Does Salt Make Water Boil Faster? facts or Myths

logo by Editorial Staff | Updated on June 22nd, 2022

You’ve probably heard of chefs adding salt in a pot of water to speed up the boiling process. Is it true or is it simply a myth? Is it true that salt causes water to boil faster?


If you add enough salt to the water, it will boil faster. When salt is introduced to water, the water molecules find it more difficult to leave and enter the gas phase. As a result, the temperature of salt water rises quicker than that of pure water.

brown wooden spoon

There is a negligible difference in boiling time between salted water and pure water if a little quantity of salt is sprinkled into a pot of water. However, if you boil a gallon of 20 percent salt water in one pot and a gallon of clean water in another, the former will boil quicker.

Continue reading to discover more about boiling water with salt vs. boiling water without salt.

Is it true that salt causes water to boil faster?

Water will boil faster if you add salt, but you must use a lot of salt. The boiling point of salt water is greater. The temperature of salty water will rise quicker than the temperature of clean water.
There are several things that go into bringing a pot of water to a boil. These are their names:

  • The amount of heat or energy you put into the pot
  • The rate at which the temperature rises corresponds to the boiling point of the liquid when heated.
  • Pot A, for example, has a gallon of clean water, whereas Pot B holds a gallon of 20 percent salt water. If you have the ability to manage the burner and apply the same amount of energy to each pot, this is a negligible variable.

The Boiling Point

The boiling point of water, or any liquid, is the temperature at which it boils and converts to vapor.

When you add salt to a saucepan of clean water, the boiling point of the water rises. This rise, however, will only be between 4 and 216 degrees Fahrenheit. This amounts to a temperature of 2 degrees Celsius and a temperature of 102 degrees Celsius.

Remember that in order for the water to boil, the temperature must be 212 degrees Fahrenheit or 100 degrees Celsius. In that situation, the difference in time between boiling pure water and salt water is negligible.

The rise in boiling point is calculated using the ebullioscopic constant of water. This computation will result in a major variable. You will calculate the heat capacity of the solution and how quickly salt water or pure water warms up.

So, what is it about salt that causes water to boil faster? The presence of salt makes it more difficult for water molecules to escape and enter the gas phase. This will cause the water to heat up faster and so boil faster.

Capacity for Heat

The heat capacity of water is quite high. To put it another way, it takes a lot of energy to raise the temperature of water by even one degree Celsius.

To clarify, calories are the amount of energy required to heat one gram of water to one degree Celsius. To add another intriguing fact, it is important to understand that the water has a large heat capacity. It is especially true for a planet with two-thirds of its surface covered by water. This aids in global temperature regulation.

Is salt water hotter than pure water?

Examine the heat capacity of the salt water. It is less than that of pure water, as you shall discover. To summarize, increasing the temperature of salt water by one degree Celsius requires less energy than increasing the temperature of pure water. As a result, salt water can heat up faster since it reaches the boiling point first.

Salt water has a lesser heat capacity than pure water. Consider a pot containing 100 grams of clean water. The only item in the saucepan is clean water. In instance, a pot containing 100 grams of 20% salt water does not contain 100% pure water. Instead, it contains merely 80 grams of water. The remaining ingredients are all dissolved salt.

In comparison to the large heat capacity of water, the heat capacity of dissolved salt is zero. This just goes to prove that the heat capacity of the salt solution is only 80% that of pure water. The 20% salt water is projected to heat up around 25% faster than pure water. It goes without saying that it will reach the boiling point first.

If you fill two pots with 100 grams of clean water each and then add salt to one of them, the outcome will be different. The explanation for this is that the salted pot now has a larger capacity than the other pot.

What happens in a scientific sense when water boils?

To understand why certain approaches work and others do not, we must first go over some fundamentals of what happens on a molecular level when water boils.

Water exists in three states: solid (ice), liquid, and gas (water vapor).

Water slowly evaporates at ambient temperature, leaving its liquid form and entering the air as water vapor. This is why the floor dries after you sweep it or clothing hang to dry on a clothesline.

