EGGS
"A ""A Hne"A hen is only an egg's way of making another egg." ~ Samuel Butler making another egg."
"Besides for being a staple ingredient in cookie dough, we like eggs because there's lots of science involved with them." ~Blake Rider
One of the most notable characteristic of an egg is how much an egg white can foam up. Why does this happen?
Eggs are approximately 90 percent water and 10 percent protein. There is an electrical attraction between water molecules (for this reason you won't get any results from trying to whip up water alone) and when you beat them you are allowing the proteins to break apart the water molecules. When they get farther apart, the electric attraction decreases which allows the egg whites to spread out and bonds to form between the proteins.
Over beaten eggs really means that too many bonds formed between the proteins and you can actually help to prevent this by adding vinegar. Vinegar is an acid so its particles are positively charged. These charged particles join charged protein, neutralizing them and making them less likely to form bonds with other proteins.
Cold eggs whites will be more difficult to beat into a foam, because the air bubbles will be smaller and more difficult to seperate than egg whites at room temperature.
Boiling eggs: Have you ever hard boiled an egg and it ended up with a flat edge on one side?
Eggs have a small pocket of air trapped in-between the flatter end of the egg and the shell. When the eggs are boiled the temperature rises and so does the
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volume of the air pockets which do not allow for the flatter ends to cook up against the shell and will, therefore, end up with one side flatter.
Solution? If you happen to be an egg connoisseur and want that full egg shape is all you have to do is poke a hold with a small needle through the outer membrane of the shell. As the pressure builds, the air will be pushed out into the boiling water (so you should see a stream of bubbles coming from the egg) but the egg white will not be able to escape through the inner membrane. The result will be a perfectly egg shaped egg.
Discoloration: Anyone who has hard boiled eggs before probably has noticed that the yolk will sometimes have a dark greenish tint to it. Why does this occur?
Egg whites have lots of sulfur atoms which are freed when heated and form hydrogen sulfide with the hydrogen atoms from the albumen (egg white) and then diffuse in all directions. Any of the hydrogen sulfide that reaches the yolk will react with all of the yolk's iron and form ferrous sulfide which is what you see.
Solution: You can decrease this process by boiling the eggs only long enough to cook the yolks and then immediately put them in cold water which will cool the gas on the outer part of the shell first (and therefore the pressure) and the ferrous sulfide will diffuse toward this new lower pressure area and away from the yolk.
FUN EGG FACT: Hydrogen sulfide provides a nice smell to cooked eggs but too much of this is what actually gives rotten eggs their foul odor.