How long does it take water to freeze? I was having some family come over to my place the other day and needed ice for drinks. I kept checking the ice cube tray to see if it was frozen yet (which wasn’t smart as that let warm air in). It made me want to find out exactly how long does it take water to freeze?
How long does it take for water to freeze into ice? It takes about 3 to 4 hours for a standard ice cube tray of water to freeze. This is in a standard freezer with a temperature of 0° F (-18° C).
If you fill-up the 12 or so spaces in the ice tray with water at room temperature and place it in the freezer, it will take three to four hours before the water freezes. It will take less time to freeze if you use a smaller container, a metal container, or a colder freezer.
That is the average time for water to freeze in a standard ice cube tray and standard refrigerator, but the time will vary in other scenarios. Freezing water is not a simple process as you may think. The speed (by which water freezes) depends on the amount of water to freeze, the capacity and power of the freezer, and the container you are using.
Read on to learn more about how long it takes water to freeze. Then you’ll know exactly when the ice cubes will be ready for your party!
How Long Does It Take Water to Freeze?
First, let’s look at the time it takes for water to freeze into ice cubes. Then we will look at the time it takes for water to freeze in a dedicated ice maker and a water bottle.
How Long Does It Take a Standard Ice Cube Tray Filled with Water to Freeze in a Standard Freezer?
In most cases where a standard home freezer is used, it will take approximately three to four hours to freeze ice cubes. This is the average time to freeze water placed in a standard ice cube tray with 12 square spaces.
Water freezes at 0°C or 32°F. However, the actual freezing time will depend on a number of factors. Your freezing time may be different from your neighbor’s because of these factors.
Size of Container
One factor that will affect the freezing time is the size of the ice cube tray. Most ice cube trays are formed with 12 tapered cubes. If the sizes of the cubes are small, your freezing time will, of course, be shorter. But if they are larger, the water inside them will take a longer time to freeze.
Design of Container
The design of the ice tray will also affect the freezing time. There are ice trays where the tapered cubes are separated only by dividers, and there are ice trays where there are air spaces between the empty cubes.
The water’s surface area in the first design is less than the water’s surface area in the second design. There are air spaces between the cubes in the second design, whereas the first design only has dividers to separate the cubes from each other.
This makes the surface area of the water in the second design larger than the first design. Ice begins to form from the outside-in. Therefore, the larger the surface area of the water that is exposed to the cold temperature, the faster it will freeze.
The third factor is the temperature inside your freezer. The standard setting of home freezers is 0°F or (-) 18°C. But if you habitually open your freezer, or fill it with food at room temperature while you are making ice, the temperature inside the freezer will go up. This will slow down the time to freeze the water inside the ice cube tray.
Time It Takes Water to Freeze in a Dedicated Ice Maker
Dedicated ice makers for the home are similar to commercial ice machines, but they are smaller. They are commonly called countertop ice makers. These machines can freeze water faster than the average freezers inside home refrigerators.
It can take only two hours to freeze water in a dedicated ice maker. This is the time it would generally take for room temperature water to freeze into standard-sized ice cubes.
There is a metal tray inside an ice maker which is connected to compressor coils. The compressor pumps the refrigerant, which is transported by the coils directly to the metal tray. This is called direct freezing, which is the same process that big ice makers use.
But instead of the tray being filled with water, the dedicated ice maker has water running over the tray. Remember, the tray is already extremely cool. In this way, ice crystals form rapidly on the tray. These ice crystals continue to build up as the water continues to flow over the tray. Water freezes up much faster, almost instantly, compared to the freezer of a home fridge which requires hours to do the same work.
There is also a bonus if you will use a dedicated ice maker for the home. You will really get crystal clear ice because it won’t have any impurities. They are the best for cold drinks and cocktails. Ice crystals start forming from the outside in. Thus, the gases and minerals in the water are pushed toward the center of the tray.
In a regular freezer, they will form an unattractive white cloud at the center of the ice. In a dedicated ice maker, you won’t have that white cloud at the center because of the action of the cascading water. The cascading water will not allow the impurities to be trapped at the center of the ice. What you will get is crystal clear ice every time.
How Long Will It Take a Bottle of Water to Freeze Using a Standard Freezer?
The time it takes for a standard 16-ounce plastic bottle of room-temperature water to freeze in a standard freezer is 1.5 hours. A lot will depend on the size of the bottle. Naturally, the smaller the bottle, the faster the water inside it will freeze.
If you use a standard home freezer, the water inside a small 8-ounce plastic bottle of water will take about 30 minutes to freeze, while the water inside a 1-liter plastic bottle of water will take about 2 hours to freeze.
How to Make Water Freeze Faster
If you need ice fast, like for a party or maybe a hot day, here’s what you need to do. Even if it takes water to freeze at an average time of 3 to 4 hours, you can speed up the process. Actually, there are six ways you can do it faster.
Freeze in a Plastic Bottle
Freeze water quickly by following these steps:
Lower the temperature setting of your freezer. Change it from -24°C to -11°C. It can take about an hour or more for the freezer to drop below 11°C.
