On a hot summer’s day, nothing beats a long drink filled with crystal-clear ice cubes!
Most home freezer compartments will have some form of ice in them, and you might even be lucky enough to have an ice-cube dispenser in your refrigerator.
But what if you’ve forgotten to refill your ice cube trays – is there any way to freeze ice quickly?
How long does it take for ice to freeze? Ice will take between 2-4 hours to freeze in a domestic freezer. Several factors will affect the speed at which water turns from liquid to ice, including the surface area of the ice cubes, freezer temperature, and whether hot or cold water is used. The quickest way to freeze ice is to use pre-chilled water in a stainless-steel tray with an air space between each individual ice cube.
Forgotten to fill your freezer with ice ready for a party? Or maybe you just need some quickly crushed ice for a chilled 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 have a quick recap of how this amazing process happens.
In its liquid state, water is made up of molecules formed from two hydrogen atoms and one oxygen atom. These molecules move around quickly, bouncing off each other. This maintains the fluid form of water that we are all familiar with.
As liquid water is cooled down, the molecules slow down and start to stick together. At freezing point (0°C/32°F) the molecules form a solid, which is what we know of as ice.
When ice is removed from the freezer, the molecules will start to move faster as they warm up. This turns the solid ice back into a liquid, a process called thawing or melting.
So, that’s the science bit! Now for the practical part.
To make ice at home, we need a container in which to place water. This is normally a tray or bag with lots of ice-cube sized compartments. This holds the shape of the water as it turns from a liquid to a solid.
As anyone who has tried to make ice in a hurry will tell you, this isn’t 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 bit of a ‘how long is a piece of string’ kind of question! The time it takes for ice to freeze depends on many factors, such as:
- Freezer temperature
- Size of ice cubes
- Water temperature
- Type of ice cube tray
As a rough guide, it would take 3-4 hours for water to turn from a liquid to ice in a standard home freezer, in an average ice cube tray.
However, there are so many variables that can alter this timescale, that it makes more sense to look at each factor in more detail.
In fact, if we completely fine-tune all the potential variables, it is possible to make ice in just two hours! So, if you’re in a rush, take a look at our ultimate guide to making ice in a hurry.
Do Different Types Of Ice Freeze At Different Speeds?
The type of ice you are making will affect the speed at which it freezes. When liquid water turns to ice, it freezes from the outside inwards. This means that the very center of the ice cube is the last part to freeze.
The time it takes for the middle to freeze gets longer as the size of the ice cube increases.
So, if you want to freeze ice quickly, make small ice cubes! To do this you can use a tray with smaller indentations, or alternatively, fill your standard tray to 1/3 full to get thinner ice cubes.
A large block of ice will take the longest time of all to freeze. Making a block of ice is quick to set up, but will take far longer to freeze than tiny ice cubes.
Conversely, small ice cubes thaw a lot faster than large ones. Have you ever popped those dinky little cubes in your drink, only for them to disappear in minutes?
Larger ice cubes will keep your drink chilled for longer, so if you have the time to make them they may be a better option.
Does Ice Freeze At Different Speeds In Different Containers?
The type of container you use can make a huge difference in how quickly your ice cubes freeze. It is not only the size of the ice cube that makes a difference, but also the shape and style of the ice cube tray.
If you are in a rush, use an ice cube tray that has an air space between each individual cube.
This increases the surface area available for cool air to reach and will give you a frozen cube much faster than a tray with dividers between each cube.
Talking of surface area, the standard cube shape is actually the most inefficient when it comes to rapid freezing.
Fun ice trays with shapes such as stars, flowers, and even animals will greatly increase the surface area of each piece of ice, enabling them to freeze much faster.
Many of us use standard plastic and silicone trays to freeze ice, as they are durable and long-lasting. However, swapping to a stainless steel tray will give you frozen ice much faster.
The only problem with stainless steel trays is that it can be difficult to extract the frozen ice cubes when you are ready to use them.
What Is The Best Freezer Temperature For Freezing Ice?
The standard temperature for most home freezers is 0°F. This is the optimal temperature for making ice, as well as keeping your food perfectly frozen.
Temperatures colder than this will cause freezer burn, so don’t be tempted to set your freezer to the lowest possible temperature!
However, every time you open your freezer, the temperature will increase. It then takes time to get back to 0 degrees again, which will prolong the time it takes for your liquid water to turn to ice.
Ideally, avoid opening your freezer for three hours if you want to make ice rapidly.
Another factor that affects freezer temperature is the contents of the freezer. If you put room-temperature food in your freezer, this will temporarily increase the overall temperature of the freezer.
If you can, chill your food in the refrigerator before placing it in the freezer.
Does Ice Freeze Faster In An Empty Or Full Freezer?
Speaking of the contents of the freezer, which is better – an empty or full freezer?
Freezers that are kept fuller will hold their temperature much more consistently. The mass of frozen foodstuffs will help to quickly return the freezer to the optimum temperature as soon as the door is closed.
If your freezer contents are looking a bit sparse, you can “fill” your freezer with other goods to fill up the space and keep it running efficiently.
Use empty cartons to make large ice blocks, which will give your freezer a helping hand when it comes to maintaining the perfect temperature.
However, air does need to circulate within your freezer, so don’t be tempted to cram it too full! Always keep your freezer about three-quarters full, but never full to the brim.
To make ice rapidly, sit your ice cube trays on top of foodstuffs that are already frozen if possible.
Does Hot Water Freeze Faster Than Cold?
Now, this is a crazy but true fact – hot water freezes faster than cold! Named after a Tanzanian high school student, Erasto Mpemba, this phenomenon is called the Mpemba effect.
