Marks & Spencer has launched packs of “guaranteed” double-yolk eggs, costing £2.75 for six.
The so-called “double yolkers” are free range and sourced from pullets in the early weeks of lay, a period in which larger-than-average eggs will often have more than one yolk.
A final confirmation comes once the eggs are candled, allowing M&S to guarantee two or more yolks.
The British Egg Industry Service estimate that, in general, fewer than one in 1,000 eggs are double yolked.
See also: Top tips on marketing your eggs
In January, pullet eggs featured in an episode of Jamie Oliver’s Friday Night Feast. The show highlighted that up to a billion are sold into processing at a fraction of their retail value.
M&S said the launch was part of a range of speciality eggs, including Araucona blue and Maran Island browns.
Ali Rodham, a product developer for the retailer said: “We’re really excited to be selling double yolkers. We think they’re cracking, and we’re sure our customers will too.
“Perfect for people who think the yolk is the best bit of the egg, not only are they delicious, but they are healthy, too.”
Much of the nutrition in eggs – including vitamins B12, B6, A, D, K, E and folate – is found within the yolk, she added.