Whether to wash eggs is the biggest and most controversial issue in today's backyard chicken industry. While it is perfectly fine not to wash eggs for consumption until ready for use, it turns out that washing eggs for hatching may be more beneficial for increasing hatching success.
One of the last steps after a hen lays an egg is to coat the egg with a cuticle, or brush. The cuticle is a natural defensive coating on the egg that fills the egg's pores and protects the eggshell from bacteria.
Washing the cuticle off an egg may seem counterproductive to the goal of achieving optimal hatchability, but understanding the moments after a hen lays an egg is key to understanding the need to wash hatching eggs. Eggs laid are particularly susceptible to microbial contamination.
While hens coat their eggs with a cuticle before laying, the cuticle is not fully formed until the egg cools down and the cuticle dries.
The time it takes for the egg to cool down and the cuticle to dry depends on the location and conditions of the egg-laying site. Clean things should never come in contact with dirty things. The contents of an egg are usually sterile when the egg is laid. A dirty nest box or egg-laying site can quickly alter the cleanliness of a freshly laid egg.
Since both eggs and feces are expelled through the bird's cloaca, nest boxes, and other egg-laying sites are not usually the cleanest places for eggs to be laid. This environment and the unfortunate natural course of the egg-laying cycle provide an opportunity for bacterial contamination.
Pathogens found in feces can penetrate the egg pores within less than 30 minutes after the egg is laid, during the egg cooling period. A freshly laid egg is at the same temperature as the hen when it was first laid (107 degrees Fahrenheit). As the egg cools, its contents shrink and begin to draw in air and other bacteria from the shell through the pores before the cuticle dries and becomes functional.
The best way to limit contamination immediately after an egg is laid is to ensure adequate egg collection frequency, clean nest boxes, and egg-laying sites frequently, and disinfect eggs while they are still warm.
Large commercial hatcheries have several methods for disinfecting hatching eggs, including ozone fumigation and ultraviolet light, but for backyard breeders, the easiest, cheapest, and most effective method is to wash the eggs.
A specific automatic egg cleaner machine is required to ensure the effectiveness of washing eggs to eliminate contamination. Below is a step-by-step guide to safely washing hatching eggs.
Collect eggs frequently to minimize debris on the eggs. The more bacteria on the eggshell, the higher the chance that bacteria will enter the egg and contaminate the egg contents.
Washing Eggs
Wash the eggs with an automatic egg cleaner machine. Temperatures of 98-1050F are best for preventing contamination. Warm water expands the contents of the egg, helping to expel any previously absorbed bacteria. Avoid using cold water as it will further introduce more bacteria into the egg.
Bleach Solution
While the eggs are still wet but will soon dry, spray the eggs thoroughly with a diluted 10% bleach solution as a disinfectant. Allow them to air dry. The bleach solution, while not strong enough to affect the contents of the egg, will help kill any remaining bacteria that was previously absorbed by the egg but not expelled by the egg during the washing process.
Further proof that washing hatching eggs is necessary is that dirty, unwashed eggs are at a higher risk of cross-contamination in the incubator. An excessive number of dirty eggs in the incubator is probably the biggest cause of poor chick quality and first-week mortality.
A cleaning procedure during the incubation process using an automatic egg cleaner machine is the best way to remove bacteria before hatching. This extra cleaning step will almost immediately increase hatch success rates and save you from having to worry about a possible unsuspected rotten egg explosion during the incubation process.
