Humans have been eating chicken eggs for thousands of years. Chicken eggs provide an excellent source of protein and nutrients. However, most of the chicken eggs that are consumed are unfertilized. This leads to the question – do humans ever eat fertilized chicken eggs?
What are fertilized eggs?
Chicken eggs have the potential to become fertilized when a rooster mates with a hen. If the hen’s eggs become fertilized, the eggs will contain a developing embryo inside that will grow into a chick if incubated.
Fertilized eggs look the same on the outside as regular unfertilized eggs. The only way to know if an egg is fertilized is to crack it open and inspect the inside. A fertilized egg will contain a white spot on the yolk which is the developing embryo.
Do humans consume fertilized chicken eggs?
Short answer: Generally no, humans do not intentionally eat fertilized chicken eggs. However, it is possible that some fertilized eggs may make it into the food system accidentally.
The commercial egg industry goes to great lengths to ensure that the eggs being sold and consumed are not fertilized. Egg producers keep hens and roosters separated to prevent fertilization. Any fertilized eggs laid are removed from the production chain.
Reasons fertilized eggs are avoided:
- Taste – The developing embryo can affect the taste and texture of the egg.
- Morality – Some consumers oppose eating eggs containing a developing lifeform for ethical reasons.
- Food safety – Fertilized eggs decay faster and are more prone to contamination with bacteria like salmonella.
So while fertilized chicken eggs are edible, the egg industry considers them undesirable and takes steps to prevent them from reaching consumers.
Are there any examples of people intentionally eating fertilized eggs?
While uncommon, there are some instances where people consume fertilized chicken eggs intentionally:
- As a novelty food – Some restaurants offer fertilized egg dishes to customers looking for an unconventional dining experience. These are often eggs that have been fertilized and partially incubated before cooking.
- As a delicacy – Fertilized duck or goose eggs are eaten in places like China, the Philippines and Vietnam. These are called “balut” and are boiled and eaten while still in the shell.
- Personal/cultural preferences – There are some individuals and groups who choose to eat fertilized eggs for perceived health benefits or as part of their culture.
However, these instances are rare exceptions. The vast majority of eggs consumed, even in places where fertilized eggs are a delicacy, are still unfertilized chicken eggs.
Reasons fertilized eggs may accidentally enter the food supply
While systems are in place to prevent fertilized eggs from reaching consumers, it is still possible for some to slip through accidentally due to:
- Infrequent mating of hens and roosters – Hens can sometimes come in contact with roosters and lay fertilized eggs before being separated back into hens-only housing.
- Underdeveloped embryos – Very early embryos are difficult to detect during candling inspections.
- Improper egg handling – Cracks or other damage can allow fertilized eggs to slip past quality control points.
- Backyard chicken coops – Eggs from small home flocks are less likely to be from hens isolated from roosters.
The number of fertilized eggs reaching consumers from these accidental sources is still very small. But it demonstrates that it is possible for people to unintentionally eat fertilized chicken eggs if they are not removed.
Can you tell if an egg is fertilized by looking at it?
It is impossible to tell if a raw chicken egg is fertilized just by looking at the outside of the shell. Fertilized and unfertilized eggs are identical externally.
The only way to confirm if an egg is fertilized is to crack it open and examine the inside contents:
- Look for a white spot on the yolk – This is the developing embryo which starts as a white disc.
- In later stage embryos, look for recognizable body parts – Eyes, a beak, feet, and feathers can sometimes be visible in more developed fertilized eggs.
- Floating in water – Fertilized eggs will float in water while fresh unfertilized eggs will sink. But this is an unreliable test.
Candling eggs by shining a bright light through them can reveal some internal signs like blood vessels. But this takes specialized knowledge and equipment.
Simply checking the outside shell offers no clues about fertilization. You have to crack the egg open and look inside closely to know for sure.
Does cooking make fertilized eggs safer to eat?
Proper cooking does make fertilized eggs safe for consumption from a food safety standpoint. Heat from cooking will kill any bacteria like salmonella.
