The Complete Guide to Egg Incubators and Hatching

Before You Start — What Incubation Requires

Incubation is a twenty-one-day commitment for chickens (twenty-eight days for most duck breeds) that requires daily attention. You will need to monitor temperature and humidity, turn eggs (unless using an automatic turner), candle eggs to check development, and have a brooder ready before hatch day.

Expect imperfect results. A hatch rate of sixty to eighty percent from good-quality fertile eggs in a well-managed incubator is considered successful. One hundred percent is unusual. Some eggs will be infertile. Some embryos will fail to develop. Some fully developed chicks will fail to hatch. This is normal biology, not necessarily a failure of your equipment or technique.

Have a plan for cockerels. Approximately half of all hatched chicks will be male. You cannot reliably determine sex before hatching. If you cannot keep cockerels (roosters), have a plan for rehoming them before you set a single egg.

Sourcing Fertile Eggs

Fertile eggs can be sourced from your own flock (if you keep a rooster or drake), from local breeders, or by post from specialist hatcheries and breeders.

Freshness matters. Fertile eggs should ideally be set within seven days of laying. Fertility declines with each day of storage. Store fertile eggs in a cool room (approximately 12–15°C / 54–59°F) at a slight angle, turning them daily, until you are ready to incubate. Do not refrigerate — it is too cold.

Shipped eggs carry additional risk. Postal handling can dislodge the air cell and damage the delicate internal structures. Allow shipped eggs to rest for twenty-four hours at room temperature, pointed end down, before setting them in the incubator. Hatch rates from shipped eggs are typically lower than from locally sourced eggs.

Incubator Types — Manual Versus Automatic

Manual incubators require you to turn the eggs by hand at least three times daily (ideally five times, always an odd number so the egg rests on a different side each night). They are less expensive but demand significantly more time and attention. Manual turning carries a higher risk of inconsistency — missing a turning, or turning at irregular intervals, reduces hatch rates.

Automatic incubators include a motorised egg-turning mechanism that rotates the eggs at regular intervals (typically every one to two hours). This eliminates the single most time-consuming and error-prone element of incubation. For most keepers, automatic turning is the most valuable feature an incubator can have.

Semi-automatic incubators include a turning cradle that you tilt manually (by shifting a lever or rod) rather than individually turning each egg. This is faster than turning each egg by hand but still requires your attention multiple times daily.

Still-Air Versus Forced-Air Incubators

Still-air incubators have no internal fan. Heat rises naturally, creating a temperature gradient from top to bottom. The top of the incubator is warmer than the bottom. This means egg position matters — the temperature at egg level is what counts, not the temperature at the top of the unit. Still-air incubators are less expensive but less consistent. Temperature variation across the incubator can be significant, leading to uneven development.

Forced-air incubators include an internal fan that circulates air evenly throughout the chamber. This eliminates hot and cold spots, providing consistent temperature across all eggs regardless of position. Forced-air incubators are more reliable and are recommended for consistent results.

The temperature setting differs between the two types. Forced-air incubators should be set to 37.5°C (99.5°F). Still-air incubators should be set slightly higher — approximately 38.3°C (101°F) — measured at the top of the eggs, because the temperature at egg level in a still-air unit is lower than at the top where the thermometer typically sits.

Temperature — The Most Critical Variable

Incubation temperature must be maintained within a very narrow range. The target for a forced-air incubator is 37.5°C (99.5°F) throughout the entire incubation period (for both chicken and duck eggs).

Consequences of incorrect temperature. Even small deviations matter. Sustained temperatures above 38.3°C (101°F) damage embryos and cause deformity or death. Temperatures above 39.4°C (103°F) are rapidly fatal. Sustained temperatures below 36.7°C (98°F) slow development and may kill embryos. Brief, minor fluctuations (such as opening the incubator for candling) are tolerable — it is sustained deviation that causes harm.

Use a separate thermometer. Do not rely solely on the incubator's built-in display. Verify the temperature with an independent thermometer placed at egg level. Digital thermometers with probe sensors are accurate and inexpensive. The internal display on budget incubators can be inaccurate by a degree or more — a meaningful error at this scale.

