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 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.

FUDGE

Fudge is an interesting candy because if you do not pay close enough attention to the science behind it, it will not turn out right at all. The trick to making a smooth fudge starts at the beginning.

Making sure that you have a good pot to cook it in is essential. Copper kettles are most commonly used in the fudge making business due to their heating properties. Copper is a good thermal conductor and heats up evenly which is very important as to prevent burning. It could also affect the temperature the fudge is cooked to if the thermometer is resting on a "hot spot".

At about 220 degrees Fahrenheit (5/9*(220 + 40) - 40 ~ 104 degrees celcius), after consistently heating, the temperature will stop rising for a good deal of time. This is because the sugar in the fudge is going through a phase change (a phase change is when something changes from one state to another without a change in its chemical composition. ie: water changing to ice or steam). During a phase change, energy is going into the process without a change in temperature. In the case of fudge, the sugar is crystallizing which is a vital part of the process because it would not set up correctly otherwise. The final temperature of the fudge will be near 130 degrees Fahrenheit which actually varies with humidity! Days with more humidity the fudge will actually need to be cooked to lower temperatures than on hot days (if the humidity changes significantly, what would be a perfectly good temperature the day before might result in a rock hard fudge or a gooey pile of sugar). This is because less water from the fudge will be evaporated so if the temperature is raised the fudge will turn out hard.

Next is cooking the fudge and beating it which allows the fudge to form microcrystals and set. If the fudge is beaten prematurely, too many crystals will form and the result will be an unattractive, rough looking loaf of fudge. This can also happen if only table sugar is used in the recipe. If different types of sugars are used such as corn syrup and invert sugar, they will interfere with eachother's crystallization processes and reduce the chance of crystallzing prematurely. If nuts are added to the fudge the cooking temperature of the fudge will actually have to be lowered slightly as the nuts will absorb some of the water from it.

FUN FACT: Chocolate, the main component of fudge, was first mass produced in 1770 with James Watt's improvements to the steam engine that mechanized the cocoa bean grinding process.

FREEZE DRYING

Food preservation is one of the most important technologies that exists. Whether it is canning, refrigerating, or freezing, we have come to depend on our ability to preserve foods. Freeze drying is one of the most effective methods of food preservation because it allows food to keep for years while minimally affecting its structure.

Freeze drying food is removing the water from it while leaveing the structure and composition. Removing the water keeps the food from spoiling because microorganisms need water to survive. It also significantly reduces the weight of the food. Astronauts take freeze dried food on space missions because of how long they last and how little space is needed to store them.

Just evaporating the water out of food will change the composition of the material and will not completely rid of the water. For this reason freeze drying is used sometimes instead. In the freeze drying process, the water goes from the frozen solid state to the gas phase without ever becoming liquid by lowering the pressure and raising the temperature (see graph).

Is how this works is food is placed in a chamber and compressors are used to lower the temperature and freeze it. Then, a vacuum removes air, lowering the pressure below 0.06 ATM. The temperature inside the chamber is barely heated and the frozen water turns directly into vapor and exits the chamber where it condenses onto the refireration coils. This process takes a very long time so not to disturb the original structure of the food.

FUN FREEZE DRIED FACT: Conscious about the environmental impact associated with cremation and embalming fluids, the Swedish company Promessa Organic has come up with the solution of freeze drying the dead.

BOILING WATER
Are you curious how you're able to heat your Ramen water so quickly? Every time you turn put water on the stove a process known as convection occurs. Convection is heating by the movement of fluids and without it, heating water would take a very long time as water is not a good conductor. As the water in your pot is heated, the warmer, less dense water rises to the top while the cooler water sinks down to the bottom above the heat source where it is then heated until it is hotter and less dense than the warm water above it and the cycle repeats itself.

If you have ever been to a coffee shop or Seattle you are probably familiar with the term "espresso". When someone orders an espresso, however, they are not ordering a type of coffee bean but a process.

The basic espresso machine is very simple. Is all it is doing is using pressure to push water through ground coffee beans and into your cup.

The water is heated up in the bottom of the machine and as the pressure builds the water is forced into the filter where the coffee is located and then as the pressure continues to increase it is forced through the spout. A good shot of espresso should take approximately 25 seconds to get through the coffee. Because the pressure depends on the temperature of the water, the pressure may not be sufficient at the recommended brewing temperature to move the water through the filter and spout. Because of this, there are electric machines with pumps that pump cold water into a heating chamber at high pressure.

~MICROWAVES~

Microwaves are a really cool way of heating things (literally, unlike an oven, the air in a microwave doesn't actually heat up). They use radio waves at a frequency of approximately 2,500 megahertz. Water, fats, and sugars absorb radio waves at this frequency, but most plastic glass and ceramics do not. This means that microwaves are very efficient with their distribution of energy because energy is only going into what you want heated up! Useful note: the waves in your microwave are reflected by metal so unless it's your roommate's microwave, use a plate. Click on the electromagnetic spectrum to see what happens if you do "forget" to heed my advice.

Have you ever noticed that your food you heat up in the microwave doesn't come out crisp like it does in an oven? That's because unlike microwaves, ovens use conduction to heat its contents. The air in the oven is heated up and slowly penetrates through its food from the outside in. The hot, dry air of the oven evaporates the moisture of the outer layer of whatever you're cooking, making it crisp (ie: bread crust). Microwaves, however, don't heat up the air inside but instead excite certain atoms of what you are cooking so baking bread in the microwave probably won't turn out as nice as you'd like.

Fun tip! Do you hate the fact that your frozen corn dogs come out without the crispy crust that you love? Try wrapping them in cardboard which will heat up and act as hot air in an oven, allowing the crust to become crispier. Now everyone will think that you're a great cook without ever discovering that you don't even know how to work an oven!

Bonus tip: If you live with your parents and don't like seeing your mom angry, put a paper towel over the food you are heating.

These fun little contraptions always add to the lively atmosphere of Thanksgiving dinner and might be your only source of entertainment if Grandma still hasn't invested in a color tv. Though they appear to work off of magic, there's actually science behind the mystery.

These are made of a stick with a spring in a case held into place by a soft metal in the tip of the casing. The metal melts at about 185 degrees fahrenheit, which is the desired cooking temperature of a turkey. When the metal melts the potential energy from the spring turns into kinetic energy which pushes the spring up so you don't have to go through the annoying hassle of reading 185 F ...5/9 * (185 + 40) - 40 = 85 C off of a thermometer ever again!

Fun fact that the pop up turkey timer manufacturers don't want you to know.... You can reuse them! Is all you have to do is heat the tip of the thermometer again by putting it into hot water (185 degrees F) which will melt the metal and you can then push the stick back down and allow it to cool into place.