turning eggs

There are many different conditions that must be met in order to properly incubate chicken eggs and bird eggs in general. What nature does effortlessly through instinct we must replicate through machinery. This replication is often clumsy and imperfect, but technology has taken great strides toward more efficiently copying nature. Most of the incubators manufactured and sold by Brinsea Products feature automatic turning, but if you find yourself incubating without this feature, it is imperative that you manually turn your eggs. What happens if you don’t turn the eggs in an incubator?

Why Turn Eggs?

Hens regularly turn their eggs, so it is important that we copy this habit in an electric incubator. But why? What will happen if we don’t? The first thing we need to look at is how eggs develop during incubation. Throughout the process the embryo grows into a baby chick, where improper temperature or humidity can spell disaster. 

As the embryo forms on the yolk, the yolk becomes lighter and lighter. This causes it to float upward in the egg. The yolk is somewhat held in place in the center of the albumen by the chalaza, but this twisted membrane -- which serves as the rotating axis to keep the embryo on top of the yolk -- only connects the yolk to the ends of the egg, not the sides. So, the yolk continues moving upward (toward the side that is on top, which in nature would be closest to the heat of the hen’s body).

If not turned for long periods the yolk will eventually touch the inner shell membranes. When the embryo touches the shell membranes, it will stick to the shell and die. Regularly turning the egg will prevent this, and ensure healthy embryo development.

Another key benefit to turning your eggs is that by doing so, you are allowing the embryo to encounter fresh nutrients and oxygen inside the egg. Turning also moves metabolic wastes way from the embryo. This is especially important during the first week of incubation.

Something that might seem obvious to an experienced hatcher but that may not be obvious to someone just dipping their toes into incubating, is which way to turn the eggs. When you place eggs in an incubator, we recommend that they are placed on their sides, which is the way we see them in nature. The exception to this is commercial hatcheries that place eggs upright (with the pointed end down) so as to maximize space. So, when we mention turning, we are talking about turning from side to side, not end over end.

Types of Turning

How often an egg should be turned depends on the type of bird you are hatching. How far the egg should be turned depends on this as well. Chicken eggs (and other fowl) are best turned every hour or so. They should be turned 80 degrees each time, so it is important to pay attention to the settings on your incubator if you are using automatic turning. Parrot eggs need to be turned farther and much more often. A good rule of thumb for parrots is 180 degrees a few times an hour.

If you are not using an automatic turner, then it may be a good idea to mark on your eggs where they should be turned. You can draw marks on each space on the side of the egg where it should be turned to help you keep track, or even a numbered sequence for more accurate reference.

When choosing an incubator with automatic turning, it is important to consider the turning method. Some incubators come fitted with tilting trays that turn the eggs from one side to another throughout the day. These are typically reserved for commercial use, and are generally only used with poultry. This turning method is straying a little from the natural way birds turn their eggs, so non-domesticated birds, like parrots, should not be hatched with this method.

Another turning method is with troughs or channels. These are similar to tilting trays, but instead they tilt the eggs in semicircular troughs. The eggs are lined up in the rows and rotated back and forth, much like the tilt trays.

The final automatic turning method that we will mention is the moving floor. Some incubators have a round base where the eggs sit, which allows the floor to rotate to turn the eggs. Eggs that are regular in shape work well with this method. A similar method is with rollers that the eggs sit on. These rollers are turned by the floor moving underneath them, which then turns the egg. Moving floors allow for larger angles of turn than tilting trays or troughs and have proven particularly beneficial to non-domesticated exotic species. Specialized incubators like those from Grumbach and Inca, or Brinsea’s Contaq and Zoologica models use rollers.


It is not uncommon for some eggs not to hatch during incubation, but troubleshooting what may have caused the problem can help you avoid the same issues in the future. Some of the most common issues we see that are related to turning include:

  • Early death: Insufficient turning can cause embryo death between days 3 and 6 of the incubation period for chickens.
  • Mid-term death: Improper turning can cause embryo death between days 7 and 17, although this is less common.
  • Failure to pip: Inadequate turning results in decreased development and poor nutrient absorption, which can cause a fully-developed embryo to fail to pip.
  • Dead in shell: If an embryo pips but then fails to hatch, this can be caused by inadequate turning for the first 12 days of incubation, for reasons listed above.

Of course, these issues can be encountered due to a variety of other reasons, and just because your embryo fails to pip or experiences an early death does not mean turning was necessarily the issue. However, it is important to examine every aspect of the incubation process to help improve your method and ensure high hatch rates.

An Important Note on Turning

It is important to note that for both automatic and manual turning, the egg must not be turned in the same direction every time. If this occurs, the chalaza will wind up and eventually break, which causes embryo death. If you choose to manually turn your eggs, alternate turning direction in order to avoid this. If you choose an incubator with an automatic turning feature, make sure it turns the eggs in a random or alternate direction each time. Some incubators do not ensure this feature with their automatic turning, so that is an important detail to pay attention to.

What is Right for You?

Each species of bird has eggs of different shapes and sizes. These variations mean it is important to do your research before choosing an incubator, especially if you’re choosing one with automatic turning capabilities. Most eggs need to be turned multiple times a day, with some eggs needing to be turned multiple times an hour. If you don’t have time to sit next to your incubator to make sure your eggs are turned on time, then an automatic turner is highly recommended.

Some automatic turners also have the feature of a countdown clock, so that turning can be stopped two days before hatching. This is a safety feature for your chicks, as turning while hatching can result in inverted hatches or even injuries from the moving parts in the incubator. In nature, chicks will start peeping in the days leading up to hatching, which causes the broody hen to stop turning the eggs.

Chicks that are turned too close to hatching may end up in the wrong position and fail to hatch. Instinct can be replaced with a countdown clock, or by keeping track of the days manually if your incubator doesn’t offer this feature. In general, you should stop turning chicken eggs on day 19 (day 2 on a countdown clock).

Brinsea Incubators

Technology has come far in incubation, but we must be careful to always look back to nature to see how to model our devices. Copying nature in turning, cooling, and in other aspects can help us to hatch and raise healthy, well-developed chicks. For fowl, what matters most in turning is that the action is achieved, not so much how it is achieved. For non-domesticated exotic species, angle and frequency are key, so the method of turning and the programmability are important factors.  

At Brinsea, we offer a range of incubators to choose from, from small, 7-egg models to large incubator cabinets. All of our incubators that offer automatic turning will turn in a random or alternate direction every turn. We have the right incubator to meet your needs; all you have to do is visit our website today to start incubating!