The truth is that you can't just look at an egg and know whether it's fertilized or not. But if you purchase your eggs from a grocery or commercial store, there is a high chance it's not fertilized.
One of the challenges eggs consumers and poultry farmers encounter is to exactly know if a chicken egg is fertilized or not without cracking it.
For most poultry farmers, it is not a big problem for them, unlike egg consumers. They seem to instinctively know when a chicken egg is fertilized.
Even if you are not a farmer, there are proven ways to know if a chicken egg is fertilized. No one wants to eat a newly hatched chicken!
Learning if a chicken egg is fertilized can ease your fears. How on earth do farmers know when a chicken egg is fertilized?
This article will discuss the methods often used by farmers to know when a chicken egg is fertilized without breaking it open.
Do hens lay fertilized eggs without a rooster?
For a chicken egg to become fertilized, a rooster has to mate with a hen. If you don't have a rooster around, there is no point confirming if an egg is fertilized.
Furthermore, a fertilized egg is not always produced when a rooster gets to mate with a hen. Some roosters' sperm are not just fertile.
How soon after mating are eggs fertilized?
Eggs can be fertilized as soon as 24 to 48 hours after mating.
Here’s how it works:
- When a rooster mates with a hen, he transfers sperm into the hen’s reproductive tract.
- The sperm can stay alive inside the hen for up to 2 to 3 weeks, sometimes even up to 4 weeks.
- During this time, the sperm can fertilize any eggs the hen lays.
Timeline Overview:
| Event | Timeframe |
|---|---|
| Mating | Day 0 |
| Fertilization (first egg) | 24 to 48 hours after mating |
| Fertilization continues | Up to 2-3 weeks (sometimes 4 weeks) |
So, if a hen mates with a rooster today, the eggs she lays in 1-2 days could already be fertilized, and many of her eggs after that can be fertilized for several weeks without another mating.
3 Ways Farmers Tell If a Chicken Egg is Fertilized
As a young boy, while growing up, I sometimes wondered how my father, who was a poultry farmer at that time, was able to differentiate between fertilized chicken eggs and non fertilized ones.
Then I thought my father must be a genius egg whisper. Apart from this, he could even tell which egg would hatch and which would not.
But years later, I found out that there are ways to know without cracking the egg.
1. Candling
Candling is one method farmers use to know if a chicken egg is fertilized. What does candling involve?
Candling involves bringing a chicken egg near a light source. By doing this, your goal is to see the content of the egg via the shell of the egg.
One common light source that farmers use is candles. "Candling" was obviously coined from candles. Bring the egg near a lit candle, if you can see a mass inside the egg, it means the egg is fertilized.
On the other hand, if you don't see a developing mass inside the egg, or if the shell is opaque, it means the egg is not fertilized.
Unfertilized chicken eggs will never grow veins. Candling is the commonest method that farmers use to determine if an egg has been fertilized
Always remember that the more visible the content of the chicken egg is, the closer it is to hatching. Along with the developing mass, you'd see a network of veins surrounding it.
2. Water Method
The water method is another old trick that farmers employ to know if an egg is fertilized. To determine whether an egg is fertilized, pour warm water into a bowl. Put an egg inside it.
If the egg is unfertilized, it will sink to the bottom of the bowl. If it's fertilized, it will float.
A fertilized egg is slightly heavier than an unfertilized egg. The air and weight composition make all the difference. This method is not always accurate. It is usually more accurate at the late stage of incubation.
3. Crack It Open
To simply know whether an egg has been fertilized, crack it open! This is the most reliable method to know whether an egg has been fertilized.
There are things to look out for after cracking the egg open. When you crack an unfertilized egg open, you'll see a blastodisc (a whitish small spot on the egg yolk).
On the other hand, when you crack a fertilized egg open, you'll see a blastoderm (a whitish spot with a ring surrounding it looking like a bullseye).
Can I tell if an egg is fertilized just by looking at its shell?
No, you cannot tell if an egg is fertilized just by looking at the shell. The shell of a fertilized and an unfertilized egg looks exactly the same. Fertilization happens internally before the egg is laid, and the shell forms around the yolk and albumen (egg white), regardless of whether it’s fertilized or not.
Are Fertilized Eggs Safe To Eat?
About 6 billion eggs are consumed yearly in the United States alone. This includes both fertilized and unfertilized eggs.
Without beating around the bush, fertilized eggs are completely safe to eat. Most of the eggs that people buy from poultry farms are not fertilized.
What can make an unfertilized egg unsafe to eat is when you decide not to properly wash the egg. Also, a fertilized egg can become unsafe if you have allowed too much time to pass before collecting it.
If you want to get as many nutrients as possible from a fertilized egg, then you should go for fresh eggs, the longer an egg is stored, the more it loses its protein value.
There is no point for a farmer to keep a rooster and a hen together to produce eggs. If a hen is properly fed, it will produce enough eggs.
Do fertilized eggs taste different from unfertilized eggs?
No, fertilized eggs do not taste different from unfertilized eggs.
The flavor, texture, and nutritional value of an egg are almost identical whether it's fertilized or not—especially if it's fresh and hasn't started developing into an embryo.
Most people wouldn't be able to tell the difference when cooking or eating them.
Why There's No Taste Difference?
Development only begins with incubation: Eggs need to be kept warm (like under a hen or in an incubator) for about 24 hours to start developing. Without this warmth, the egg will stay the same as any other egg.
Storage conditions matter more than fertilization when it comes to egg taste. Freshness, the hens' diet, and storage conditions affect egg taste more than fertilization.
What might cause confusion?
Sometimes fertilized eggs may show tiny blood spots or tissue spots, but this is not harmful and doesn't affect taste. These can also happen in unfertilized eggs.
If an egg was accidentally kept warm and started developing (partially forming veins or an embryo), it could have an unusual appearance or texture. However, it's unlikely you'd eat such an egg by mistake unless it was incubated.