How long does it take for ice to freeze?

On a hot summer day, there is nothing better than a long drink filled with crystal clear ice cubes.

Most home freezers have some form of ice, and you may even be lucky enough to have an ice cube dispenser in your fridge.

But if you have forgotten to refill the ice cube trays, is there a way to freeze the ice quickly?

How long does it take for ice to freeze?

Ice takes 2-4 hours to freeze in a home freezer. Several factors affect the rate at which water turns from liquid to ice, including the surface of the cubes, the temperature of the freezer, and whether hot or cold water is used. The fastest way to freeze ice is to use pre-chilled water in a stainless steel tray with an air space between each cube.

Have you forgotten to fill the freezer with ice for a party? Or maybe you just need quick crushed ice for a cold dessert? Let’s find out everything you need to know about making ice at home!

How is ice made?

The act of turning liquid water into ice is an incredible miracle of science. For those of us whose school days are a dim and distant memory, let’s take a quick look at how this amazing process occurs.

In its liquid state, water is made up of molecules made up of two hydrogen atoms and one oxygen atom. These molecules move quickly, bouncing off each other. This maintains the fluid form of water that we all know.

When liquid water cools, the molecules slow down and start sticking together. At the freezing point (0°C/32°F) the molecules form a solid, which is what we know as ice.

When the ice is removed from the freezer, the molecules begin to move faster as they warm up. This causes the solid ice to turn back into a liquid, a process called thawing or melting.

So, that’s the science part! Now we go to the practical part.

To make ice at home, we need a container in which to place the water. This is usually a tray or bag with many compartments about the size of an ice cube. This maintains the shape of the water when it goes from a liquid to a solid.

As anyone who has tried to make ice in a hurry will tell you, this is not the fastest of processes. But how long does it take for ice to freeze and can we do anything to speed it up?

How long does it take for ice to freeze?

This is a question along the lines of “how long does a piece of rope last?” The time it takes for ice to freeze depends on many factors, such as

• Freezer temperature
• The size of the ice cubes
• The water’s temperature
• ice tray type

As a guide, it takes 3-4 hours for water to turn from liquid to ice in a standard home freezer, in a medium ice bucket.

However, there are so many variables that can alter this time scale that it makes more sense to examine each factor in more detail.

In fact, if we fully tune all potential variables, it is possible to make ice in just two hours! So if you’re in a hurry, check out our ultimate guide to making ice in a hurry.

Do different types of ice freeze at different rates?

The type of ice you make will affect the rate of freezing. When liquid water turns to ice, it freezes from the outside in. This means that the center of the cube is the last part to freeze.

The time it takes for the center to freeze lengthens as the size of the cube increases.

So if you want to freeze ice quickly, make small cubes! For this you can use a tray with smaller indentations, or fill your standard tray up to 1/3 of its capacity to obtain finer cubes.

A large block of ice takes the longest to freeze. Making a block of ice is quick to prepare, but it will take much longer to freeze than small ice cubes.

Conversely, small ice cubes thaw much faster than large ones. Have you ever dropped those tiny cubes into your drink, only to have them disappear in a matter of minutes?

Larger ice cubes will keep your drink cold longer, so if you have time to prepare them they may be a better option.

Does ice freeze at different rates in different containers?

The type of container you use can make a big difference in how quickly your ice cubes freeze. Not only the size of the ice cube influences, but also the shape and style of the ice cube tray.

If you’re in a hurry, use an ice tray that has an air space between each cube.

This increases the surface area available for cold air to reach and will give you a frozen cube much faster than a tray with dividers between each cube.

Speaking of surface area, the standard cube shape is actually the most inefficient when it comes to quick freezing.

Fun ice trays shaped like stars, flowers, and even animals will greatly increase the surface area of each cube, allowing them to freeze much faster.

Many of us use standard plastic and silicone trays to freeze ice as they are durable and strong. However, if you switch to a stainless steel tray you will get frozen ice much faster.

The only problem with stainless steel trays is that it can be difficult to remove frozen ice cubes when you’re ready to use them.

What is the best freezer temperature to freeze ice?

The standard temperature for most home freezers is 0°F. This is the optimum temperature for making ice, as well as for keeping your food perfectly frozen.

Temperatures colder than this cause freezer burn, so don’t be tempted to turn your freezer to the lowest temperature possible.

However, every time you open the freezer, the temperature will rise. It will then take time to return to 0 degrees, which will extend the time it takes for liquid water to turn into ice.

Ideally, you should avoid opening the freezer for three hours if you want to make ice quickly.

Another factor that affects the temperature of the freezer is its contents. If you put room temperature food in your freezer, this will temporarily increase the overall temperature of the freezer.

If you can, chill food in the fridge before putting it in the freezer.

Does ice freeze faster in an empty or full freezer?

Speaking of freezer contents, which is better, an empty or a full freezer?

Freezers that are kept fuller will maintain their temperature much more consistently. The frozen food mass will help to quickly return the freezer to optimal temperature as soon as the door is closed.

If the contents of your freezer seem a little short, you can “stock” your freezer with other items to fill the space and keep it running efficiently.

Use empty cardboard boxes to make large blocks of ice, which will help your freezer maintain the perfect temperature.

However, air must circulate inside the freezer, so don’t be tempted to overfill it. Always keep the freezer three-quarters full, but never to the brim.

To make ice quickly, place ice cube trays on top of already frozen food, if possible.

Does hot water freeze faster than cold?

