Build a Homemade Incubator

Learn how to save money by building a small egg hatchery. Important details include egg-temperature and humidity control.

| March/April 1982


A homemade incubator helps the small-scale poultry farmer save money.


Most folks who keep small flocks of fowl (whether for eggs or meat or both) likely have — at one time or another — considered buying an incubator. The freedom that the devices offer (in maintaining a controlled breeding program and in exchanging less productive hens for better layers) can be a real boon to a farmstead bird operation. Unfortunately, you can purchase quite a few commercially hatched day-old chicks for the price of one quality incubator because a store bought apparatus can run from about $150 up (and I mean way up!).

Now it's true that an effective homestead hatchery has to be able to accomplish several jobs at the same time, and that it must do some of them very accurately, but don't let those concerns discourage you from building your own incubator. Once you match the necessary tasks with the various mechanical systems that can handle the chores, the contraption will begin to seem a whole lot less intimidating.

Maintaining a Constant Incubator Temperature

In order to hatch a good percentage of fertile eggs, an incubator must be able to maintain a constant temperature. Though different sorts of eggs require different heat levels, most will grow and hatch well at 99 to 101 degrees Fahrenheit. When incubating chickens and quail, I aim for a steady 99-3/4 degrees Fahrenheit . . . though the actual temperature may well fluctuate by as much as half a degree. Sure, that does sound imposingly precise, but such accuracy isn't all that difficult to achieve.

Because even 1 degree Fahrenheit of inaccuracy in a thermometer could make a vital difference in the percentage of the hatch, it's a good idea to use three or four instruments and to average their readings. One quarter turn on the thermostat adjustment screw will produce about a 1 degree Fahrenheit change inside the incubator, so it is possible to home in pretty close to the right level of warmth. (Of course, you'll want to experiment a bit with the various controls before trying the heating system out on your first batch of eggs.)

Monitoring the Humidity

If it's either too dry or too humid inside the incubator, the chicks will suffer. The humidity, measured with a wet-bulb thermometer, will ideally start at 85 degrees Fahrenheit and then rise toward 90 degrees Fahrenheit during the last few days of the incubation period. Low air moisture levels can cause the chicks to stick to their shells, and excessive dampness sometimes produces swelling. (It's important to remember that eggs are permeable and that water, and other substances as well, can get into the shell.)

A sponge, sitting in an 8-by-8-inch bread pan filled with water, adds moisture to the incubator. Of course, the dimensions of the sponge will depend on just what the relative humidity is to start with, and you'll be able to get it right only after a bit of experimentation. I've found that a 1-1/2-inch-thick, 4-by-8-inch sponge suits both extremes of our western North Carolina climate, which is typically humid in the summer and relatively dry in the winter. Again, try out different sponges and keep careful track of humidity variation on the hygrometer (remember to use a wet-bulb thermometer with light cloth).

1/12/2015 12:00:03 PM

Not to bright- you would never hatch any eggs. The "proper" temperature (all the time during the incubation period is 99 1/2 degrees!

aj shackleford
3/12/2013 11:57:52 PM

I agree with, shirley_24, I tnought he was going to tell me how to build an incubator, but there was nothing about that. Disappointed.

4/2/2009 10:33:50 PM

I am very disappointed to find absolutly NOYHING about building an incubator on this page about doing so!?!?!?!?!?

2/5/2008 5:47:08 PM

Sir,I'm interested to build my own egg incubator.Kindly give me detailed name&address whom i can order Dayton egg turner complete assembly i.e.motor plus control system.Thank very much & your input would be highly appreciated.Haban

3/25/2007 5:13:31 PM

Can your incubator be a little bit higher in temperature to still hatch the eggs???

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