1. to change from a liquid to a gaseous state, producing bubbles of gas that rise to the surface of the liquid, agitating it as they rise.
2. to reach or be brought to the boiling point: When the water boils, add the meat and cabbage.
3. to be in an agitated or violent state: The sea boiled in the storm.
4. to be deeply stirred or upset.
5. to contain, or be contained in, a liquid that boils: The kettle is boiling. The vegetables are boiling.
6. to cause to boil or to bring to the boiling point: Boil two cups of water.
7. to cook (something) in boiling water: to boil eggs.
8. to separate (sugar, salt, etc.) from a solution containing it by boiling off the liquid.
Water is boiled for two purposes: first, cooking of itself to destroy organic impurities; second, for cooking foods. Boiling water toughens and hardens albumen in eggs; toughens fibrin and dissolves tissues in meat; bursts starch grains and softens cellulose in cereals and vegetables. Milk should never be allowed to boil. At boiling temperature (214° F.) the casein is slightly hardened, and the fat is rendered more difficult of digestion. Milk heated over boiling water, as in a double boiler, is called scalded milk, and reaches a temperature of 196° F. When foods are cooked over hot water the process is called steaming.
Boiling for water sterilization
Boiling can be used as a method of water disinfection but is only advocated as an emergency water treatment method, or as a method of portable water purification in rural or wilderness settings without access to a potable water infrastructure. Bringing water to the boil is effective in killing or inactivating most bacteria, viruses and pathogens. Boiling is the most certain way of killing all microorganisms. According to the Wilderness Medical Society, water temperatures above 160° F (70° C) kill all pathogens within 30 minutes and above 185° F (85° C) within a few minutes. So in the time it takes for the water to reach the boiling point (212° F or 100° C) from 160° F (70° C), all pathogens will be killed, even at high altitude. To be extra safe, let the water boil rapidly for one minute, especially at higher altitudes since water boils at a lower temperature.
Boiling in cooking
In
cooking, boiling is the method of cooking food in heated water, or
other water-based liquid such as stock or milk. Simmering is gentle
boiling, while in poaching the cooking liquid moves but scarcely
bubbles.
Boiling
is a very harsh technique of cooking. Delicate foods such as fish
cannot be cooked in this fashion because the bubbles can damage the
food. Foods such as red meat, chicken, and root vegetables can be cooked
with this technique because of their tough texture.
The boiling point of water is typically considered to be 100 °C or 212 °F. Pressure and a change in composition of the liquid may alter the boiling point of the liquid. For this reason, high elevation cooking generally takes longer since boiling point is a function of atmospheric pressure. In Denver, Colorado, which is at an elevation of about one mile, water boils at approximately 95 °C. Depending on the type of food and the elevation, the boiling water may not be hot enough to cook the food properly. Similarly, increasing the pressure as in a pressure cooker raises the temperature of the contents above the open air boiling point.
Adding a water soluble substance, such as salt or sugar also increases the boiling point. This is called boiling-point elevation. However, the effect is very small, and the boiling point will be increased by an insignificant amount. Due to variations in composition and pressure, the boiling point of water is almost never exactly 100 °C, but rather close enough for cooking.
Bringing water to a boil is generally done by applying maximal heat, then shutting off when the water has come to a boil, which is known as bang–bang control. Keeping water at or below a boil requires more careful control of temperature, particularly by using feedback.
In places where the available water supply is contaminated with disease-causing bacteria, boiling water and allowing it to cool before drinking it is practiced as a valuable health measure. Boiling is the most certain way of killing all microorganisms in emergency situations.
Foods suitable for boiling include vegetables, starchy foods such as rice, noodles and potatoes, eggs, meats, sauces, stocks and soups.
Boiling has several advantages. It is safe and simple, and it is appropriate for large-scale cookery. Older, tougher, cheaper cuts of meat and poultry can be made digestible. Nutritious, well flavored stock is produced. Also, maximum color and nutritive value is retained when cooking green vegetables, provided boiling time is kept to the minimum.
On the other hand, there are several disadvantages. There is a loss of soluble vitamins from foods to the water (if the water is discarded), and some boiled foods can look unattractive. Boiling can also be a slow method of cooking food.
