Buzz
Have you ever wondered why ice cubes served in high-end restaurants are often crystal clear, while the ones you make at home are usually cloudy and white? Regular ice cubes become opaque because air bubbles get trapped and compressed into tiny bubbles, or the freezing process doesn't allow for the formation of larger crystal structures. As a result, cloudy ice cubes are weaker and melt faster than clear, pure ice. Ice enthusiasts have discovered several techniques to make high-quality ice cubes at home, no restaurant required. Try these methods to achieve crystal clear ice in your kitchen.
Steps
The Boiling Water Method
Use pure water. This method helps expel air bubbles and remove impurities from the water before freezing. It's best to use distilled water. Bottled water or any water that has gone through reverse osmosis filtration will also work effectively.
Boil the water twice. The boiling process will cause air bubbles to escape, allowing water molecules to tightly bond with one another while freezing.
- After the first boil, allow the water to cool before boiling it again.
- Cover the water as it cools to prevent dust and debris from falling in.
Pour the water into an ice tray or mold, and cover it tightly with plastic wrap to prevent small particles from contaminating the ice surface. Make sure the water is cooled before pouring it into the tray to avoid melting the plastic. If you want to impress, consider making large ice cubes or spherical ice balls. Nothing is more impressive than enjoying a cocktail with a large ice cube.
Place the ice tray in the freezer. Let it sit for a few hours until the ice is completely frozen.
Then, remove the ice tray and carefully release each ice cube.
Freezing method from top to bottom
Prepare a small cooler box. Use a rectangular cooler box, similar to the ones used for keeping food and drinks cold on a picnic, but make sure it's small enough to fit into your freezer. The cooler box will separate the ice from the freezer's air, forcing the ice to freeze very slowly from top to bottom.
Place the ice trays, molds, or other containers at the bottom of the cooler box. Do not close the lid of the cooler. If possible, use large ice cube trays or several smaller plastic or silicone molds with a rectangular shape.
Pour water into the trays or molds. People who use this method report that tap water works just as well as distilled or boiled water.
Fill the bottom of the cooler box with water, nearly to the height of the ice trays or molds. This layer of water acts as a barrier, ensuring that the cold air does not freeze the top or bottom surfaces of the ice trays.
Place the cooler box, without closing the lid, in the freezer. Ensure that your freezer is not too cold – a temperature between -3 to 8°C is ideal. Leave the cooler box in the freezer for about 24 hours.
Take the cooler box out and carefully remove the frozen ice trays or molds. The ice will have a thin cloudy layer on the surface, but the rest will be completely clear.
Detach the ice that has formed around the tray or mold and remove the ice cubes.
Leave the ice outside for about 1 minute to let the cloudy layer melt away. Now you will have large, clear ice cubes.
High-temperature freezing method
Adjust your freezer to a temperature of around -1°C. This is likely the highest temperature setting available in your freezer. If you don’t want to raise the entire freezer’s temperature, adjust it to your desired level and place the ice tray in the top compartment.
Pour the water into an ice tray or mold and place it in the freezer. Let the water freeze for about 24 hours. The slow freezing process will push air bubbles and impurities out, resulting in clear ice cubes.
Bottom-up freezing method
Unlike the previous method, this one allows you to quickly get clear ice cubes with no cracks, unless it’s your first attempt. This method also works well when using tap water in the ice tray. The air bubbles will escape as the freezing happens from the bottom up. This can be achieved by allowing the bottom of the tray to come into contact with something extremely cold. Ideally, you should let the tray touch a liquid substance, as it will cover the entire bottom and help conduct the heat away faster. A convenient liquid for cooling the ice tray is saltwater.
Fill a bowl with water, then add plenty of salt to prevent the water from freezing, and place the bowl in the freezer. Be sure not to add too little water to the bowl, or the freezing process will cause the water to reach 0°C before the ice forms. The colder the freezer, the higher the concentration of salt needed to prevent the saltwater from freezing. You’ll figure out how much salt is necessary based on the freezer temperature after a few tries.
Leave the saltwater in the freezer for at least 3 hours to ensure it gets really cold.
Boil a small amount of water and then allow it to cool to remove any tiny air bubbles.
Remove the saltwater bowl from the freezer to prevent the water in the ice tray from freezing from the top down.
Pour water into the ice tray, then place the tray into the saltwater bowl in the freezer. At this point, the saltwater will be denser than regular water. The result will be ice without air bubbles, which becomes solid and crack-free because it freezes without any air layers being trapped or formed during the process.
Place the ice tray in the freezer to avoid it from melting.
Put the saltwater bowl back in the freezer so you can skip the first step next time you want to make clear ice cubes.
Tips
- You can find ice trays with dividers if you can't find a cooler box that fits your freezer perfectly.
- Use a stainless steel pot to boil water instead of an aluminum one.
Warning
- Be careful when using boiling water. It’s best to let the water cool before pouring it into a plastic ice tray.
