If you spot any of these issues, Elizabeth, it’s best to remove the affected eggs from your incubator to prevent potential contamination of healthy eggs.

Tips for Successful Candling

To make your candling process more effective:

  • Practice on infertile eggs first to get a feel for the process.
  • Use a powerful light source for clearer visibility.
  • Candle in a very dark room for best results.
  • Be gentle with the eggs to avoid damaging the developing embryos.
  • Keep candling sessions brief to maintain proper incubation temperature.
  • Keep detailed records of your observations for each egg.

Common Challenges in Egg Candling

As you start candling, Elizabeth, you might encounter some challenges:

  • Dark-shelled eggs: These can be harder to see through. Use a stronger light or look for the air cell and movement.
  • Difficulty distinguishing features: This comes with practice. Don’t hesitate to compare your observations with online resources or experienced chicken keepers.
  • Misinterpreting development stages: Keep a development chart handy for reference.

Beyond Candling: Ensuring Successful Incubation

While candling is crucial, remember that successful incubation involves more than just monitoring development. Pay attention to:

  • Temperature: Maintain a consistent 99.5°F (37.5°C).
  • Humidity: Keep it around 50-55% until the last few days when it should be increased to 65-70%.
  • Turning: Eggs should be turned at least 3 times daily until day 18.
  • Ventilation: Ensure proper air flow in your incubator.

The Importance of Record Keeping

As you go through this process, Elizabeth, I can’t stress enough how valuable good record-keeping can be. Note down:

  • The date each egg was laid
  • Observations from each candling session
  • Any unusual events or changes in incubation conditions
  • Hatch dates and success rates

These records will help you improve your process over time and could be invaluable if you decide to expand your chicken operation in the future.

Final Thoughts…

Elizabeth, candling chicken eggs is both a science and an art. It takes practice to become proficient, but it’s an incredibly rewarding skill that will significantly improve your success rate in hatching healthy chicks. Remember, every egg and every hatch is a learning experience. Don’t get discouraged if things don’t go perfectly at first – even experienced chicken keepers face challenges sometimes.

I hope this guide helps you get started with your backyard chicken operation in Portland. It’s exciting to think about the little peeps that will soon be running around your yard! If you have any more questions as you go along, don’t hesitate to reach out. Happy hatching!


Whether you're a complete beginner and don't know where to start, or you're a seasoned chicken keeping professional and just want practical "how to" advice on tap our guide to keeping chickens has got you covered...

Chicken Keeping Book

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}