A Note Before You Begin

The information provided below is based on incubation practices that have consistently produced successful hatches within our own breeding program. This guide is intended as a helpful resource rather than a complete incubation manual. We strongly encourage all customers to carefully read and follow their incubator manufacturer's instructions and conduct their own research before setting eggs.

Successful incubation depends on many factors, including incubator accuracy, humidity management, egg handling, environmental conditions, and operator experience. Improper incubation practices can significantly reduce hatch rates.

At Birch Acres Homestead, we routinely achieve fertility rates between 90% and 100% and see similar hatch rates under our own incubation conditions. However, as outlined in our policies, we cannot and do not guarantee fertility or hatch-ability once eggs leave our farm. If you have eggs with detached air cells we do have a recommended guide below dedicated to shipped eggs with detached or damaged air cells.

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Before Setting Your Eggs

• Your incubator should be operating at stable temperature and humidity levels for a minimum of 24 hours before eggs are set. Refer to your incubator's instruction manual for specific recommendations.

• Upon arrival, shipped eggs should be rested for 24 hours with the pointed end facing downward before incubation.

• Prior to setting, candle each egg and inspect for detached or loose air cells. Loose air cells are common in shipped eggs and are usually caused by movement during transit. While they do not affect fertility, they may require additional care during the first few days of incubation.

• For shipped eggs with loose air cells, many breeders find it beneficial to incubate without turning for the first 24–48 hours to allow the air cell to stabilize. Incubators equipped with upright egg turners can be particularly helpful, as they keep the air cell positioned at the top of the egg.

• We highly recommend using at least two thermometers and hygrometers within your incubator. Digital units are preferred, as they tend to provide more consistent and accurate readings. Having backup monitoring equipment can help identify equipment failures before they affect your hatch.

Days 1–17

Temperature

• Forced-air incubator (with fan): 99.5°F (37.5°C)

• Acceptable range: 99°F–100°F

• Still-air incubator (without fan): 100°F–101°F

Maintaining a consistent temperature is one of the most important factors in achieving a successful hatch.

Humidity

Humidity should generally be maintained between 30% and 55% during the first 18 days of incubation.

The ideal humidity level will vary depending on your incubator and environment. Air cell development provides the best indication of whether humidity levels are appropriate. Air cells should be monitored during candling to ensure proper moisture loss throughout incubation.

Turning Eggs

Eggs must be turned regularly throughout incubation.

We strongly recommend using an automatic egg turner and checking periodically to ensure it is functioning correctly.

If turning eggs by hand:

• Turn eggs an odd number of times daily (3, 5, or 7 times).

• Ensure that the side facing upward in the morning is facing downward by the end of the day.

• Avoid leaving eggs un-turned for more than 8 hours.

Regular turning prevents the developing embryo from adhering to the shell membrane and promotes healthy development.

Candling

Candling can begin around Day 7.

When candling, look for:

• Visible blood vessels

• A small dark embryo

• Progressive growth of the air cell

By approximately Day 10, movement may be visible within developing eggs.

As embryos mature, less light will pass through the shell and the egg will appear progressively darker. By Day 18, the air cell should remain visible while the rest of the egg appears largely dark.

Candling Dark Eggs

Marans eggs and other heavily pigmented or heavily bloomed eggs can be difficult to candle during early development.

In these cases, air cell growth and overall shell darkness are often better indicators than visible blood vessels. By approximately Day 12, a normally developing egg will generally exhibit appropriate air cell growth and a noticeably darker appearance compared to infertile eggs.

Days 18–19 (Lock-down)

At Day 18:

• Stop turning eggs.

• Remove automatic egg turners.

• Candle eggs one final time.

• Remove eggs that clearly failed to develop or experienced early embryo mortality.

If you are uncertain about an egg's viability, it is usually best to leave it in the incubator.

Increase humidity to approximately 65%–70% and begin lock-down.

Once lock-down begins:

Do not open the incubator unless absolutely necessary.

Opening the incubator allows humidity to escape, which can cause internal membranes to dry prematurely. This may prevent chicks from properly rotating and "unzipping" during hatch.

Patience during lock-down is often rewarded.

Day 21 – Hatch Day

Leave the Chicks Alone

One of the most common mistakes new hatchers make is opening the incubator too soon.

Allow hatched chicks and unhatched eggs to remain undisturbed.

Not all chicks hatch at the same time. Some may emerge hours before others, and this is completely normal.

Newly hatched chicks retain nutrients from the yolk sac and can safely remain in the incubator for up to 72 hours while additional chicks finish hatching.

Opening the incubator prematurely benefits the hatched chicks very little while potentially harming those still working to hatch.

Moving Chicks to the Brooder

Once all chicks are dry, active, and fluffy, they can be moved to a prepared brooder.

Your brooder should already be warmed and ready before hatch day.

Unhatched Eggs

Before discarding any unhatched eggs, candle them to check for signs of development or movement.

Late hatchers occasionally occur, particularly when incubation temperatures fluctuate slightly during development. In our experience late hatchers do not hatch and assisting with hatching them is not recommended.

Final Thoughts

Every incubator, hatching environment, and poultry keeper is different. Small variations in room temperature, humidity, incubator design, elevation, and management practices can influence hatch results.

Our hatching room is located in our basement, where we incubate at 99.5°F and maintain approximately 55% humidity during the first 18 days. Under these conditions, we routinely achieve hatch rates averaging 90% or higher across our breeding program.

The key to successful incubation is consistency, patience, and careful observation.

Most importantly—enjoy the experience. There is nothing quite like hatch day.

