You have likely heard of chefs sprinkling salt in a pot of water to make it boil faster. Does it really work or just a myth? Does salt make water boil faster?
Salt does make water boil faster if you add enough salt to the water. When salt is added to water, it is harder for the water molecules to escape and enter the gas phase. For this reason, the temperature of salt water will get hotter faster than that of pure water.
If you sprinkle a tiny amount of salt into a pot of water, there is an insignificant change in boiling time between salted water and pure water. But when you boil a gallon of 20 percent salt water in a pot and a gallon of pure water in another pot at the same time, the former will boil faster.
Read on to learn more about boiling water with salt vs. without salt.
Does Salt Make Water Boil Faster?
Salt does make water boil faster, but you need to add a lot of salt. Salt water has a higher boiling point. The temperature of salted water will get hotter faster than that of pure water.
There are some factors involved in bringing a pot of water to a boil. They are as follows:
- Heat or energy level you put into the pot
- Speed of the temperature rising, corresponding to the heat input
- Liquid’s boiling point
For instance, pot A contains a gallon of pure water, and pot B contains a gallon of 20 percent salt water. If you have the power to control the stove and put the same energy level to each pot, this actually is an insignificant variable.
Boiling Point
The boiling point is the temperature, which water, or any liquid, boils and turns to vapor.
If you add salt to a pot of pure water, the water’s boiling point will indeed rise. However, this increase will only be between 4 degrees Fahrenheit and 216 degrees Fahrenheit. This translates to 2 degrees Celsius and 102 degrees Celsius.
Remember that the temperature has to be 212 degrees Fahrenheit or 100 degrees Celsius in order for the water to boil. In which case, the time difference between boiling pure water and salt water is indeed insignificant.
The ebullioscopic constant of water is used to calculate the increase in boiling point. This calculation will lead you to a significant variable. You will determine how fast salt water or pure water heats up and determine the solution’s heat capacity.
So why does salt make water boil faster? Salt makes it harder for water molecules to escape and enter the gas phase. This will increase the temperature of the water faster and therefore boil faster.
Heat Capacity
The water’s heat capacity is high. In other words, a whole lot of energy is needed to increase water temperature by even 1 degree Celsius.
Just to add information about calories, it means the amount of energy needed to heat a gram of water to 1 degree Celsius. To add another interesting piece of information, it is significant to know that the water’s high heat capacity is good. It is specifically true for a planet in which water covers two-thirds of its surface. This helps in the regulation of global temperature.
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Does Salt Water Boil Faster than Pure Water?
Try to observe the salt water’s heat capacity. You will learn that it is lesser than that of pure water. Suffice it to say that increasing the salt water temperature to 1 degree Celsius takes less energy than pure water. Therefore, salt water is capable of heating up faster as it reaches the boiling point first.
Compared to pure water, salt water has a lower heat capacity. Take a look at a pot filled with 100 grams of pure water. There is nothing else in the pot but pure water. In comparison, a pot filled with 100 grams of 20 percent salt water does not contain 100 percent pure water. Instead, it has 80 grams of water only. The rest are all dissolved salt.
Compared to the water’s high heat capacity, the dissolved salt’s heat capacity is zero. This only goes to show that the salt solution’s heat capacity equals only 80 percent of pure water. The 20 percent of salt water is expected to heat up approximately 25 percent quicker than pure water. Needless to say that it will reach the boiling point first.
Now, if you have two pots filled with 100 grams of pure water each and then add salt to one pot, the result will be different. The reason is that the salted pot will now have a greater volume than the other pot.
More on the Science Behind It
If not all, most people are aware of this old wive’s tale that putting salt into a pot of water will make the water boil faster. We have explained above that, yes, there is a time difference between pure water and a salt solution. In fact, Middlebury College Assistant Professor of Chemistry and Biochemistry, Lesley-Ann Giddings, can confirm this.
Giddings, when interviewed for LiveScience.com, was asked, “Does adding salt to water make it boil faster?” She said that there is truth to such an old wive’s tale. But she also added that the time difference is negligible. She said that if you add 3 grams of salt to 34 ounces of water and boil it, you would not even notice the difference if you compare it with the boiling time of pure water.
She explained that both the vapor pressure and the atmospheric pressure must be equal in order to bring water to a boil. This is why water on top of Mount Everest boils at a lower temperature than water at sea level. On the mountain, the atmosphere or the pressure is less at 29,000 feet.
Try boiling a pot of water at sea level and add a small amount of salt. The addition of salt will make it more difficult for the water molecules to enter the gas phase. This then gives the salt solution a higher boiling point.
Giddings also added that, yes, a salt solution might boil faster than pure water. However, you would have to add a significant amount of salt to notice the difference. In which case, if you are cooking noodles and you want it to boil faster, adding a lot of salt will only make your noodles terribly salty. So, trying this “experiment” is not at all suitable for foods.