This is a crazy but true fact: hot water freezes faster than cold! Named for a Tanzanian high school student, Erasto Mpemba, this phenomenon is called the Mpemba effect.

In the 1960s, Mpemba began to investigate how quickly different water temperatures froze.

His first observation was that when he made ice cream with hot milk, it would freeze faster than when he made it with cold milk. His teachers didn’t believe him, so he started doing his own experiments.

Amazed by this discovery, the scientists replicated Mpemba’s research. They discovered that, in many cases, hot water froze faster than cold water.

All because a young student refused to believe his teachers when they told him he was wrong!

But how does the Mpemba effect work and what is the optimal temperature for faster freezing?

Unfortunately, this is a hugely complex and slightly controversial topic! It’s not as simple as hot water freezing faster than cold, and other variables can affect how fast water freezes.

Scientists have yet to agree on why the Mpemna phenomenon occurs, but everyone agrees that it does!

If you’re tempted to try to make ice as fast as possible, you have two options when it comes to water temperature.

You have to start with water that is as cold as possible or at the boiling point.  Warm water will take longer to freeze than the previous two.

Ideally, use water from a jug stored in the refrigerator to make ice. If your tap water is ice cold, it can also be used to quickly make ice.

If you don’t have any of these options, try the boiling water trick. Just be careful not to spill hot water on yourself while filling the ice cube trays.

What is the best way to freeze ice quickly?

Have you forgotten to fill the ice cube trays for a big summer party? Don’t panic: if you follow these steps you can have ice ready to serve in just 2 hours.

Select the appropriate ice tray

Silicone and plastic ice trays are not as quick to freeze ice as stainless steel ones. If you don’t have this option, try a disposable plastic ice cube bag placed on a metal baking sheet.

If your only options are silicone or plastic trays, choose the ones with the smallest ice cube compartments, with an air space between each one. Fun shapes like stars and flowers will freeze faster than traditional ice cubes.

Check the freezer temperature

Your home freezer should be set at 0°F . Don’t be tempted to turn it any lower - you won’t speed up the ice’s curing rate much, and you may ruin all your carefully frozen food.

Use pre-chilled or hot boiling water

Warm water takes longer to freeze than boiling water. If you have cold water in the fridge, it will freeze faster.

Place the trays carefully in the freezer

Place your trays directly on a surface that is already frozen . If you use cold water, you can place the trays on top of frozen food.

Boiling water should be placed directly on a freezer shelf, to prevent accidental defrosting of your food.

Do not open the door

Close the door and walk away, for at least 2 hours. Opening the door earlier will only delay the freezing process.

Check the ice after 2 hours - hope you have perfect cubes! If not, leave it another 30 minutes and check again.

How to keep ice frozen

So you’ve gone to great lengths to have frozen ice for your summer barbecue or cocktail party.

But what a disappointment when those precious ice cubes quickly melt in the sun! Or what is worse, they stick together forming a huge and useless lump.

To prevent this from happening, you have to keep your ice cubes at the perfect temperature. There are some great ways to do it:

• Use a custom-made ice tray
• Use a cooler 
• Keep the ice in the fridge
• Put ice packs under your cubes

Then just put a handful of ice cubes in your glass, pour your drink of choice and enjoy! Health!

Related questions

Now that we’ve reviewed how long it takes to freeze ice, let’s look at some related questions!

How long do homemade popsicles take to freeze?

Making popsicles at home can be a fun and healthy way to make ice cream for the whole family. Best of all, you can make them in all your favorite flavors, so no more yucky lime pops that sit at the bottom of the freezer!

But how long do homemade popsicles take to freeze?  Homemade popsicles freeze between 4 and 8 hours. How long it takes depends on the amount and type of juice you use, as well as whether you’ve added any real fruit or sugar.

Can you use anything other than water to make ice cubes?

If you want fun and quirky ways to chill your drinks, you can make ice cubes out of many other things. Some of them can take longer to freeze than water, so remember to prepare them well in advance.

Other liquids that can be used to make ice cubes are lemonade, cola, coffee, fruit juice, and fruit smoothies.

You can also add solids to your ice cubes to make fun and tasty additions to your drink. Fruits, mint, cucumber, and even flowers can work great for this.

You just have to put them in an ice cube tray, pour them over the liquid of your choice and leave them for several hours in the freezer.

How is crushed ice made?

Crushed ice is a popular ingredient in many drink recipes, especially cocktails and iced coffee. But what is the best way to make crushed ice?

Crushed ice is made by taking standard ice cubes and breaking them into smaller pieces.

The best way to do this is to place the ice cubes inside a plastic bag or folded kitchen towel. You can speed up the process by first running hot water over the ice tray, which will help break up the cubes.

Place the ice in its bag or cloth on a solid surface, and use a firm object, such as a rolling pin, to tap the ice. Continue until the ice is the perfect consistency to turn your summer cocktail into a delicious slush drink. 

How is clear ice made?

Have you ever looked at the ice cubes in restaurants and coffee shops and wondered how they make them so clear and smooth? Ice made in home freezers tends to come out rough and cloudy, so what do they do differently?

Clear ice is made by making sure that the liquid water is completely free of air bubbles as it freezes.

You also have to make sure that the ice freezes from only one direction, so all sides of the tray except the top should be insulated. The best way to do this is to purchase an ice tray designed to make clear ice cubes.

Making clear ice consists of freezing the ice as slowly as possible, forcing air bubbles to the bottom of the tray. This is not a good method if you want to make ice quickly.