How to Make Clear Ice Cubes
Nothing can ruin your drinking experience more than having ice cubes that look hazy or cloudy. Cloudy ice always indicates the presence of trapped air and minerals. While these do not bring harm to your health, they do make your drink less appealing. Here is how you can make crystal clear ice cubes.
There is only one type of water that you should use if you want to make crystal clear ice cubes. This is purified or distilled water. It is important to understand what makes ice cubes turn cloudy. Ordinary water contains minerals as well as air bubbles. When you pour water into your ice cube mold, the first part that freezes is the edges. Minerals and contaminants move to the center of the ice cube. This gives you the classic cloudy-in-the-center type of ice cube.
Distilled water already has its minerals removed. The same is true with purified water. Water goes through a process called reverse osmosis, removing minerals from the water. When you make ice cubes using either distilled or purified water, you reduce the tendency of the ice cubes to turn cloudy.
However, there is still the issue of air bubbles. These may not lead to a hazy ice cube. However, they can make it look like a frozen sponge.
One way you can address ice cube haziness is by boiling the water twice. Boiling helps in the elimination of air bubbles. If you boil water once, you may not be able to remove all of the air bubbles. That is why you have to boil the water again.
You can also employ the same method using ordinary tap water. Boiling twice should help remove the pockets of air in the ice cubes. However, do not expect that it will be crystal clear. There will still be some level of cloudiness in the ice cube. Remember, tap water is not distilled or purified. As such, it contains minerals that can accumulate in the ice cube.
Sometimes, boiling water twice does not always give you crystal clear ice. There will still be some cloudiness in the ice cube’s center. As mentioned, water freezes from the outside. This is where directional freezing can help. In this method, the length of time of freezing water will be very long. What you want to achieve is for the cloudiness to move towards a part of the ice cube where it is easier to remove – the edges.
To do this, you will have to employ a slow freezing technique. Pour your boiled distilled or tap water in your ice cube molds. Set your freezer to the highest possible temperature setting. Place the ice cube tray and let the water freeze for at least 24 hours. This is enough time to push the air bubbles and impurities towards the top of the ice cube. You can then shave them off before serving.
Making crystal clear ice cube requires some basic understanding of science. Your best bet, however, is to use purified or distilled water. Boiling it twice helps guarantee a less cloudy cube. Slow-freezing it makes it crystal clear.