How to Make Water Boil Faster?
Do you really want to boil water faster than it should? Television personality and businesswoman Martha Stewart might be able to help you.
As expected, Stewart also debunks myths about the power of salt to boil water fast. However, it is indeed good to add salt to the water when cooking noodles. But this is not to boil water fast. Instead, it is all about seasoning the noodles to make it flavorful.
According to her, these are what you need to do to get the water boiling:
- Keep the pot covered
- Increase the surface area
- Less water is enough
- You need the help of your kettle
- Cook in high altitudes
1. Keep the Pot Covered
You can boil water without covering the pot, but it will eat up a lot of your time. Putting the lid on will definitely save time and allow you to finish early.
As Stewart puts it, boiling water without the lid can be compared to running back up a hill. You know that you will get there, but it will take you longer than you should.
2. Increase the Surface Area
Use a wide pan or pot to increase the surface area. That way, the water is exposed and spread out at the bottom, which is the pot’s hottest area.
If you are boiling food, this works best for green beans and other thin vegetables. However, this is not ideal for vegetables like a cabbage head, which requires a deep pot.
3. Less Water Is Enough
There’s no need to fill the entire pot when boiling water for cooking. Remember that you are not only making the water boil fast. You also want to conserve water at the same time. In which case, use the right amount of water only.
Even when you are cooking pasta, you do not need to fill the entire pot of water. A half-filled pot of water is alright. You only have to make sure to stir the noodles occasionally.
4. You Need the Help of Your Kettle
There is this other myth that says cold water boils faster than hot. Well, the same thing with the myth about salt water – this myth is now debunked. It does seem obvious that when you boil hot water, it will indeed boil faster, right?
This shows that if you want to save time, use your electric kettle to boil the water first. Then, pour this boiled water into a pot of noodles — or vegetables or whatever you are boiling — to boil it again. You may find it cumbersome to boil boiled water, but I recommend this too.
Try it. Then, thank Martha Stewart later.
5. Cook in High Altitudes
If you are living at sea level, cooking at high altitudes is not very useful for you. Nonetheless, it’s good to be aware of this last tip.
Water boils at 100 degrees Celsius at sea level. To convert this to Fahrenheit, that is equivalent to 212 degrees. In terms of elevation, the higher you go, the lower the boiling point will be. This then decreases the boiling time for a few minutes.
Basic Information You Need to Know About Salt and Water
For sure, you have already learned this in school. However, it’s good to be reminded of these things. For instance, while we use water each and every single day, do we remember what it is made up of?
Let’s start with the chemical symbol of water: H2O. It consists of hydrogen and oxygen in a molar ratio of 2:1. Needless to say that for every oxygen atom, there are two hydrogen atoms present to form water. Oxygen is more massive than a hydrogen atom by approximately 16 times. But the water molecule is roughly nine-tenths oxygen by mass.
At temperatures below 0 degrees Celsius, water is solid. If the temperature is at 0 to 100 degrees Celsius, it is at its liquid state. A temperature that exceeds 100 degrees Celsius is water at its gas state, or what is also known as water vapor.
When we say water is polar, this means that oxygen atoms are slightly negative due to the electrons’ high density. It leaves hydrogen atoms in a slightly positive state.
Table salt, the chemical symbol of which is NaCl or sodium chloride, is referred to as an ionic compound. This means that the bond it forms is an outcome of an electron from the sodium atom donated to the chloride atom. This is different from covalent bonds, wherein electron sharing occurs.
The bond between sodium and chloride is highly electronegative. And the consequences become evident when you dissolve sodium chloride in water.
Conclusion – Does Adding Salt to Water Make It Boil Faster?
Adding salt to water does make it boil faster. When salt is added to water, it is harder for the water molecules to escape and enter the gas phase – which happens when water boils. The temperature of salt water will get hotter faster than that of pure water and therefore boil faster.
There needs to be enough salt added to speed up the boiling time. If you sprinkle a bit of salt when cooking noodles, there is an insignificant change in boiling time between salted water and pure water. But when you boil a gallon of 20 percent salt water in a pot and a gallon of pure water in another pot at the same time, the former will boil faster.
If we see people adding salt to water when boiling noodles, it is not because they want to make the water boil faster. It is mainly because they are seasoning the noodles to make it flavorful.
Somehow, there is a truth behind the myth that salt makes water boil faster. However, you need to add a significant amount of salt to make that happen. In which case, you would not want to cook noodles with so much salt in it, right?
So, if you want to make the water boil fast, you might want to take note of Martha Stewart’s tips instead of relying on salt.
Here are her tips:
- Keep the pot covered
- Increase the surface area
- Less water is enough
- You need the help of your kettle
- Cook in high altitudes
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