However, even with cooking, there can still be textural and flavor changes if the embryo has had a chance to develop. The visual appearance of the embryo can also be unappalling to some.
Here are some tips for safely cooking fertilized eggs:
- Cook until yolk and white are solid – Fry, boil, or bake until no liquid egg remains.
- Cook to an internal temperature of 160°F/71°C.
- Discard eggs with unpleasant odors or visible embryo development.
Thorough cooking is recommended when preparing any eggs to eliminate risks of foodborne illness, whether fertilized or unfertilized.
Nutritional content of fertilized vs unfertilized eggs
Several studies have compared the nutritional values of fertilized and unfertilized chicken eggs. The results show little significant difference:
| Nutrient | Unfertilized | Fertilized |
|---|---|---|
| Calories | 71 kcal | 70 kcal |
| Protein | 6.3g | 6.3g |
| Fat | 4.8g | 4.7g |
| Carbs | 0.4g | 0.5g |
Both fertilized and unfertilized eggs contain complete proteins with all essential amino acids and are considered very nutritious.
When it comes to nutritional content, there is little advantage of one over the other. The main differences have to do with flavor, texture, and personal preference.
Do some cultures prize fertilized eggs?
Although most Western cultures avoid eating fertilized chicken eggs, some other cultures around the world consider them delicacies and even prize them for purported health benefits:
China
In China, fertilized duck eggs are preserved in urine, clay, ash or salt for several months then cooked in tea to produce “pidan”. It is valued for its unusual grayish-green yolk color and pungent aroma. Some believe it has medicinal qualities.
Philippines
“Balut” is a popular Filipino street food consisting of fertilized duck eggs that are boiled and eaten straight from the shell. They are considered an aphrodisiac and source of protein. Balut are available from street vendors and often eaten with salt or vinegar.
Vietnam
Fertilized duck eggs containing semi-developed embryos are also eaten in Vietnam. In Vietnamese, they are called “hot vit lon” meaning windy egg. The eggs are consumed for purported health benefits.
Other examples
– In Thailand, fried fertilized chicken eggs are called “kai khao”
– In Indonesia, “telur asin” are fertilized duck eggs preserved in brine.
– Some African tribes consider raw fertilized eggs a delicacy.
While not as universally consumed as regular eggs in these cultures, fertilized eggs still hold an important place in certain regional cuisines and folk medicine traditions. The practice persists even when most eggs consumed are still unfertilized.
Are there health risks to eating fertilized eggs?
When properly cooked, fertilized chicken eggs pose minimal additional health risks compared to regular eggs:
- Salmonella – Thorough cooking kills Salmonella, the biggest risk in raw eggs.
- Biogenic amines – These compounds sometimes form during incubation but cooking reduces them.
- Allergies – Those with egg allergies are not likely to have issues beyond their normal reaction.
- Nutritional content – Minimal variation between fertilized and unfertilized eggs. Both are highly nutritious.
The main safety consideration is that fertilized eggs decay faster. So proper cooling, storage, and cooking is important. But overall, fertilized chicken eggs are generally considered safe to eat when prepared properly.
Of course, personal sensitivities like taste aversion or ethical concerns should also be considered. But the health risks are minimal. Those eating eggs like balut with more advanced embryos may face higher risks from biogenic amines if not properly cooked.
Conclusion
While humans generally avoid eating fertilized chicken eggs, it is possible some fertilized eggs accidentally make their way into the food supply. A few cultures even prize certain fertilized eggs as delicacies or health foods.
However, the overwhelming majority of chicken eggs consumed around the world are unfertilized. The egg industry goes to great lengths to deliver only infertile eggs to consumers.
Proper cooking kills bacteria that could be present and addresses some health concerns over fertilized eggs. But personal preferences on flavor, texture, and ethics may still make fertilized chicken eggs unappealing as a food to most. Their consumption remains relatively rare.
So in summary, while possible to eat safely if cooked, humans do not intentionally consume fertilized chicken eggs in most parts of the world. Unfertilized eggs remain the norm for the human food supply thanks to practices designed to deliver only infertile eggs to grocery stores and consumers.
