Ask the experts: Eggs’ use-by dates
Q: "When I buy eggs in the supermarket, they have a use-by date on the packaging. If I buy a tray of eggs in the vege shop, there is no date and I have no idea how old these are. One vege shop I know has a quick turnover as they are always running out and I love these eggs. But I went to another recently and thought I'd better test an egg before I used it and it floated in water. The rest of the tray was the same so I threw them in the rubbish. What a waste of money when you haven't got much! Why don't the vege shops have to supply a use-by date?"Helen
A: Caroline Gunn, director of Food Safety Services Ltd in Napier, explains:
"Under the Food Standards Code, food for retail sale must have a label bearing content and nutritional analysis of the food item. There are, however, several exclusions from these food labelling requirements and one is where 'the food is other than in a package'. This means when eggs are sold open in a tray at the local vege shop they are not enclosed in a carton (or package) and therefore they do not have to have a label or best-before date. Another exemption from labelling requirements is for whole or cut fresh vegetables and fruit.
One way of determining how fresh the eggs you buy are is to put them in a saucepan of water. Fresh eggs will settle to the bottom and rest horizontally, one week old eggs tend to rise up slightly, 2-3 week old eggs will settle to the bottom vertically, large end up; and old eggs (5 weeks plus) just float up to the surface. This is due to the air cell under the shell that starts forming when the eggs are first laid, and as the eggs age it keeps getting bigger (you can see this air cell when you peel hardboiled eggs and there is a little dip in the white at the end).
Having said that, eggs are perfectly fine for use for up to four weeks if stored correctly in your fridge. Because eggs are porous and absorb flavours and odours, they are better stored in a carton actually in the main part of fridge, which has a more consistent and cooler temperature, as opposed to the refrigerator door where the manufacturers usually put egg shelving.
I sympathise with you Helen; it's frustrating to purchase a food then find its quality is poor. I would suggest that those eggs you purchased may not have been too old but had probably been left out on display all day (and night) in warm conditions in a tin shed, which meant they went off much quicker than if they were refrigerated. I would be inclined to return them."