Humidity — The Second Critical Variable

Humidity during incubation controls the rate at which moisture evaporates through the eggshell. This evaporation creates the air cell at the broad end of the egg — the pocket of air the chick breathes from just before hatching.

Days one to eighteen (chickens) / days one to twenty-five (ducks): Target humidity of 45–55%. This allows appropriate moisture loss, creating an air cell of the correct size. If humidity is too high, the air cell is too small — the chick cannot position itself correctly for hatching and may drown in excess fluid. If humidity is too low, the air cell is too large — the membranes dry out and shrink-wrap around the chick, trapping it.

Lockdown (final three days for chickens / final three days for ducks): Increase humidity to 65–70%. The higher humidity softens the shell membrane, making it easier for the chick or duckling to break through.

Duck eggs require particular attention to humidity. In the wild, ducks leave the nest daily to swim, returning with damp feathers that transfer moisture to the eggs. Some experienced duck hatchers mist duck eggs with lukewarm water daily from day seven onward, or briefly cool and mist them to mimic this natural process. This is not essential with modern incubators but can improve hatch rates.

Monitoring humidity. A hygrometer (humidity gauge) is essential. Many incubators include one, but as with thermometers, verify with an independent instrument. Humidity is adjusted by adding or removing water from the incubator's water channels or reservoirs.

Egg Turning — Why It Matters

In nature, a broody hen turns her eggs instinctively — shifting, rotating, and repositioning them throughout the day. This prevents the developing embryo from adhering to the shell membrane, ensures even heat distribution, and supports proper development of the circulatory system.

Minimum turning frequency: Three times daily if turning by hand (five times is better). Always turn an odd number of times per day so the egg rests on alternate sides on consecutive nights.

Automatic turners rotate eggs every one to two hours — far more consistently than any human schedule — and are the single most impactful upgrade from a manual incubator.

Stop turning three days before the expected hatch date (day eighteen for chickens, day twenty-five for ducks). This allows the chick to orient itself into the hatching position — head tucked under the right wing, beak pointing toward the air cell at the broad end of the egg.

Setting Up Your Incubator

Run the incubator empty for at least twenty-four hours before adding eggs. This allows the temperature and humidity to stabilise and confirms the equipment is functioning correctly. Adjust settings during this stabilisation period, not after eggs are loaded.

Place the incubator in a room with a stable temperature — away from direct sunlight, draughts, radiators, and windows. Room temperature fluctuations directly affect the incubator's ability to maintain consistent internal conditions.

Ensure the surface is level. A tilted incubator creates uneven water distribution in the humidity channels and may affect automatic turning mechanisms.

The Incubation Timeline — Chicken Eggs

Days one to seven. Set eggs, begin turning. The embryo is developing but invisible without candling. Maintain 37.5°C (99.5°F) and 45–55% humidity.

Day seven to ten. First candling. Fertile eggs show a dark spot (the embryo) with a network of blood vessels radiating outward — often described as a "spider." Clear eggs (no development) are infertile or early failures — remove them.

Day fourteen. Second candling. The embryo should fill approximately half the egg. The air cell at the broad end should be clearly defined and growing.

Day eighteen — Lockdown. Stop turning. Increase humidity to 65–70%. Do not open the incubator from this point unless absolutely necessary. The chick is positioning itself for hatching.

Day twenty-one — Hatch day. Chicks pip (crack the shell from inside), then gradually work their way around the shell (zipping) before pushing free. The process takes five to twenty-four hours per chick. Do not help — intervening too early can cause fatal bleeding from blood vessels still connected to the shell.

The Incubation Timeline — Duck Eggs

Duck eggs follow the same principles but with a longer timeline (twenty-eight days for most breeds, thirty-five days for Muscovy ducks) and slightly higher humidity requirements.

Days one to twenty-five. Maintain 37.5°C (99.5°F) and 50–55% humidity. Turn eggs as for chicken eggs. Some keepers mist duck eggs with lukewarm water daily from day seven and briefly cool them (fifteen to thirty minutes) to mimic natural duck nesting behaviour.