“Boiling is the fast evaporation of a liquid that occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid equals the pressure exerted on the liquid by the surrounding environment,” according to Wikipedia.

When a liquid is heated sufficiently, it reaches its boiling point, and evaporation transforms into vaporization. The surrounding atmosphere’s pressure has an effect.

It is worthwhile to take the time to properly boil your water. Boiling water correctly might lower your risks of contracting parasites and amoebas.

Most people, if not all, are aware of the old wives’ story that adding salt to a pot of water would cause it to boil quicker. Yes, as previously stated, there is a temporal difference between clean water and a salt solution.

If you add 3 grams of salt to 34 ounces of water and boil it, you won’t notice a difference when compared to pure water’s boiling time.

In order to bring water to a boil, both the vapor pressure and the air pressure must be equal. This explains why water at the summit of Mount Everest boils at a lower temperature than water at sea level. At 29,000 feet, the atmosphere or pressure is lower on the mountain.

Try boiling a saucepan of water at sea level with a pinch of salt. The presence of salt makes it more difficult for water molecules to reach the gas phase. This raises the boiling point of the salt solution.

Salt solution may boil quicker than pure water. To perceive the change, though, you would need to add a large amount of salt. In that example, if you’re cooking noodles and want them to boil faster, adding a lot of salt will just make them incredibly salty. As a result, trying this “experiment” is not suited for food.

How Can I Get Water to Boil Faster?

Do you really want the water to boil quicker than it should?

When cooking noodles, however, it is beneficial to add salt to the water. However, this is not to quickly boil water. It’s all about seasoning the noodles to make them tasty.

These are the steps she recommends for getting the water to boil:

  1. Always keep the pot covered.

Attempting to boil water in an open pot is akin to running backwards up a hill: you’ll get there eventually, but why struggle? Simply place a lid snugly on top and you’ll simply save a few minutes.

  1. Disperse

Increasing the surface area of the water by using a larger pot or pan exposes more of it to the hottest section of the pot, which is the bottom. It works well for thin veggies that can spread out in a pan, like as green beans, but it is not the ideal solution for things that require a deep pot, such as a head of cabbage.

  1. Use Less Water

Not everything you make will need a massive pot of water, not even pasta! Just be sure to stir it every now and then to keep the food moving.

  1. Use Your Kettle to Save Time

Using an electric kettle will help to speed up the boiling process. Boiling water in an electric kettle before putting it back into the pot to re-boil may appear inconvenient, but it’s a huge time saver.

  1. High-Altitude Cooking

This final suggestion isn’t very practical for those who live at sea level, but it’s still valuable to know. Water boils at 212°F at sea level, but as you ascend in elevation, the boiling point drops, lowering the time it takes to boil by a few minutes.

  1. Make use of a smaller pot

The smaller the amount of water, the faster it heats up. Use a tiny pot if you’re cooking something little.

Use a larger pot only when necessary. Similarly, only enough water should be added to cover the top of whatever meal you are cooking (unless the instructions indicate otherwise).

  1. Adding baking soda accelerates the boiling of water.

Baking soda is a wonderful ingredient. It has the ability to make cookies and cakes rise elegantly. It may also make your kitchen sparkle. However, contrary to popular belief, adding baking soda to water will not cause it to boil faster.

What You Should Know About Salt and Water

You’ve probably already learnt this in school. However, it is useful to be reminded of these facts. For example, when we consume water on a daily basis, do we recall what it is comprised of?

Let’s start with water’s chemical symbol: H2O. It is made of of hydrogen and oxygen in a 2:1 molar ratio. Needless to note, two hydrogen atoms are present for every oxygen atom in order to make water. The mass of an oxygen atom is roughly 16 times that of a hydrogen atom. The water molecule, on the other hand, is around nine-tenths oxygen by mass.

Water is solid at temperatures below 0 degrees Celsius. It is in its liquid condition when the temperature is between 0 and 100 degrees Celsius. A temperature greater than 100 degrees Celsius represents water in its gas form, commonly known as water vapor.

When we say water is polar, we imply that the oxygen atoms are somewhat negative due to the high density of electrons. It causes hydrogen atoms to be somewhat positive.

