A Coles customer made an extraordinary find in eggs she bought from the supermarket – with the special discovery even prompting her to buy a lottery ticket.
Brisbane woman Joanna Schulz was stunned after working her way through the carton of Coles 700g Free Range eggs to discover they all contained a double-yolk.
Ms Schulz said after initially discovering three double-yolk eggs in the carton, her curiosity got the better of her so she and her family decided to cook up the entire batch.
"It felt like Christmas," she told Yahoo News Australia. "That feeling of anticipation before cutting open each egg and then the astonishment of what we were seeing in front of us. Each and every one had two yolks."
Ms Schulz said she felt compelled to keep trying to ride her seemingly lucky wave. "Who knows? I might just win division one and two," she laughed. And she might even be onto something there, as cracking open a 'double yolker' is considered a symbol of good luck and prosperity in many cultures.
How double yolk eggs are produced
Double-yolk eggs are produced when a hen's ovary becomes overly productive, resulting in two yolks instead of one – a similar process to the occurrence of human twins. Typically, the ovary produces one yolk per day, but in the case of double yolkers, it produces two in quick succession. As a result, the two yolks merge together during the egg-laying process and get laid as a single egg with two yolks inside.
The occurrence of two yolks is more common in younger hens whose reproductive systems are still developing, and it's generally considered a genetic abnormality that doesn't affect the egg's nutritional value. As it happens, the world record for the most yolks inside one eggshell is nine.
Odds of getting a double yolker
While the statistics indicate that the probability of finding a double-yolk egg is one in 1,000, experts suggest the chances of discovering more than one double-yolk egg in the same batch are surprisingly high, under the right circumstances.
Aussie science guru Dr Karl Kruszelnicki explained on ABC Radio National that there are several other factors involved in the production of double-yolk eggs, which ultimately increase the likelihood of finding more than just one in a single carton.
"First, double-yolk eggs are usually larger than single-yolk eggs," Dr Karl explained. "Eggs are usually sold in the sizes of small, medium and large. So if you find a double-yolk egg in a carton of large eggs, the chances are higher than normal that another double-yolk egg could be found."
Dr Karl also noted eggs within a single cardboard carton are typically sourced from the same flock of chickens, which are often the same age. This, in turn, raises the probability of a second double-yolk egg appearing if you've already found one.