Why Eggs Don’t Hatch (and How to Fix It)

Problems with the eggs

1. Infertile eggs. Too few roosters, old or overweight roosters, or poor breeder nutrition. Aim for roughly one active rooster to every 8–10 hens and candle on day 7 to measure fertility.
2. Old eggs. Hatchability drops after about 7 days of storage. Set eggs as fresh as possible.
3. Poor storage. Store eggs somewhere cool (not in the fridge), pointed end down, and let them reach room temperature before setting.
4. Dirty or cracked eggs. Bacteria enter through cracks and dirty shells. Set only clean, sound eggs.

Problems in the incubator

5. Temperature too high. Early hatch, weak or deformed chicks. Check against a second thermometer.
6. Temperature too low. Late, drawn-out hatch and chicks dying at pipping.
7. Humidity too high. Large, sticky chicks that drown or cannot turn to pip.
8. Humidity too low. Chicks stuck to dry membranes (“shrink-wrapped”).
9. Turning stopped or opening during lockdown. Turning too little early on and opening the lid late in the hatch both reduce hatch rate.
10. Power failures. Long outages, especially in the last week, kill embryos. See hatching during load shedding.

Reading the clues

After a poor hatch, open the unhatched eggs (outdoors, with gloves). Clear eggs point to fertility or storage; early deaths (blood rings) to storage, temperature or handling; fully formed chicks that did not pip to humidity or temperature at the end. Keep notes for every batch so you can spot patterns. Our temperature and humidity guide has the right settings for each egg type.