Chicken egg incubator lockdown: what it is, why it's critical for a successful hatch, and how to do it in 5 simple steps .

If you're incubating chicken eggs you'll probably have heard the words "incubator lockdown". But what exactly is it, and what needs to be done?

Egg incubator lockdown: what to do and how to do it. Pin for later.

Firstly: What does "lockdown" mean?

"Lockdown" in this context is simply the word used to describe the time when an egg incubator has its settings optimised ready for hatch. 

The eggs are not turned or candled again and the incubator is left with its lid closed until after the chicks have hatched.

It requires five main things to be done.

When should incubator lockdown take place?

The optimum time is three days before the eggs are due to hatchFor normal sized chicken eggs this is at Day 18 of incubation.

Bantam eggs tend to hatch earlier, at around 19 days into incubation. So they should be locked down at day 16.

If you have one incubator holding both large and bantam chicken eggs and you don’t have a way of separating them, lock down all the eggs at Day 16.

5 straightforward steps to locking down your incubator.

There are just five simple things to be done on day 18 to lock down any chicken egg incubator and make sure you have the best possible chance of healthy chicks hatching.

Incubator lockdown to do list.

Please note: I’m using my original Brinsea Mini Advance and Octagon 20 incubators as examples in these instructions, but exactly the same principles apply whichever incubator you’re using.

5 critical steps to incubator lockdown.

If you want to jump to a particular section, use these links. However, all the steps are critically important for a successful hatch, so if you're unsure of anything please do not skip!

Chicken egg incubator lockdown: a video.

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Chicken egg incubator lockdown, step 1: stop chicks from slipping.

You need to prepare a non-slip surface in the incubator for the baby chicks when they hatch.


Chicks will start to move around immediately. They stumble around the incubator, into and over other eggs, into and over each other. 

A slippery surface can cause their weak, spindly little legs to do the 'splits', resulting in a condition known as 'splayed leg' – or even a completely dislocated leg.

A dislocated leg would mean the chick has to be culled. Splayed leg can be fixed, but it’s better to prevent it from happening in the first place – and saves the chick from a potentially very painful injury.

Some incubator companies, including Brinsea, now include a base with their package.

If not, choose a non-slippery surface like this one. It's a plasticised material usually used for shelf lining. This is the one I use ('antiscivolo' meaning anti-slip – for those who don't know, I live in Italy!).

Non slip matting for the floor of the incubator.

How to make an incubator anti-slip base.

  • Take your eggs out of the incubator and put them somewhere safe. They’ll be fine for a few minutes. I use a towel or blanket on my incubation table to cushion them.
  • Now remove the turning plate or egg tray. In the case of this incubator it's the yellow disc with the holes where the eggs have been.
Preparing eggs for lockdown of the incubator

Put the disc or egg tray on top of the plastic and draw around its circumference with a pen.  Now cut out to the shape of the tray, making it slightly smaller than the tray itself.

Preparing an incubator for lockdown by making a non-slip base.

For Brinsea's small incubators, fold the material into quarters and cut out a hole in the middle to allow for the water pot.

Preparing a non slip base for an incubator hatch.

That’s it! You should now have a chick-slip-proof mat to keep your chicks safe when they hatch.

A home made non slip base for chickens to hatch safely.

I make exactly the same type of base for chicks hatching in my Brinsea Octagon 20 incubator.

Hatching can be a messy process, so once all the eggs have hatched it's wise to discard this base and make a fresh one next time you incubate. 

Incubator lockdown step 2: egg candling at day 18.

  • If you haven't yet got a candler, look at this page where I review the best candling devices on today's market.
  • Before you put your eggs back into the incubator, candle each of them in turn.
  • Eggs which have shown no signs of development should be removed at this point. This is an example of an egg which is clearly not going to develop.
A non fertile egg showing no signs of development.
  • Eggs with cracks, particularly if they also have 'gunk' on the shell – a kind of sticky oozing liquid – should also be discarded. These eggs have stopped developing. If left, they will explode, scattering bacteria over the rest of the hatch.
  • Eggs with a "blood ring" should also be discarded.

A blood ring is a sign that the embryo has died and the blood, which in a healthy hatching egg is spread by a complex system of veins, has collected in one place.

This is an example of what to look for in this type of egg.

A typical blood ring in an incubated egg.  This egg should be discarded.

For more information, including an explainer video looking at a blood ring and what's inside the egg, see this page.

While you're candling, mark the air cell.

You will hopefully have been doing this throughout incubation as you candle your eggs, but it’s important especially to do it at lockdown (day 18 – day 16 for bantam eggs). 


The air cell  is where the chick should begin to break through the shell. It won’t be exact, because the air cell will continue to grow over the next three days before hatching. But it gives a reasonable picture.

If your chick begins to 'pip' elsewhere, it may need some help.

The first 'pip'.The first 'pip', very close to the air cell when last candled.

Once you've discarded non developing eggs and marked air cells in the developed set ...

  • Eggs which are showing 'normal' development for Day 18 – i.e. most of the egg is dark, with a growing air cell – can now be put back into the incubator. 
  • Do not place the turning disc back into the incubator. The eggs should be placed on their side, lying on your non-slip base.
  • For incubators like the Octagon 20, which holds eggs standing on end during incubation, this is the time to lay them flat. I can generally fit around 20 - 22 standard sized chicken eggs in this way – though it does get very crowded once they start to hatch!
Lie the eggs flat for hatching.My Octagon 20 incubator at lockdown.

Chicken egg incubator lockdown, step 3: increase humidity.

