In July of 1971, Diane Hainsworth of Hainsworth Poultry Farms, located in Mount Morris, New York, found an egg that contained a record-setting nine yolks, per Guinness World Records. Eggs containing multiple yolks are perfectly safe to eat, says Egg Safety. And in addition to very young and mature hens that are more likely to produce these multi-yolk eggs, some breeds of chickens, like the Buff Orpington, are also more likely to lay these rare eggs, according to Food & Wine.
Though eggs with multiple yolks are safe to eat, you may need to modify your recipe should you encounter a double-yolker and choose to cook with it. Sauder’s Eggs points out that double-yolk eggs are a bit larger than the average chicken egg, and nutritionally, they’re roughly equivalent to a jumbo egg. If you’re baking or preparing a recipe that calls for egg yolks, you’ll want to make sure you don’t throw off the ratio of protein to fat and sugar by using a double-yolk egg in place of an ordinary, single-yolk egg. And on the extremely rare chance you should crack an egg and find 10 yolks inside, you should probably reach out to Guinness.