The Dry Incubation Method for Hatching Difficult-to-Hatch Breeds

~ By Karen

I hatch a LOT of eggs – generally more than a thousand annually. Over the years I have had a great deal of luck with the Dry Incubation Method. I hatch a lot of Swedish Flower Hen eggs, and for whatever reason, this breed can be very difficult to hatch in an incubator – but even shipped Swedish Flower eggs seem to do well using this method.

Circulated Air:
If you don’t have a circulated air incubator, for best hatching results it is best to add a fan. Measure the spacing between the holes in the top where a fan would go, and get a computer fan that is about that size. Wire it with an old cell phone charger that's rated for 5-9 volts. (Computer fans are generally 12v, but the lower voltage means it won't spin at top speed, so your eggs/chicks don't have to hatch in hurricane conditions). 

Fans can blow up or down. Make sure yours is blowing UP. (Circulated air goes out to the sides rather than straight down - usually there are arrows on the side of the fan showing direction it blows).

Auto-Turner:

If you don't have one, add an auto turner, or be prepared to be VERY diligent about turning your eggs regularly. Hand-turning can be problematic as it will cause temperature changes when ever you open your incubator.

Preparing Your Incubator:

It is a good idea to wrap the cheaper, Styrofoam-type incubators in some sort of insulating material. A blanket will work, or a box lined with insulation. These incubators can be sensitive to temperature changes in the room they are in, so if it is possible, set them up in an interior room where there is no direct sunlight. If your house temperature changes throughout the day in the winter, it is a good idea to set up a small, temperature-sensitive heater to try to keep your incubator room at a steady temperature.

Get your incubator set to the proper temperature at least 3 days before setting your eggs. Use a digital, human grade thermometer for best results. If you wish to use a good quality digital thermometer that will stay inside the incubator, be sure to get TWO. Thermometers can be off a bit and if you notice a variance between your two thermometers, get a third to be sure.

Pull all the vent plugs out of your incubator – you won’t be using them for this hatch. Set the temperature where you think it will be right, and leave it alone for 24 hours. If you are using a digital thermometer made for taking human body temperature, wrap it in whatever you have on hand (fabric, toilet paper, whatever) to allow the thermometer to fit in the hole and sit there comfortably, with the hole plugged by the wrapping material. Put the bulb of the thermometer anywhere from the bottom of the fan to about where the middle of an egg would be to get the most accurate reading. (With circulated air, the temperature should be pretty close to the same throughout the incubator, but that's a good area to test. Be sure the thermometer(s) are far enough from a heating element to prevent incorrect readings when testing the temps.)

The cheap digital thermometers you can get anywhere are just that. They’re cheap and can be unreliable.  A lab grade thermometer can be verified/calibrated two ways (and we recommend using both). First, put it in a cup of ice water, stirring the water constantly. It should read 0 C or 32 F.  Second, put it in a pot of water and bring it to a boil, again stirring constantly so the water doesn't get hot spots. It should boil at 100C or 212F.

Whatever thermometer you have, learn how it works and how long it's recording cycle (if digital) is. Be aware if it only goes up to the high stable temp or if it shows variable temps, etc.  Then put it in the incubator (thru the vent hole so you can read it easily) and start watching it.  Write down the temp it's reading (once it's been in there maybe 10 minutes) when the heating element comes on. Time the heat cycle (doesn't have to be exact but helps to know how long it's cycling) and take another reading when the element goes back off. Again, time how long the element is off...  ideally it should be on for a shorter time than it's off.  Figure out, over 5 or 6 cycles, if your incubator temperature stays pretty consistent.  the highest and lowest temps you record will actually be AFTER the heating element turns off and on, since it's got enough thermal mass to continue heating slightly even after it turns off, and the coolest will be after the thermostat turns it back on, again because it takes a second to start building up more heat... 

Taking a number of readings will tell you roughly what the temp range will be.  If it's high or low overall from 99.5 (average temp) then you need to adjust the incubator. (A LITTLE AT A TIME!)  Don’t do more than a quarter turn on the adjuster at a time, and not more than once every 5 or 6 hours at least. 

Once you've got it set well, use the lock nut (a second wing nut at the bottom of the stem against the incubator) to lock it down so it doesn't turn accidentally. Then test your temps again, in case you moved it. (Not all incubators have this locking feature.) Run it for a good 24-48 hours and just check periodically to make sure it's in the right range each time.

Setting Your Eggs:
Once you've got your eggs, set them in the egg turner (which should have been in there while you were setting the temps btw) with the turner turned off for a day or two to allow the eggs to settle a bit (only for shipped eggs, but won't hurt local either). Plug the turner in on day 3. On day 18-19 (I usually do day 19, myself) move the eggs to a paper/cardboard egg crate (lid removed), take out the turner and lay some paper towels (not industrial stuff but the kind you use at home LOL) on the floor of the incubator and put the egg crate in, roughly near the middle of the incubator.

Humidity:
As far as humidity, any old digital hygrometer will work fine, since you really just need an estimate on that in my opinion -  for the first 18-19 days, add NO water. Easy enough. Make note of what the humidity reads, though. Usually the incubator will read anywhere from 15-30% during incubation, and that's just fine. After lockdown, increase the humidity to anywhere from 45-60%, again depending where it was reading before.  What I do is use a disposable plastic container (for food storage), usually the 2-3 cup size, roughly 4x6" rectangle about 2-3" deep. I used some scrap hardware cloth (1/2" mesh) and made a cover for it so chicks wouldn't fall in accidentally, and just filled it up with hot water. Once you notice a pip, again using hot water, quickly open your incubator and fill an empty slot in the egg carton with water. Then leave it all alone until either your hatch is done or more than 24 hours have gone by from the first chick out. If your eggs haven't all hatched after 24 hours, add some more water to the egg crate and leave it alone for another 12-24 hours.

Candling:
Oh - and candling...  I candle all the eggs while they're in the incubator, with the lights in the room off so I can see as much as possible. I candle around 7-10 days and pull any eggs that have no obvious development.  I only candle once more, when I’m moving the eggs over to the egg crates and remove any obvious quitters at that point also.

So there you have it! Good luck and happy hatching!

~ Karen