Day twenty-five — Lockdown. Stop turning. Increase humidity to 65–70%.

Day twenty-eight — Hatch day. Ducklings typically take longer to hatch than chicks — twenty-four to forty-eight hours from first pip to full emergence is not uncommon. Patience is essential. Do not open the incubator during the hatch — the humidity loss can shrink-wrap unhatched ducklings in their shells.

Candling — Monitoring Development

Candling is the process of shining a bright, focused light through the egg to observe the developing embryo inside. It allows you to identify infertile eggs (clear, no development), early deaths (a blood ring with no embryo growth), and healthy development (visible embryo, blood vessels, growing air cell).

Equipment. A purpose-made egg candler provides a focused, bright LED light. A powerful torch held against the shell in a dark room also works. Some incubators include a built-in candling light.

When to candle. Day seven (first check — remove infertile and failed eggs). Day fourteen (progress check). Day eighteen (pre-lockdown check — the egg should be almost entirely dark with a clearly defined air cell).

Minimise handling. Candle quickly and return eggs to the incubator within five to ten minutes. Do not candle all eggs at once — work in small batches to minimise temperature disruption.

Lockdown — The Final Days

Lockdown is the critical final phase. From day eighteen (chickens) or day twenty-five (ducks), the incubator should not be opened.

Stop turning. The chick needs to orient itself into the correct hatching position.

Increase humidity to 65–70%. Fill all water channels. The higher humidity prevents the shell membrane from drying out and trapping the chick.

Do not open the incubator. Every time the lid is opened, humidity drops instantly and takes significant time to recover. Dipping humidity during lockdown is one of the most common causes of chicks becoming stuck in the shell (shrink-wrapping). Observe through the viewing window only.

Hatch Day — What to Expect

Pipping — the chick breaks through the shell with its egg tooth (a small, hard protrusion on the beak). You may hear peeping from inside the egg before the pip appears.

Zipping — the chick rotates inside the shell, cracking a line around the circumference. This can take hours.

Emergence — the chick pushes free of the shell. It will be wet, exhausted, and unsteady. This is normal.

Leave the chick in the incubator until dry and fluffy — typically six to twelve hours. Do not remove wet chicks to the brooder; they need the warmth and humidity of the incubator to dry.

Do not assist the hatch unless you are experienced and have confirmed that the chick has been stuck for twelve or more hours with no progress. Premature intervention tears blood vessels still connected to the shell and can cause fatal bleeding. The urge to help is strong — resist it unless genuinely necessary.

Brooder Setup — Ready Before the Hatch

The brooder must be set up and running at the correct temperature before the first chick hatches. You do not want to be assembling a brooder while chicks are drying in the incubator.

Brooder essentials. A container (plastic tub, cardboard box with high sides, or purpose-built brooder) with a secure lid or cover to retain heat and prevent escape. A heat source — a brooder heat plate (the modern standard — chicks huddle beneath it as they would under a hen) or a heat lamp (effective but carries fire risk — secure the lamp with a clamp and chain, never just a clip). Non-slip flooring for the first few days (paper towels over newspaper — smooth surfaces cause splayed legs in newly hatched chicks). Chick starter feed and a shallow chick drinker.

Temperature. The brooder should be approximately 35°C (95°F) at floor level for the first week. Reduce by approximately 3°C (5°F) per week until the chicks are feathered and able to regulate their own temperature (typically five to six weeks).

The chick behaviour test. If chicks huddle directly under the heat source and peep loudly, they are too cold — lower the heat plate or bring the lamp closer. If they scatter to the edges of the brooder, panting, they are too hot — raise the heat source. If they are spread comfortably across the brooder, occasionally visiting the heat source, the temperature is correct.

The First Forty-Eight Hours

Water first. When chicks are moved from the incubator to the brooder, gently dip each beak into the water to teach them where it is. Chicks dehydrate quickly. Electrolyte supplements can be added to the water for the first few days to support recovery from the hatching effort.

