Quail eggs are among the fastest to hatch: 17 to 18 days are enough for Japanese quail (Coturnix), the most commonly kept. It's a great species to start incubation with, as long as you handle a few details specific to small eggs.
Quail incubation duration
Allow 17 to 18 days for Japanese quail (Coturnix coturnix japonica) at 37.5 °C. Button quail (Chinese painted quail) take about 16 days, and some ornamental quail a little longer. A well-run batch usually hatches over 24 to 36 hours.
Day-by-day calendar
Set on day 1 at 37.5 °C, humidity 45 to 55%. First candling around day 7 to spot blood vessels and remove clear eggs. Lockdown on day 14: stop turning and raise humidity to 65 to 70%. Hatching is expected between day 17 and day 18.
What's special about quail eggs
Small and fragile, quail eggs need careful handling and are often placed in dedicated trays. Their speckled shell makes candling harder, so use a strong light in a dark room. As with chickens, turn at least twice a day, ideally three times, until lockdown.
Common mistakes with quail
Humidity that is too low is the most common mistake, because small eggs lose moisture faster. Too much humidity, on the other hand, stops the air cell from forming. Also avoid opening the incubator during lockdown: quail chicks are tiny and dry out very quickly.