#AtoZChallenge: Cooking Terms – B is for Boiling

Click on letter to go to the A-Z Challenge site
Click on letter to go to the A-Z Challenge site

To boil means to cook food in liquid at a temperature that causes bubbles to form in the liquid and rise to the top, breaking at the surface.  This usually occurs at about 212 degrees Fahrenheit/100 degrees Celsius

Boiling water is a very easy process:
  • First, choose a pot that’s large enough to hold the amount of water you want to boil.
  • Make sure you leave enough room for the fact that boiling water will increase the volume.  You’ll need room for the bubbling action.
  • While tempting to use water that’s already warm or hot from the tap, the best is to start with cold water.
  • Place the pot on the stove and turn the heat to high (you can speed up the boiling process by putting a lid on the pot

Contrary to how it might seem, a watched pot takes no more or less time to boil than an unwatched one.  It just seems to take longer since you are concentrating on it – The saying goes “time flies when you’re having fun”,  More accurate (IMO) is that time seems to go by faster when you are doing something engaging.  Standing around staring at a pot of water is NOT engaging.

Before we start boiling, however, let’s look at the stages leading up to a full rolling boil

  • Tepid Water – About same as that of body.  85 to 105°F.
  • Warm Water – About same as a nice hot relaxing bath.  115 to 120°F
  • Hot Water – At this point you can no longer hold finger in.  130 to 135°F
  • Poach – . The water is beginning to move, “to shiver”.  160 to 180°F
  • Simmer – At this point tiny bubbles will form on the bottom.  185 to 200°F
  • Slow boil – Bubbles will be larger and rising up to the top 205°F.
  • Rolling Boil – Water is rolling, and bubbles are breaking at surface.  212°F.

There is a misconception that simmering and slow boil are at the same temperature as a rolling boil however, as you can see, this is not the case.  Only a full rolling boil is approximately 212 degrees

Another misconception is that adding salt will lower the temperature at which water boils or make it boil quicker.  In fact salt actually increases the  boiling point of water and in reality you would need quite a large amount to make any difference more than you would want for edible cooking

The boiling point of a liquid is the temperature at which its vapor pressure is equal to the pressure of the gas above it.

So why do I say approximately 212 degrees?

There are many factors that come into play when  it comes to boiling water.  One  of the biggest is Altitude or Elevation.

Water will boil at a lower temperature at higher altitudes, due to  the fact that air pressure is lower at high elevations.  An approximate rule of thumb is that for each 500 foot increase in altitude there is a drop of about 1° in the boiling point.



Sea Level

212 degrees F

984 ft.

210 degrees F

2,000 ft.

208 degrees F

3,000 ft.

206 degrees F

5,000 ft.

203 degrees F

7,500 ft.

198 degrees F

10,000 ft.

194 degrees F

20,000 ft.

178 degrees F

26,000 ft.

168 degrees F

As you can see, the higher you go the lower the temperature is that water will  boil at and vice-verse.  However, unless there is huge difference in 2 elevations there will not be a noticeable difference in temps.  Note that at sea level water boils at 212 and at 984 ft it only goes down to 210.    At 2000 ft it only goes down to 208 that’s only a total of 4 degrees difference.

The type of molecules that make up a liquid can also affect the boiling point.  If the intermolecular forces between molecules are relatively strong, the boiling point will be relatively high.  If they are weak, the boiling point will be relatively low.

Adding salt or other water soluble substance (like sugar)

For you “Science” types  here is a macroscopic view of what happens when water boils

As a liquid is heated, its vapor pressure increases until the vapor pressure equals the pressure of the gas above it.

Bubbles of vaporized liquid (i.e., gas) form within the bulk liquid and then rise to the surface where they burst and release the gas. (At the boiling temperature the vapor inside a bubble has enough pressure to keep the bubble from collapsing.)

In order to form vapor, the molecules of the liquid must overcome the forces of attraction between them.

The temperature of a boiling liquid remains constant, even when more heat is added.

Uses for boiling

When it comes to cooking there are several advantages.  For one it can make older, tougher, cheaper cuts of meat & poultry more digestible and palatable. By boiling vegetables you can can a broth rich with nutrients (infact we do that very thing in our household using parts of the vegetables that might otherwise be tossed in the trash – you can read about that on my family blog here).  Foods that are  suitable for boiling would include vegetables, starchy foods (such as rice, noodles and potatoes), eggs, meats, sauces, stocks and soups.

Besides being useful for cooking, boiling water is also useful as a method of disinfecting water.  Bringing water to its boiling point (remember we’re talking full rolling boil here) is one of the oldest and most effective way to disinfect and make water potable.   One problem with this is that It does tend to loose it’s good taste.  However, this can be fixed by reintroducing air into the water (it’s the loss of air during the boiling process that causes the loss of flavor).  By partly filling a jar or bottle and shaking vigorously or by using an egg beater or whisk you can reintroduce the air and improve the flavor a bit.


Join me on an A to Z Journey of Cooking Terms throughout the month of April.


5 thoughts on “#AtoZChallenge: Cooking Terms – B is for Boiling

  1. Wow Tena! What an amazingly detailed post! I never realised that about adding air back into boiled water to improve the taste! 🙂 Thank you! Interested to see how your A-Z will continue… glad I’m not trying to think up cooking methods for Q, Z, V, or many others!!! 🙂 Life Doet Health (A-Z 674 atow)

    Liked by 1 person

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