How to select and store hatching eggs before incubation

An incubator cannot repair an egg that is cracked, too old, overheated or badly handled. Batch quality before day one affects apparent fertility, early embryo loss, hatch timing and the number of viable chicks.

This guide covers chicken eggs intended for hatching. It provides a realistic method for small farms; flock health, local rules and instructions from the hatchery or supplier still take priority.

Preparation in six decisions

Stage	Main decision	Control sign
Collection	Collect early and often	Date and origin are known
Selection	Keep intact, normally shaped eggs	No crack, leak or major deformity
Identification	Do not mix histories	Batch, date and position recorded in pencil
Storage	Limit time, heat and moisture loss	Temperature and humidity monitored
Orientation	Protect the air cell and yolk position	Small end down; tray slanted when needed
Setting	Warm gradually and load one batch	No condensation; incubator already stable

1. Begin with the flock and nest

An egg can only be fertile when the breeder flock is actually producing fertile eggs. Age, health, nutrition, male-to-female ratio and mating conditions affect the result. A large number of clear eggs at candling may therefore come from the flock rather than the incubator.

Keep nests clean, dry and properly littered. Collect eggs regularly, more often in strong heat or when nests soil quickly. Prompt collection limits impacts, trampling, contamination and uneven development beginning under a hen or in a hot location.

Record at least:

• laying or collection date;
• flock or supplier;
• transport delays or shocks;
• planned setting date.

2. Choose eggs worth setting

Prefer clean, intact eggs of a size typical for the flock and a regular shape. Exclude from the hatching batch:

• cracked, leaking or unusually porous eggs;
• very thin, heavily ridged or misshapen shells;
• exceptionally small or large eggs;
• eggs heavily soiled with organic matter;
• eggs with unknown age or transport history when a documented batch is available.

Extreme size can be associated with unusual contents or poor tray fit. Do not select only by shell colour; colour mainly changes how easy an egg is to candle.

3. Do not turn washing into false reassurance

Mississippi State University Extension advises against washing hatching eggs and recommends prevention through suitable nests and frequent collection. Incorrect washing can damage the shell’s natural defences and help contamination move through shell pores.

Do not invent a recipe using water, detergent, disinfectant or veterinary chemicals. A professional sanitation procedure depends on the authorised product, concentration, temperature, contact time and operator protection.

For a small farm, the safest principle is to produce and select clean eggs. A cracked, leaking or foul-smelling egg cannot be rescued by surface cleaning.

4. Keep storage short

The FAO small-scale poultry guide recommends storing hatching eggs for no more than about seven days at 12–14°C and high relative humidity of 75–85 percent. Mississippi State also recommends no more than one week for most batches and gives a wider band of about 10–18°C with humidity around 70 percent.

These ranges do not mean that any point is equally suitable. They come from different systems and conditions. Keep four principles in view:

1. set eggs as soon as a coherent batch is ready;
2. avoid sunlight, very hot rooms and rapid changes;
3. avoid air so dry that excessive moisture is lost;
4. measure conditions instead of assuming a room is cool.

A household refrigerator is not automatically suitable. It may be colder than the recommended bands and can create condensation when eggs return to warm air. Measure the actual temperature, and keep hatching eggs away from strong-smelling products and contamination sources.

5. What if there is no climate-controlled room?

In a hot climate, shortening storage is usually more reliable than chasing a perfect number with an unstable improvised system.

• Use the cleanest, shadiest and most stable available location.
• Keep eggs away from hot roofs, sun-facing walls, motors and cooking areas.
• Use a simple thermometer and hygrometer to record minimum and maximum conditions.
• Protect trays from rodents, insects, dust and impacts.
• Plan smaller, more frequent batches instead of one large batch of very different ages.

Do not rely on evaporative cooling without understanding its performance in your climate: it behaves differently in dry air and already-humid air. Do not wet the shells directly.

6. Position and reposition eggs during storage

Store eggs small end down, which normally leaves the air cell at the broad end. When storage exceeds three or four days, Mississippi State recommends holding trays at an angle of about 30–45 degrees and changing the raised side daily.

For a small tray:

1. raise one side slightly;
2. change the raised side once each day;
3. move the tray rather than each egg when this reduces impacts;
4. use the same method and record the days.

Storage repositioning does not replace the regular turning required after incubation begins.

7. Prepare the incubator before moving the eggs

Run the clean incubator before loading until temperature, ventilation, turning and backup power are stable. Do not use valuable eggs to test an unfamiliar machine.

Also prepare:

• an independent thermometer;
• the water and reservoirs specified by the manual;
• the batch record;
• brooder space around day 21;
• a power-outage plan.

8. Warm gradually before setting

Moving eggs too quickly from cool storage to a warm incubator can create condensation on the shell. Bring the batch into a clean area and let it warm gradually toward room temperature according to the supplier’s or incubator manual’s procedure.

Do not warm eggs with hot water, a flame, a heater, full sun or a hot surface. Do not set an egg while condensation remains on it. Keep the batch identified, and avoid adding groups at different times when that would create multiple hatch dates in one small machine.

Minimum batch record

Information	Example field
Origin	Flock A / supplier
Collection	Date and approximate time
Collected quantity	Total before selection
Selected quantity	Intact, regular eggs
Storage	Days, min/max temperature, humidity
Transport	Duration, impact or unusual heat
Setting	Date, time and number loaded
First candling	Result around days 5–7

This record links results to the real age of the eggs. It prevents every low hatch rate from being blamed on the machine.

Frequently asked questions

Can I mix eggs collected over ten days?

The batch will have very different histories and older eggs will generally carry more risk. Prefer a short, documented window, or separate batches when your equipment and process allow it.

Must I fill the incubator to its maximum capacity?

No. Advertised capacity does not guarantee egg quality or backup energy. Our 36, 56/64 and 120 capacity guide helps size the real batch.

Can a dirty egg be washed and then incubated?

Improvised washing is not recommended. Improve nests and collection frequency, select clean eggs and obtain a professional sanitation procedure when your operation requires one.

A good start does not mean filling every space. It means setting, on the same day, a clean, intact, recent and traceable batch that has warmed gradually to the correct condition.