7 Reasons Your Eggs Aren’t Hatching (And How to Fix Each One)
A failed hatch is almost never bad luck. These are the most common causes — from humidity swings to skipped turning — and exactly how to fix each one.
A failed hatch feels like bad luck. It almost never is.
Most incubator failures trace back to one of a small, fixable set of mistakes — not a bad batch of eggs. Here’s what actually derails a hatch, and exactly how to fix each cause before your next batch goes in.
1. Humidity Was Off During Lockdown
The last three days before hatching (“lockdown”) are the most humidity-sensitive window of the entire process. Chicken eggs generally need 45–50% humidity through days 1–18, then a jump to 65–70% for days 19–21. Too low during lockdown and the inner membrane dries out and shrink-wraps the chick before it can turn and pip. Too high the whole way through and chicks can drown inside the shell.
Fix: Track humidity daily, not just at a glance. An incubator with auto-refill water ports and a live digital readout removes the guesswork — you’re not estimating from how damp the sponge feels.
2. The Eggs Weren’t Turned Enough
Eggs need turning 3–5 times a day for the first 18 days so the embryo doesn’t stick to the shell membrane on one side. Manual turning is the single easiest step to forget, especially on day 3 or 4 when nothing visibly looks different yet.
Fix: An automatic turner that runs on a set schedule (and stops itself before lockdown) removes the one task most hatches actually fail on.
3. Temperature Fluctuated More Than It Looked Like
Chicken eggs need a steady 99.5°F (37.5°C). A swing of even 2–3 degrees for several hours can slow or stall development — and a cheap analog thermometer can be off by that much without you knowing.
Fix: Use a digital sensor, not a dial thermometer, and keep the incubator away from direct sun, drafts, or vents that cause temperature swings room-to-room.
4. The Eggs Were Infertile or Too Old Before Incubation Started
Not every “failed” hatch is an incubator problem. Eggs stored more than 7–10 days before incubation, stored cold, or simply infertile to begin with won’t develop no matter how well you run the incubator.
Fix: Candle around day 7–10. A clear, veiny network means development is underway; a clear, empty-looking egg almost certainly means it was never fertile or was stored too long.
5. The Incubator Was Opened Too Often
Every time the lid comes off, temperature and humidity drop and take time to recover. Checking on eggs multiple times a day — especially during lockdown — is one of the most common self-inflicted causes of a failed hatch.
Fix: A built-in candler and a clear viewing dome let you check progress without lifting the lid at all.
6. Poor Air Circulation Inside the Incubator
Eggs need fresh airflow to get oxygen and release CO2 as the embryo develops. An incubator without real air circulation creates uneven pockets — some eggs do fine, others next to them don’t.
Fix: Look for dual circulating vents, and avoid overcrowding trays past the incubator’s rated capacity.
7. The Eggs Came From Stressed or Unhealthy Parent Stock
This one has nothing to do with your incubator. Hens under heat stress, poor nutrition, or illness lay eggs with lower fertility and weaker embryos, regardless of how well they’re incubated afterward.
Fix: If you’re sourcing eggs rather than collecting your own, ask about the flock’s health and diet before you buy.
What Actually Makes a Hatch Succeed
A good hatch rate isn’t luck — it’s consistency. Steady temperature, steady humidity, regular turning, and minimal disturbance, held for 21 straight days without a gap.
At Mainpaws, our egg incubators are built around exactly that: automatic turning, a dual auto-refill humidity system, and a built-in candler so you can check progress without ever breaking the environment you’ve dialed in.
Frequently Asked Questions
How do I know if humidity was actually the problem?
Check the air cell at candling (day 7–10) and again near lockdown. A too-small air cell usually points to humidity that ran too high; an oversized, fast-growing air cell points to humidity that ran too low.
Can I still hatch eggs after a power outage?
Often yes, if it’s brief. Eggs can survive a few hours below temperature, especially past the first week. Don’t open the incubator to check — restore power and give it the full 21 days before giving up.
Is it normal to lose some eggs even when everything goes right?
Yes. Even under ideal conditions, hatch rates of 75–85% are considered strong for home incubation. Not every fertile egg hatches, and that’s not a sign you did something wrong.
How often should I candle my eggs?
Twice is usually enough — once around day 7–10 to confirm development, and once around day 18 before lockdown to remove any clearly non-developing eggs.
What’s the single biggest cause of failed hatches?
Inconsistent humidity during lockdown, by a wide margin. More hatches are lost to a dry or overly wet final three days than to any other single cause.