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Incubating Hatching Eggs with Detached Air Cells

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Understanding Detached Air Cells

Detached air cells are one of the most common challenges encountered when incubating shipped hatching eggs. While they can reduce hatch-ability, they do not necessarily prevent a successful hatch. At Birch Acres Homestead, we have successfully hatched many chicks from eggs with detached air cells and have had customers report excellent hatch rates despite shipping-related air cell damage.

A detached air cell occurs when the membrane forming the air pocket at the large end of the egg becomes separated due to movement, vibration, or rough handling during transit. Instead of remaining fixed in place, the air cell may shift, roll, or move freely within the shell.

Because the air cell plays a critical role in oxygen exchange during the final stages of development, special care should be taken when incubating eggs exhibiting this condition.

Identifying Detached Air Cells

Before setting shipped eggs, allow them to rest for 12–24 hours with the pointed end facing downward.

After resting, candle each egg in a dark room using a bright candling light.

A normal air cell will remain fixed at the large end of the egg and show little to no movement when the egg is gently rotated.

A detached air cell may:

• Shift position when the egg is tilted.

• Appear irregularly shaped.

• Float or roll within the egg.

• Change position as the egg is rotated.

If the air cell appears unstable or moves freely, it is likely detached.

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Recommended Incubation Practices

Allow Eggs to Rest

Shipped eggs should be rested for 12–24 hours before incubation.

Place eggs with the pointed end down in a cool, stable environment between 60°F and 70°F. This resting period allows the contents of the egg to settle and gives the air cell an opportunity to stabilize before incubation begins.

Incubate Upright

For eggs with detached air cells, we recommend incubating upright with the large end facing upward.

Rather than immediately placing eggs in a horizontal automatic turner, leave them standing upright in an egg carton or incubator tray for the first 24–48 hours.

This positioning helps encourage the air cell to settle back into its natural location.

If your incubator uses upright turning racks, these can be particularly beneficial when incubating eggs with detached air cells.

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Reduce Turning During Early Incubation

Excessive movement during the first few days can further destabilize a detached air cell.

For the first 48 hours:

• Leave automatic turners turned off.

• Keep eggs upright.

• Avoid unnecessary handling.

If turning manually, gently tilt eggs no more than 45 degrees several times daily.

After the first week of incubation, normal turning schedules can typically be resumed.

Maintain Proper Temperature and Humidity

Temperature and humidity become even more important when incubating eggs with detached air cells.

Recommended incubation conditions:

Days 1–18

• Temperature: 99.5°F in a forced-air incubator

• Humidity: 45–55%

Lock-down (Days 18–21)

• Humidity: 65–75%

Proper ventilation should be maintained throughout incubation to support oxygen exchange and healthy embryo development.

Candle Throughout Incubation

Regular candling helps monitor embryo development and air cell stability.

We recommend candling on:

• Day 7

• Day 14

• Day 18

Look for:

• Strong blood vessel development

• Active embryo growth

• Appropriate air cell expansion

• Signs that the air cell has stabilized

Remember that darker eggs, such as Marans eggs, can be difficult to candle early in development. In these cases, monitoring air cell growth is often more useful than attempting to identify visible blood vessels.

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Lock-down and Hatch Day

Detached air cells can occasionally cause chicks to position improperly within the shell, making the hatch process more challenging.

For this reason, we recommend leaving eggs upright during lockdown whenever possible.

As hatch day approaches:

• Increase humidity to 65–75%.

• Avoid opening the incubator unnecessarily.

• Allow chicks to hatch without intervention whenever possible.

Occasionally, a chick may pip away from the air cell due to improper positioning. While this can reduce hatch success, intervention should only be considered after careful assessment and only when absolutely necessary.

Patience is often the best approach.

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Improving Your Chances of Success

While detached air cells can present additional challenges, many eggs still hatch successfully when given appropriate care.

To maximize hatch-ability:

• Rest eggs before setting.

• Incubate upright.

• Minimize turning during the first 48 hours.

• Maintain stable temperature and humidity.

• Monitor development through regular candling.

• Avoid opening the incubator during lockdown.

Most importantly, remember that detached air cells are a shipping-related issue rather than a fertility issue. An egg with a detached air cell can still contain a healthy, viable embryo and may hatch successfully with proper incubation practices.

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Final Thoughts

Every incubator, environment, and hatch is different. Detached air cells require additional patience and management, but they do not automatically mean an egg is lost.

We encourage poultry keepers to focus on consistency, observation, and sound incubation practices. Even eggs that appear compromised upon arrival can sometimes surprise you on hatch day.

With careful handling and a little patience, many shipped eggs with detached air cells can still develop into healthy, vigorous chicks.

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Please Note

The purpose of this article is to educate and provide information based on our experience and research. It is not intended to persuade readers to adopt or abandon specific poultry management practices. Every flock, incubator, and hatching environment is unique.

We encourage all poultry keepers to conduct their own research, evaluate their individual circumstances, and make informed decisions that best support their flock and management goals.

The information provided is intended to support thoughtful decision-making and help poultry keepers achieve the best possible outcomes from their hatching eggs.

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For More Information

• Damerow, Gail. The Chicken Health Handbook. Storey Publishing, 2016.

• Mattocks, Jeff. Niche Poultry: Feeding and Management. 5th ed., The Fertrell Company,2021.

• "The Effect of Tremulous Air Cells Upon the Hatchability of Eggs." Knox, Charles W., and Marlow W. Olsen. National Agricultural Research Center, Beltsville, Maryland, presented for publication on December 5, 1935.

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Happy Hatching from The Birch Acres Family!