The Boiling Point
FOOD FOR THOUGHT - September 13, 2006
Mark R. Vogel - [email protected] - Archive of other articles by Mark Vogel
One summer day a few years back I was barbecuing for some friends. As I grilled the steaks in the backyard, inside on the stove I was boiling the marinade they had marinated in. I intended to utilize the marinade as a sauce and since the raw meat had rested in it, it needed to be boiled to kill any harmful bacteria. A secondary function of boiling it was to reduce it and thus intensify its flavor. One of my friends, who had passed through the kitchen on her way back from the lavatory announced: “Your pot was boiling so I turned it down.”
Similarly, one night I was preparing for one of the cooking classes I teach. I was boiling balsamic vinegar to reduce it to a syrupy glaze for a shrimp hors d’oeuvre. I stepped away to get a cup of coffee when a gentleman approached me stating: “Something was boiling on your stove so I turned it off.” His unsolicited meddling brought me to the verge of my own boiling point. I wanted to sharply tell him to mind his own business but instead I explained that my concoction was supposed to be boiling. Two things prevented me from boiling over. First, I knew he meant well. Second, like my barbecue guest, he suffered from Boiling-Overreaction-Disorder which runs rampant in the culinarily ignorant. It’s a syndrome characterized by a heightened sensitivity to liquids at or near the boiling point. Typically it triggers a frenzied attempt to reduce or cease the boiling reaction. It has only one known cure: Education. Some studies have reported that exposing individuals to factual knowledge about boiling can reduce their irrational ideas about it, and hence desensitize them to vaporizing vessels of liquid.
Boiling is the process by which water is heated to the point that the energy it has absorbed causes the molecules to break free and dissipate into the surrounding air. In a word, it vaporizes. The boiling point of water is 212 degrees Fahrenheit at sea level and decreases with altitude. Water molecules must overcome atmospheric pressure to escape their liquid state. The lower your altitude, the more amount of atmosphere bearing down on you, and hence the higher temperature required to boil the water. On top of Mt. Whitney, the highest peak in the continental US at nearly 15,000 feet, water will boil at approximately 184 degrees.
Boiling is a wet heat cooking method whereby food is cooked, i.e., imbibed with heat, via conduction, (from contact with the water molecules) and convection (from the movement of the water molecules).
The rate of energy transmission in boiling is significant. Because water is denser than air, foods will cook faster in boiling water than in an oven.
Boiling must be distinguished from simmering and poaching; two other wet heat cooking methods. The difference between poaching, simmering, and boiling is the temperature of the fluid medium. Poaching is from 160 to 185 degrees, simmering is beyond 185, and boiling is when you obviously achieve a full boil. These temperature differences are not arbitrary and have significant ramifications for the food being cooked. The hotter the liquid, the more destructive it’s force, not only from the higher temperature but from the increased turbulence as well. You would never put a fragile piece of fish into boiling water. The heat and agitation would disintegrate it.
Because of the disintegrating nature of boiling, it is more appropriate for very hard foods, the quintessential example being pasta. Dried beans, potatoes and most root vegetables can also be boiled. Many foods requiring submersion in liquid however, are brought to a boil and then reduced and maintained at a simmer. All of the aforementioned foods, with the exception of pasta, can be cooked this manner. Pasta must remain at a constant boil. Nutritional opponents to boiling argue that it leaches too many nutrients and prefer simmering or poaching to boiling. Boiling can also dissolve many flavor components as well.
In blanching, gentler foods are boiled but only briefly. Blanching is used for vegetables to maintain their color, soften them, to remove their skin, or eliminate bitter flavors. Blanched vegetables are usually “shocked” in ice water after boiling to prevent carry over cooking. Whether boiling or blanching always salt the water beforehand to facilitate the seasoning of the food. And always use a large pot with ample amounts of water. The more water, the less its temperature will drop when you add the food and the more you will be actually boiling and not simmering or poaching.
Finally, boiling can be used to reduce liquids in order to thicken them, intensify their flavors, or sterilize them as in my introductory examples. Alcohol is brought to a boil when deglazing a pan, sauces are boiled to concentrate them and marinades that have had contact with raw meat, as stated, must be boiled if you desire to employ them as a sauce.
So there you have it; numerous examples where boiling is no cause for alarm, and in fact, may be absolutely necessary depending on the task at hand. Hopefully I’ve cured you of your anti-boiling impulses and prevented you from turning off some other poor chef’s pot.