Boiling
can be done in several ways: The food can be placed into already
rapidly boiling water and left to cook, the heat can be turned down and
the food can be simmered; or the food can also be placed into the pot,
and cold water may be added to the pot. This may then be boiled until
the food is satisfactory.
Water on the outside of a pot, i.e. a wet pot, increases the time it takes the pot of water to boil. The pot will heat at a normal rate once all excess water on the outside of the pot evaporates.
How To Boil
Boiling water is very easy to do, but it is crucial to many meals, such as cooking rice and Pasta. You just heat the water until it starts bubbling. But there’s a little bit more to it than that…
Know what kind of boil you’re going for:
Poaching, simmering, and boiling are slightly different techniques. Boiling is when the water gets as hot as it’s going to get and begins to evaporate into steam.
Choose a pot that’s large enough to hold the amount of water you want to boil, and has a lid that fits.
You might be tempted to use water that’s already warm or hot from the tap, but this water has been sitting in your pipes for some time, getting stale. Use cold water if you’re going to drink it or cook with it.
Don’t fill the pot all the way up. Keep in mind that anything you add to the boiling water will increase the volume, and plus, you’ll need to allow room for those bubbles to do their thing. Without enough room in the pot, for example, rice or pasta will boil over.
Place the pot on the stove and turn the heat to high. If you want to speed up the process, put a cover on it.
Add salt only for seasoning. There’s a myth that adding salt will make the water boil faster. Adding salt raises the boiling point, which means the water will need to be hotter to begin boiling, therefore actually taking longer to boil.
Check for steam escaping from under the lid, then lift the lid carefully to see how the water is doing.
Water boils at 212° F. (sea level), and simmers at 185° F. Slowly boiling water has the same temperature as rapidly boiling water, consequently is able to do the same work. Once the water has reached boiling temperature, Turn down the heat. Keeping the heat on high won’t make a difference in temperature.
Look at the water. If large bubbles are rising from the bottom of the pot to the surface, the water is boiling. TIP: Small bubbles that stay at the bottom or sides of the pot are air bubbles present in the water; they don’t necessarily indicate that boiling is imminent. Wait for bubbles that rise to the top of the pot.
High Altitudes:
Water will boil at high altitudes, but it isn’t as hot as boiling water at sea level. This is because the air pressure is lower at high elevations. Boiling occurs when the water is hot enough to have the same pressure as the surrounding air, so that it can form bubbles. At high altitudes, air pressure is lower than at sea level, so the water doesn’t have to get so hot to get to boiling.
TIP: Because the temperature of the boiling water is lower at high elevations than at sea level, it takes longer to cook at higher altitudes than at sea level. The speed that food cooks is not related to the time it takes to boil.
Adding a little salt to the water will cause the water to boil at a slightly higher temperature which can be helpful while cooking especially at high altitudes.
Boiling water in the microwave is pretty straightforward, but there is the risk of super heating, when the water heats up past the boiling point without bubbling and then erupts suddenly, possibly causing burns. While this is unlikely there are some precautions you can take.
Microwave
Put the water in a microwave-safe cup or bowl. For increased safety, use a container that has a scratch or chip (in scientific terms, a nucleation site) on the interior surface. This will help the water bubble.
Place a non-metallic object such as a wooden spoon, chopstick, or Popsicle stick in the water. This also helps the water bubble.
Put the water in the microwave. Heat in short intervals, stirring regularly, until the water is steaming. (Even if these steps are followed, bubbling won’t be obvious.)
Stir the liquid thoroughly to add a little air to the mix, before heating.
Tips
• If
you are boiling something other than water, such as sauce, turn it down
as it reaches boiling to avoid scorching the bottom to the pot.
• If a recipe calls for something to be at a “full, rolling boil” it means that the water should not stop boiling when you stir.
• Hot water boils faster than cold water.
Warnings
• Boiling water and the steam coming off of it are hot enough to burn you. Use a pot holder if you need to, and handle with care.
• Steam will scald more than boiling water due to the extra heat energy it contains.
• Watch out if heating distilled water in a microwave as it can explode when picked up. (flash boil)
References