Humidity in the incubator for hatch needs to be higher than for incubation, so at lockdown we need to adjust it accordingly

The membrane which surrounds the chick must be kept moist enough for the chick to be able to peck through. If it’s too dry, the chick will get stuck and won’t be able to hatch. Too wet and the chick will drown.

If you are using a humidity pump with an incubator like the Octagon 20, the percentage should be increased now, until the digital readout reaches 65%.

The Octagon 20 incubator readout at lockdown.

If you’re using an incubator like the Mini Advance which has neither a humidity pump nor a percentage readout, you need to rely on the manufacturer’s instructions – or buy an inexpensive hygrometer

I use this anyway, as a double check that humidity levels are as close to ideal as possible.

In the case of the Mini Advance (or any of Brinsea’s small incubators) both chambers of the water pot in the centre of the incubator should be filled at lockdown and kept filled right through hatching. 

Make sure you put the guard on the top of the pot. Newly hatched chicks can easily fall into it and drown.

The Brinsea Mini Advance at lockdown - fill both water pots.

Incubator temperature for the last 3 days of incubation.

The temperature of the chicken incubator from day 18 should remain exactly as it has been for the entire time: 37.5ºC, 99.5ºF.

Remember: it will drop when you open the incubator, so avoid doing that unless absolutely necessary.

Managing ventilation at lockdown.

Once chicks get to this advanced stage they need a much higher supply of oxygen than they have before now. Poor ventilation can lead to chicks dying, even at this late point.

Make sure, whichever incubator you’re using, that it’s standing in a place with a good supply of air. Don't keep it shut in a cupboard, for example. 

Smaller incubators with a fan, like the Mini Advance, will take care of ventilation for you so there’s no need to worry.

If you’re using an incubator with an air vent (the Octagon 20, for example), open it to at least halfway at lockdown. 

The Octagon 20's air vent needs to be adjusted for lockdown.

You may need to increase moisture levels to keep humidity at the right point. before I had the humidity pump to take care of this for me (what a lifesaver!) I used wet kitchen towel when necessary.

Simply scrunch a piece of kitchen paper and dampen it with warm water. Not cold, because that will reduce the incubator's temperature.

Put it into the incubator until the humidity has increased, then remove it. Leaving it in will make the humidity level too high.

Egg incubator lockdown step 4: stop turning the eggs.

The chicks now need a bit of peace and quiet to get themselves into the right position for hatching.

So you should stop turning the eggs now.

If you’re using the Mini Advance, the incubator will automatically know when this should happen and will stop turning for you. All you need to do is remove the turning disc and substitute your plastic flooring.

The Brinsea Mini Advance stops turning the eggs automatically.

If you have an incubator like the Brinsea Octagon Advance which uses a turning cradle, simply lift the incubator off the cradle and place it on a flat surface. 

You can now unplug the cradle, clean it and put it away for next time.

In an incubator which has an automatic turner but doesn't count the days, such as the Brinsea Maxi 2 Advance EX, re-set the digital indicator to not turn.

This is absolutely critical. Moving the eggs from now on will mean the chick doesn't position herself properly for hatch, and can lead to her either dying in the egg, or trying to hatch and becoming stuck.

Egg incubator lockdown step 5: close the lid and leave it alone!

From now until hatching, your incubator lid should be opened as little as possible and the eggs should not be moved, touched or candled again.

It’s important that humidity levels are maintained inside the incubator throughout lockdown and hatch so that the chick does not get “shrink-wrapped”. This happens when the membrane dries out and literally shrinks around the chick. The chick can’t move and so can’t hatch.

Opening the lid will drop humidity levels massively, which is why it needs to be avoided as much as possible from now on.

If your incubator has an air vent , it will help to control humidity without disturbing the eggs. 

  • To increase humidity, close the vent to the three-quarters point. Do not close it completely – the chicks need oxygen from this point onwards.
  • To decrease humidity, open the vent fully as in the picture below. Wait until humidity has stabilised and then close the slider to the halfway point.
Brinsea's Octagon 20 incubator, all set for use.

What about keeping water pots topped up during lockdown?

When I first needed to do this after lockdown I was terrified, because all the advice is not to open the incubator at all after day 18. 

But how to fill the water chambers if we can’t lift the lid?

I’ve since learned to relax. Opening the lid occasionally for a few seconds to fill the pot won’t affect humidity much. The levels will rise again, although that can take a while.

One word of warning though: do avoid opening the lid if any egg has started to ‘pip’ – that is if you can see even a tiny hole or crack. 

A drop in humidity at that point can be fatal, because the internal membrane can dry out in seconds. As it does so, it wraps the chicken too tightly for it to move.

A chick pipping at Day 21 of incubation.If you see even a tiny hole, do not open the incubator until the chicks have hatched.

And that is all there is to your chicken egg incubator lockdown process!

Are you planning to incubate some eggs?

These links will take you to pages which are designed specially to help you through the process. The first page also contains a link to my free, 28-day, step-by-step hatching series – you're very welcome to join in if you're a member of my Chicken Digest newsletter community.

Click on any of these pictures to go to the page.

The amazing hatching chicken eggs section - link.
Everything you need to know about choosing the right incubator for your needs. Click to view article.
How to candle chicken eggs - link.
Incubating and hatching your own chicks - book review - link.
Got new chicks and not sure how to care for them? Here's all you need to know!
What do baby chicks eat? Link.
What treats can chicks eat? - link
Tell the story of your chicks, here! Link.
Raising chickens - month by month tasks - link.
Link to Raising Happy Chickens home page.