Eggs...Eggs...Eggs...
How do we tell the difference between an older egg and a fresh egg? How do we know we’ve boiled an egg too long? Does it really matter if eggs are fresh? How can we tell a cracked egg is fresh? Is there a time when we don’t want to use a fresh egg? Do we really need to know how old they are prior to preparing them? If you’ve ever made a large pan of scrambled eggs, and discovered that the last egg you added to the bowl was rotten, you know that there is some information that’s good to know when making egg dishes.
Candling is a technique used to evaluate eggs for freshness in unbroken eggs. A small flashlight works great and will
not only expose the porousness of the egg but will expose a quite visible air pocket in the bottom of each egg. A fresh egg will have an air pocket of approximately ½” diameter. An older egg will lose its carbon dioxide and take on air as the egg dries out and the protein becomes less stable and alkaline. The older air pocket will be close to 1” diameter. But this doesn’t mean the egg is bad by any means!
A quick way to tell if an unbroken egg is bad is to place it in a glass of water. If it floats to the top then toss it out.
When broken an older egg will have a more watery white area. The yolk will drift to the edge of the white area which is what has happened here in the picture to the left. This does NOT mean the egg is bad. You’ll quickly smell if a broken egg is rotten!
Hard boiled eggs peel better when the eggs are older. Plan ahead and buy your eggs a couple weeks early if you plan to hard boil them. I always make sure not to mix my eggs and when I buy a fresh batch I hard boil my older ones. The alkalinity causes them to peel much better especially when peeled when cool. To make the perfect hard-boiled egg place the water on the stove and start the heat. Place the desired number of eggs in the water and cover. Bring the water to a full boil for a few minutes then turn off the heat and cover the pan. Let it stand for 10 minutes. I like to test one before tossing the hot water but when you know they are perfect toss the hot water and rinse with cold water and place them in refrigerator. Try to eat them within a week. Put them on salads or make an egg salad sandwich or egg dip. Also, if you forget which eggs are hard-boiled just spin one on a table. The hard ones will spin uniformly. The uncooked eggs will wobble.
If the hard-boiled egg has a visible green rim around the yolk, the sulfur ring, it just means you’ve cooked it too long. Don’t worry as it won’t affect the flavor or nutritional value. Sulfur is present in the yolk and white equally. When the hydrogen in the white reacts with the iron in the yolk we get hydrogen sulfide which creates the
green color of Ferrous Sulfide or Fe S. This union is at the outer yolk rim. Cooling our cooked egg in cold water or ice helps eliminate this union.
A couple of other facts include a discussion about the appearance of the white of the egg. As it ages the stringy ropey looking white chalazae, that gives the interior structure, breaks down and loses visibility. This doesn’t affect the nutrition of the egg in any way. Yolk color is determined by the food provided to the hen. A dark yellow
is an indicator of high vitamin A content however, supplements can be given to hens that will increase their vitamin A if there is question. A light yolk produced by a supplemented hen won’t have a dark yolk so yolk color cannot be depended upon for nutritional disclosure.
I’ve already mentioned that older eggs make better hard boiled eggs because of the ease in peeling but there is one exception for me. Since the yolk of an older egg is closer to the edge of the white there will often be a breakdown when trying to build a deviled egg since the cup will lose structure and it's ability to hold the creamy yolk mixture.
And by the way...the white of the egg holds approximately 60% of it's protein vs. the yolk which has the other 40%. So feel free to eat the whole egg for nutrition and stop tossing your yolks!
How do we tell the difference between an older egg and a fresh egg? How do we know we’ve boiled an egg too long? Does it really matter if eggs are fresh? How can we tell a cracked egg is fresh? Is there a time when we don’t want to use a fresh egg? Do we really need to know how old they are prior to preparing them? If you’ve ever made a large pan of scrambled eggs, and discovered that the last egg you added to the bowl was rotten, you know that there is some information that’s good to know when making egg dishes.
Candling is a technique used to evaluate eggs for freshness in unbroken eggs. A small flashlight works great and will
not only expose the porousness of the egg but will expose a quite visible air pocket in the bottom of each egg. A fresh egg will have an air pocket of approximately ½” diameter. An older egg will lose its carbon dioxide and take on air as the egg dries out and the protein becomes less stable and alkaline. The older air pocket will be close to 1” diameter. But this doesn’t mean the egg is bad by any means!
A quick way to tell if an unbroken egg is bad is to place it in a glass of water. If it floats to the top then toss it out.
When broken an older egg will have a more watery white area. The yolk will drift to the edge of the white area which is what has happened here in the picture to the left. This does NOT mean the egg is bad. You’ll quickly smell if a broken egg is rotten!
Hard boiled eggs peel better when the eggs are older. Plan ahead and buy your eggs a couple weeks early if you plan to hard boil them. I always make sure not to mix my eggs and when I buy a fresh batch I hard boil my older ones. The alkalinity causes them to peel much better especially when peeled when cool. To make the perfect hard-boiled egg place the water on the stove and start the heat. Place the desired number of eggs in the water and cover. Bring the water to a full boil for a few minutes then turn off the heat and cover the pan. Let it stand for 10 minutes. I like to test one before tossing the hot water but when you know they are perfect toss the hot water and rinse with cold water and place them in refrigerator. Try to eat them within a week. Put them on salads or make an egg salad sandwich or egg dip. Also, if you forget which eggs are hard-boiled just spin one on a table. The hard ones will spin uniformly. The uncooked eggs will wobble.
If the hard-boiled egg has a visible green rim around the yolk, the sulfur ring, it just means you’ve cooked it too long. Don’t worry as it won’t affect the flavor or nutritional value. Sulfur is present in the yolk and white equally. When the hydrogen in the white reacts with the iron in the yolk we get hydrogen sulfide which creates the
green color of Ferrous Sulfide or Fe S. This union is at the outer yolk rim. Cooling our cooked egg in cold water or ice helps eliminate this union.
A couple of other facts include a discussion about the appearance of the white of the egg. As it ages the stringy ropey looking white chalazae, that gives the interior structure, breaks down and loses visibility. This doesn’t affect the nutrition of the egg in any way. Yolk color is determined by the food provided to the hen. A dark yellow
is an indicator of high vitamin A content however, supplements can be given to hens that will increase their vitamin A if there is question. A light yolk produced by a supplemented hen won’t have a dark yolk so yolk color cannot be depended upon for nutritional disclosure.
I’ve already mentioned that older eggs make better hard boiled eggs because of the ease in peeling but there is one exception for me. Since the yolk of an older egg is closer to the edge of the white there will often be a breakdown when trying to build a deviled egg since the cup will lose structure and it's ability to hold the creamy yolk mixture.
And by the way...the white of the egg holds approximately 60% of it's protein vs. the yolk which has the other 40%. So feel free to eat the whole egg for nutrition and stop tossing your yolks!