Fill plastic bottles and place them inside the freezer. Wait for at least 2 hours and 45 minutes. The water inside the bottles shouldn’t freeze yet. If it is frozen, the temperature controller of your freezer is defective, which is a common issue with old freezers.
Remove the water bottles from the freezer. Be sure to do it smoothly, or you will defeat the process.
Give one bottle a strong tap or jolt on its side and see the water inside instantly freeze.
Do the same to the other bottles. If you want to use the ice, you have to break or cut up the plastic bottles. You should have cylindrical ice cubes that you can use for whatever purpose you like.
Use a Cookie Sheet
Water in a tray or a cookie sheet will freeze faster than water in a plastic bottle. The reason is that the surface area in the tray is greater than the surface area in the bottle. More surface area of water in the tray is in contact with the cool temperature than in the plastic bottle. That makes the water freeze faster.
Use Bottled or Distilled Water
Don’t use tap water. Tap water contains many impurities that affect the crystallization of the water molecules. Distilled water and bottled water has fewer impurities; therefore, they will freeze faster.
Use Metal Trays
Metal trays are better for freezing water because they conduct heat better than plastic trays. If you can afford it, use copper trays. Copper removes heat faster than other types of metal.
Pre-chill the Ice Cube Trays
Put empty metal ice cube trays in your freezer. Once you are ready to make ice, take them out and fill them with water. Then put them back in the freezer. The cold surface of the ice cube trays will speed up the freezing of the water.
Boil Water then Freeze It
There is scientific evidence that boiled water freezes faster than water at room temperature. They call it the Mpemba Effect.  This is still under scientific debate. However, some have forwarded five theories that may cause boiled water to freeze faster. These theories are:
Convection currents arise because water on the sides of the container and the top surface cools down, causing it to sink. When that happens, warm water rises to take the place of the cooled water. In warm containers, the convection currents are bigger. That has an effect on cooling rates.
More water molecules are lost in a container filled with boiled water through evaporation; therefore, there is less water to freeze.
Water’s freezing point is zero degrees celsius. But there are times when water gets colder before it freezes. This is called supercooling. This happens because ice requires a nucleation site like an air bubble for it to begin to form. Possibly, there is less supercooling in warm water than in cold water.
Dissolved gases are greater in cold water than in warm water. Some researchers believe that this situation can affect cooling rates. But how this happens is not yet clear to them.
Frost acts as an insulator. This could be the reason why frosty cold water retains heat better than a warm container that melts the frost on its sides.
Speed Up the Freezing Time with Your Standard Freezer
You can speed up the time it takes to freeze water by using these three methods. Special equipment is not required for this experiment but just your home freezer. Get some bottled water, preferably distilled, for greater effect.
Step 1: Place the bottled water inside the freezer. Leave it there for 2 hours and 45 minutes.
Step 2: Take the water bottle out of the freezer. The water inside the bottle is still in liquid form but is already well below freezing.
Step 3: Take some ice crystals and place them inside a small bowl. Remove the cap from the bottled water and pour the supercooled water onto the ice crystals. You will see that the water you pour into the ice immediately turns into ice. You can actually form nice ice sculptures using this method.
Step 1: Repeat steps 1 and 2 of Method A.
Step 2: Take an empty glass of water and pour the supercooled water from the bottle into it.
Step 3: Drop an ice crystal inside the glass of water and see that the liquid turns to ice instantly.
Step 1: Repeat steps 1 and 2 of Method A
Step 2: Take an empty cup and pour the supercooled water into it.
Step 3: Take a piece of ice crystal and stick it just on top of the water’s surface and see the water turn instantly into solid ice.
Can You Freeze Water Fast in a Home Freezer?
Yes, you can use your ordinary home freezer to freeze water fast. Here’s how you can do it.
Pour water into a bottle.
Remove some of the ice that formed in your freezer and get some rock salt and mix them in a big bowl.
Put the bottled water inside the bowl and let it sit there for about 30 minutes or so. Rock salt lowers the freezing/melting point of ice. This enables water inside the bottle to get a ‘boost’ and causes it to freeze faster than usual.
Don’t worry if you don’t have enough ice for your party tonight. It doesn’t really take that long for water to freeze if you follow the tips in this article.
Conclusion – How Long Does It Take for Ice to Freeze
So to recap, how long does it take ice to freeze? How long does it take for ice cubes to freeze? It takes about 3 to 4 hours for the ice to freeze in a standard ice cube tray of water. This is in a standard freezer with a temperature of 0° F (-18° C).
If you fill-up the spaces in the ice cube tray with water at room temperature and place it in the freezer, it will take approximately three to four hours before the water freezes. It will take less time to freeze if you use a metal container, a smaller container, or a freezer with a colder temperature.
Water in a standard water bottle will freeze in about 1.5 hours. This is for a standard 16-ounce plastic bottle of room-temperature water in a standard freezer.