An ionic compound is table salt, which has the chemical symbol NaCl or sodium chloride. This indicates that the connection formed is the result of an electron provided by the sodium atom to the chloride atom. This differs from covalent bonding, in which electrons are shared.

The sodium-chloride bond is very electronegative. And the effects become clear when sodium chloride is dissolved in water.

What Is the Purpose of Adding Salt to Boiling Water?

What is the purpose of adding salt to boiling water? There are a few options for answering this typical culinary question.

Flavoring Water with Salt

Typically, salt is added to water before it is brought to a boil in order to cook rice or pasta. Adding salt to water gives the water taste, which is absorbed by the food. Salt improves the capacity of chemoreceptors on the tongue to identify chemicals recognized through taste. As you’ll see, this is the only valid justification.

Adding Salt to Water to Raise the Temperature

Another reason salt is added to water is because it raises the boiling point of the water, which means your water will be hotter when you add the pasta, allowing it to cook faster.

In theory, this is how it works. In actuality, adding 230 grains of table salt to a liter of water would only raise the boiling point by 2° C. For each liter or kilogram of water, this equates to 58 grams per half-degree Celsius. That is far more salt than anyone would want in their diet. We’re talking about salt levels that are saltier than the ocean.

Adding Salt to Water to Make It Boil Faster

Although adding salt to water raises its boiling point, it is worth mentioning that salted water boils faster. That may appear to be counter-intuitive, but you can simply test it for yourself.

Place two containers on a hot plate or burner to boil: one with clean water and the other with 20% salt in water. Why does salted water boil faster while having a higher boiling point?

It’s because the salt reduced the water’s heat capacity. The heat capacity is the amount of energy required to increase the temperature of water by one degree Celsius. Pure water has a tremendous heat capacity.

When you heat salt water, you’re creating a solution of a solute (salt, which has a very low heat capacity) in water.

Essentially, with a 20% salt solution, you lose so much heat resistance that the salted water boils significantly faster.

After Boiling, Add Salt

Some folks like to add salt to boiling water afterward. Because the salt is added after the fact, this obviously has no effect on the pace of boiling.

However, because the sodium and chloride ions in salt water have less time to react with the metal, it may help preserve metal pots against corrosion. The effect is small when compared to the harm you may cause to your pots and pans by leaving them for hours or days before washing them, so whether you add your salt at the beginning or finish isn’t a huge concern.

Why does adding salt to boiling water cause it to bubble more?

Have you ever added salt to nearly boiling water and immediately the pot filled with bubbles? You may believe that this demonstrates that salt causes water to boil quicker.

But what exactly is going on? Let’s get back to science.

When water boils, the individual molecules (which are made up of two hydrogen atoms and one oxygen atom) become agitated and move incredibly quickly.

The bubbles that develop are not made of air, but rather of pockets of water vapor ready to escape. These bubbles develop more quickly near nucleation sites, which have minor perturbations in the water.
These vapor bubbles may emerge as a result of a scrape on the inside of your pot or when you have a wooden spoon in the water.

Adding salt creates hundreds (if not thousands) of nucleation sites, making it easier for a large number of bubbles to develop.

But, just as using a scratched-up pot doesn’t make the water boil faster, so does adding salt.

Conclusion

Adding salt to water causes it to boil faster. When salt is added to water, it makes it more difficult for water molecules to leave and reach the gas phase, which occurs when water boils. The temperature of salt water will rise quicker than that of pure water, causing it to boil faster.

A sufficient amount of salt must be added to shorten the boiling time. There is a negligible difference in boiling time between salted water and clean water if you add a little of salt when cooking noodles. However, if you boil a gallon of 20 percent salt water in one pot and a gallon of clean water in another, the former will boil quicker.

When we see individuals adding salt to water when boiling noodles, it is not to help the water boil quicker. It’s mostly because they’re seasoning the noodles to make them more tasty.

There is some truth to the belief that salt causes water to boil quicker. However, a substantial amount of salt is required to do this. In that scenario, you wouldn’t want to prepare noodles with so much salt, would you?

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Editorial Staff

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