Over the summer of 2020 Charli Lello from Hertfordshire hatched three ducklings from eggs she bought in Waitrose. Charli put the eggs in an incubator as an experiment to pass the time while she was furloughed. She got the idea after watching a video on Facebook of someone who had successfully hatched quail eggs that had been bought from a supermarket. Charli said the ducklings, which she named Beep, Peep, and Meep, would live a happy life with her pet chickens.
This is not the first time someone has hatched a duckling from a Waitrose egg. In 2019, 14 year old William Atkins bought an incubator on eBay and half a dozen free range duck eggs and hatched a duckling called Jeremy.
But how easy is it to hatch a supermarket egg?
For a supermarket egg to hatch it must have been fertilised. And the vast majority of eggs on supermarkets’ shelves, whether they are from ducks or chickens, will not be fertilised. This is because in commercial egg production male and female chicks are separated at about a day old. Male chicks will be slaughtered as they obviously don’t lay eggs and chickens bred for laying eggs have been designed for egg production and not gaining weight, so they are not viable as a source of meat either.
Of course, the odd sexing mistake does happen and this is more likely to happen in flocks of ducks or quails where it is more difficult to identify males and females. The ducklings that Charli hatched came from white-feathered ducks which a Waitrose spokesman said were “notoriously difficult” to sex.
Free-range birds which are kept in an outdoors environment may also encounter wild birds giving rise to the potential of a fertilised egg. And buying eggs from farms or smallholdings where hens are allowed to wander freely means the chance of obtaining a fertilised egg increases.
If you do buy a fertilised egg you probably won’t know you’ve done so unless you incubate it and candle it a few days later. Candling an egg involves shining a bright light through it so you can see inside it. If an egg is fertilised and incubation has started to work you should be able to see the development of veins or even a beating heart.
Fertilised eggs are perfectly safe to eat and unless an egg is incubated, either by putting it in an incubator or from a hen sitting on it, an embryo will not begin to develop. In fact, before the days of mass egg production almost all eggs would have been fertilised as hens and cockerels were allowed to mix freely.
Once you have cracked open an egg you can tell whether it was fertilised by the size of the nucleus. In an unfertilised egg the nucleus is a tiny white spot on the yolk, whereas in a fertilised egg it will have formed a ring.
And despite a prevalent myth, blood spots are no indication of whether an egg is fertilised or not. Blood spots are a normal part of the egg-laying process, the result of a blood vessel rupturing in the chicken’s reproductive tract when the egg was formed, and they are perfectly fine to eat.