We love our eggs, eating an average of two a day. But how do we tell the difference between them.
How do we know, for example, those free-range egg we are paying extra for are in fact free-range.
A Wellington scientist has developed a way of finding out exactly if the egg that you are eating is the egg you think it is.
Karyne Rogers has been breaking eggs on our behalf to find out.
Ms Rodgers wants our poultry industry to adopt it, so we can all be assured the egg we are buying in the supermarket or being served at a café, is exactly what we paid for.
After a year of research she has discovered it is the type of nitrogen in an egg that appears to be the key indicator of the chicken's diet.
Ms Rodgers has developed a test that shows the type of nitrogen in an egg. In turn that indicates whether it was laid by a caged bird or a free-range one and whether it is organic.
Now more than ever, she says we need to be assured exactly what is in our food.
Ms Rodgers says this test has the potential to help consumers and the poultry industry, which produces $200 million worth of eggs a year, including $3 million in exports.
Ms Rodgers says as people ask more questions about the origin and authenticity of food, the test she has developed could be used on other foods we eat and export such as meat and dairy.