In order for bubbles of steam to form, there needs to be some sort of irregularity within the volume of water—microscopic scratches on the inside surface of the pot will do, as will tiny bits of dust or the pores of a wooden spoon.
A handful of salt rapidly introduces thousands of nucleation sites, making it very easy for bubbles to form and escape. Ever notice how in a glass of champagne the bubbles rise in distinct streams from single points? It's a good bet that there's a microscopic scratch or dust particle right at that point. On a much grander scale, entire galaxies were formed when matter started to collect in gravity wells formed initially by tiny nucleation sites in the early universe.
This baffles scientists if there was nothing before the big bang, what then were these primordial nucleation sites? But that's neither here nor there or perhaps it's everywhere? A model of the universe in a pot of boiling water. Whoda thunk it, right? As we know, water is composed of individual molecules each with two hydrogen atoms and an oxygen atom; H2O.
The faster these molecules move around, the higher the temperature of the water. Now, these molecules have a magnetic charge, meaning that they are affected by electro-magnetic radiation which, by the way, is not as nefarious as it sounds—the light you see with your eyes and the heat you feel on your skin are both forms of electro-magnetic radiation.
Microwaves take advantage of this fact by shooting waves that cause water molecules to rapidly flip back and forth.
This motion in turn heats your food. Because microwaves allow so little energy to be lost to the outside environment the way, for example a gas burner will heat up the room , they are extremely efficient at heating water.
They're great for boiling water quickly without heating up the apartment. An electric kettle is also extremely efficient on this front. But there's one thing to be aware of. It's called superheating, and it really is as cool as it sounds.
Heat up water in a blemish-free container with minimal disturbance like in the microwave, for example , and because of a lack of nucleation points, it's possible to heat it well beyond its boiling point without it ever boiling.
As soon as some turbulence is introduced—a little wobble from the turntable, for example—bubbles burst forth, sending hot water all over the inside of your microwave. This doesn't happen on the stovetop, since heating from the bottom of the pot creates lots of convection currents the movement that occurs between relatively hot and cool regions of liquid or gas. It's a lot like my wife , who will quietly suppress tiny annoyances until the slightest disturbance will send her into an all-out rage.
In both cases, the results aren't pretty. It's best to avoid these violent outcomes by commenting on how nice your water's hair looks today or by sticking a wooden spoon in your wife before microwaving her. Here's an interesting one. Say I'm making a stew in the oven. I put my heavy Dutch oven in there, set the temperature to a moderate degrees, and walk away. Eventually, the water should come to a degree boil, right?
Actually, no. Because of the cooling effect of evaporation it takes a significant amount of energy for those water molecules to jump from the surface of the liquid—energy that they steal from the liquid itself, cooling it down , an open pot of stew in a degree oven will max out at around degrees. Good news for you, because that's right in the optimal sub-simmer stewing temperature zone. Pop the lid on, however, and you cut the amount of evaporation that takes place.
Less evaporation means higher max temperature. In my quick test at home, putting on the lid increased temperatures in the pot by almost 25 degrees! For this reason, I generally braise or stew with the lid to my pot slightly ajar. This allows enough evaporation to keep the temperature down, but not so much that the top surface of the stew dehydrates or browns. Pop quiz: I've got two identical pans. I then add a half ounce of water to each pan and time how long it takes for the water to evaporate.
You got it. In fact, when I performed this very test at home, it took nearly ten times as long for the water in the hot pan to vaporize. As a rule of thumb, simmer when you don't want what you are cooking to be jostled around poaching an egg , and use a rolling boil when you do to keep pasta separated.
Otherwise, don't worry. Add a comment. Active Oldest Votes. Improve this answer. So recipes are calling for 2 unless otherwise stated? Yes, that is correct. Remember that the "boiling point" the temperature at which water boils of water is significantly different based on altitude and mineral contents. Boiling an egg for 2 minutes in Colorado Springs yields a significantly different result than at the top of Pike's Peak. Sign up or log in Sign up using Google. Sign up using Facebook.
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