Feed. Provide chick starter crumbles (see our guide to poultry feed) from the moment chicks are in the brooder. Newly hatched chicks absorb the remaining egg yolk internally, which sustains them for up to seventy-two hours — but offering feed immediately encourages eating behaviour and ensures the weaker chicks are not left behind.

Observation. Watch for pasty butt — droppings that stick to the vent area and harden, blocking further elimination. This is common in the first few days and can be fatal if not addressed. Gently clean the vent area with warm water and a soft cloth if you observe this.

Ducklings follow the same brooder principles but are messier with water (they will attempt to swim in any available water source). Use a drinker designed to prevent immersion — ducklings can drown in open water dishes before their down is waterproofed.

Incubation Capacity — Matching Incubator to Ambition

Incubators range from small tabletop units holding seven to twelve eggs to cabinet incubators holding hundreds. For most backyard and smallholding keepers, a unit holding twelve to forty-eight eggs provides a practical capacity for one or two hatches per season.

Smaller units (seven to twelve eggs) are ideal for educational hatching, first-time incubation, or small-scale replacement flock hatching. They are affordable and take minimal space.

Medium units (twenty to forty-eight eggs) suit established keepers who want a meaningful number of chicks per hatch for flock replacement or a small breeding programme.

Cabinet incubators (one hundred or more eggs) are for serious breeders and small-scale commercial hatching. They offer the most precise temperature and humidity control but at significantly higher cost and space requirements.

Comparing Incubator Types at a Glance

Common Incubation Mistakes

Not stabilising the incubator before adding eggs. Run it empty for twenty-four hours first. Temperature and humidity must be stable before eggs go in.

Opening the incubator too often. Every opening loses heat and humidity. Candle quickly. Do not open during lockdown.

Incorrect temperature. Verify with an independent thermometer at egg level. Do not trust the built-in display without verification.

Incorrect humidity — particularly during lockdown. Low humidity during the final days shrink-wraps chicks in their shells. This is one of the most common causes of failed hatches.

Forgetting to stop turning before lockdown. Eggs must not be turned during the final three days. If your incubator has an automatic turner, remove it or switch it off.

Helping chicks hatch too early. The blood vessels connecting the chick to the shell must dry and retract before the chick emerges. Premature intervention causes bleeding and death.

Not having the brooder ready. Set up the brooder before the hatch, not during it.

Pre-Purchase Checklist

• [ ] Does the incubator have automatic egg turning?
• [ ] Is it forced-air (internal fan) for consistent temperature?
• [ ] Does it have accurate temperature control (digital display, ±0.5°C or better)?
• [ ] Does it include humidity monitoring and easy water access?
• [ ] Is the viewing window clear enough to observe without opening?
• [ ] Does it have a built-in or compatible egg candler?
• [ ] Is the capacity appropriate for my planned hatch size?
• [ ] Do I have an independent thermometer and hygrometer for verification?
• [ ] Is my brooder set up and tested before hatch day?
• [ ] Have I sourced fertile eggs from a reliable supplier?
• [ ] Do I have a plan for cockerels?

Why Buying Through Amazon Makes Sense

Incubator reviews from other hatchers — describing real-world temperature accuracy, humidity reliability, hatch rates achieved, and whether the automatic turner actually works consistently over a full twenty-one-day cycle — are the most valuable purchasing information available. Reviews describing specific hatch experiences (species, hatch rate, problems encountered) provide practical insight that specifications alone cannot.

Amazon Marketplace Protections

Amazon purchases are covered by the A-to-Z Guarantee. In the UK, the Consumer Rights Act provides additional protection. In the US, equivalent protections apply.

Amazon Renewed may include incubators at reduced cost — electronic equipment with cosmetic wear functions identically to new.

Related Guides

• The Complete Guide to Chicken Coops and Housing
• The Complete Guide to Poultry Feed and Supplements
• The Complete Guide to Smallholding Essentials

The first time you hear peeping from inside an egg you set three weeks ago, you will understand why people have been hatching birds for thousands of years. Some experiences do not lose their wonder with repetition — and this is one of them.