In the 1960s, Mpemba began to investigate how quickly different temperatures of water froze.
His first observation was that when he made ice cream with hot milk, it froze faster than when made with cold milk. His teachers did not believe him, so he started his own experiments!
Amazed by this discovery, scientists replicated Mpemba’s research. They found that in many cases, warm water was faster to freeze than cold water.
All because a young student refused to believe his teachers when they said he was wrong!
But how does the Mpemba effect work, and what is the optimum temperature for faster freezing?
Unfortunately, this is a massively complex and slightly controversial subject! It is not quite as simple as warm water freezing faster than cold, and other variables can affect the freezing rate of water.
Scientists have not yet agreed on the reasons why Mpemna’s phenomenon occurs, but they all agree that it does happen!
If you are tempted to try making ice as fast as possible, you have two options when it comes to the temperature of your water.
You either need to start with water that is as cold as possible or at boiling point. Lukewarm water will take longer to freeze than both of these.
Ideally, use water from a jug stored in the refrigerator to make ice. If the water from your cold tap is icy cold, this can also be used to make ice rapidly.
If neither of these options is available to you, try the boiling water trick instead! Just take care not to spill hot water over yourself as you fill your ice cube trays.
What Is The Best Way To Freeze Ice Quickly?
So, you’ve forgotten to fill your ice trays ready for a big summer party? Don’t panic – if you follow these steps you can have ready-to-serve ice in just 2 hours!
Select The Right Ice Cube Tray
Silicone and plastic ice trays are not as fast at freezing ice as stainless-steel ones. If you don’t have this option, then try a disposable plastic ice cube bag laid in a metal baking tray.
If silicone or plastic trays are your only options, pick the ones with the smallest ice cube compartments, with an air gap between each one. Funky shapes such as stars and flowers will freeze faster than traditional cubes.
Check Your Freezer Temperature
Your domestic freezer should be set at 0°F. Don’t be tempted to turn it down lower than this – you will not greatly speed up the rate at which your ice sets, and you may ruin all your carefully frozen foods!
Use Either Pre-Chilled Or Boiling Hot Water
Lukewarm water takes longer to freeze than boiling water. If you have chilled water in your refrigerator, this will freeze fastest of all.
Position Your Trays Carefully In The Freezer
Place your trays directly onto a surface that is already frozen. If you are using chilled water, you can place your trays onto frozen foods.
Boiling water should be placed directly onto a freezer shelf, to prevent accidental defrosting of your food.
Don’t Open The Door!
Shut the door and walk away, for at least 2 hours. Opening the door before this will only delay the freezing process.
Check your ice after 2 hours – hopefully, you should have perfect ice cubes! If not, leave it for another 30 minutes then check again.
How To Keep Ice Frozen
So, you’ve gone to great lengths to get your ice frozen ready for your summer barbeque or cocktail party.
But what a disappointment when those lovely icy cubes all quickly melt in the sunshine! Or even worse, they stick together into a huge, unusable lump.
To prevent this from happening, you need to keep your ice cubes at the perfect temperature. There are some great and ways you can do this:
- Use a purpose-made ice bucket
- Use a cool box
- Keep the ice in the refrigerator
- Put ice packs underneath your ice cubes
Then all you need to do is pop a bunch of ice cubes into your glass, pour over your beverage of choice, and enjoy! Cheers!
Now that we’ve gone over how long it takes to freeze ice, let’s take a look at a few related questions on the subject!
How long does it take for homemade popsicles to freeze?
Making popsicles at home can be a fun and healthy way to make ice-cold treats for all the family. Best of all, you can make them in all your favorite flavors, so no more yukky lime popsicles left at the bottom of the freezer!
But how long do homemade popsicles take to freeze? Homemade popsicles will freeze in between 4-8 hours. The time they take depends on the amount and type of juice you use, plus whether you have added any real fruits or sugar.
Can anything other than water be used to make ice cubes?
If you want some fun and quirky ways to cool down your drinks, you can make ice cubes from many other things! Some of these may take longer to freeze than water, so remember to prepare them well in advance.
Other liquids which can be used to make ice cubes include lemonade, cola, coffee, fruit juice, and fruit smoothies.
You can also add solid items to your ice cubes to make fun and tasty additions to your drink. Fruits, mint, cucumber, and even flowers can work really well for this.
Simply pop them into an ice cube tray, pour over the liquid of your choice and leave for several hours in the freezer.
How is crushed ice made?
Crushed ice is a popular ingredient in many drinks recipes, particularly cocktails and iced coffee. But what is the best way to make crushed ice?
Crushed ice is made by taking standard ice cubes and shattering them into smaller pieces.
The best way to do this is by placing your ice cubes inside a plastic bag or folded tea towel. You can speed up the process by running hot water over the ice cube tray first, which will help to crack the ice cubes.
Place the ice in its bag or cloth onto a solid surface, and use a firm object such as a rolling pin to bash the ice. Continue until your ice is the perfect consistency to turn your summer cocktail into a delightful, slushy drink!
How is clear ice made?
Do you ever look at the ice cubes in restaurants and cafes and wonder how they get them so clear and smooth? Ice made in home freezers normally comes out rough and cloudy, so what do they do differently?
Clear ice is made by ensuring the liquid water is completely free from air bubbles as it freezes.
You also need to ensure that your ice freezes from only one direction, so all sides of the tray except the top must be insulated. The best way to do this is to buy a purpose-made ice tray designed for making clear ice cubes.
Making clear ice is all about freezing the ice as slowly as possible, forcing the air bubbles to the bottom of the tray. This is not a good method if you want to make ice quickly!