How to Make Clear Ice
Our complete guide on how to make clear ice spheres, cubes, and other shapes.
First, in order to create clear ice, it’s important to understand how ice is formed. When water is subjected to temperatures at or below 32℉ (0℃) the molecules begin to slow down and formations of crystals occur. This process is called crystallization and it typically starts with an impurity in the water, such as minerals or even trapped gases like oxygen.
Also, in most environments, water freezes from the outside in, which concentrates impurities and air bubbles (from the trapped gases) toward the center of the ice. This is why your traditional ice cubes in the freezer tray are so cloudy. The water is rapidly frozen from the outside, causing the impurities to be pushed into the center of the ice.
- So does this mean you need “pure” water to get clear ice? Nope. Water is never really pure and always has some amount of minerals or gases.
- Ok, if I can’t purify my water, then how can I get a clear result? There’s one more aspect of water that is key to getting clear ice and it’s all related to the speed in which water is frozen.
When crystallization happens quickly, many small crystals are formed and those reflect light resulting in a cloudy appearance. However, when crystallization is slowed, the crystals are both fewer and larger, which results in more clarity.
The trick to achieving consistently repeatable results for clear ice is essentially two fold: #1) slow down the freezing process and #2) direct those impurities outward. In order to achieve this with traditional home freezers, a clear ice system with directional freezing is needed. A regular ice tray allows water to be hit on all sides from the cold environment, which concentrates the impurities towards the center of the cube. However, if freezing is limited to one direction it slows down the freezing process and drives impurities outward. In order to achieve this for ice cubes or spheres, insulation is needed to guide the freezing process. There are many DIY solutions to do this, but they typically require the use of small coolers that take up lots of available freezer space.
What is the best water to use?
Achieving clear ice does not require boiled, purified or any specially prepared water. The trick to getting a crystal clear result comes down to directional freezing using a quality clear ice system. From a taste perspective, however, this is completely subjective. If you like the taste of your home tap water, then that’s completely acceptable to use for your clear ice. If you prefer filtered or purified water to drink, then by all means stay consistent with your ice.
Does clear ice taste better?
Not necessarily, but it definitely enhances a cocktail or any craft beverage. Let me explain… Have you ever heard the expression that we “eat with our eyes”? The same can be said for drinking, especially when it comes to a craft cocktail. Think about a seared steak versus a pale piece of meat… If you’re visualizing the first one and starting to salivate, you’re not alone. Now, translate that to your favorite cocktail. Maybe it’s an Old Fashioned, a lowball mixed drink or maybe you’re more the straight scotch or bourbon. Doesn't crystal clear ice nested right in the center of it sound more appealing than a cracked cloudy cube?
Standard Sphere Ice (left) vs. Clear Ice Sphere (right)
Does a clear ice system take up a lot of space in my freezer?
There are plenty of resources for creating your own DIY solution using a small cooler, but those will certainly take up a significant amount of freezer space. Some specialty clear ice systems offer a minimal footprint at a similar cost of the individual DIY materials. If you’re looking to build something and have a bunch of unused freezer space, then go for it! However, if you’re interested in a compact solution there are many great options that can produce 1 clear ice sphere or 2 clear ice spheres at a time.
How do I use a clear ice system?
Using a good quality clear ice system is surprisingly easy. Typical manufactured systems are comprised of an insulated sheath, a base reservoir and a rubber ice mold. If it’s the first use, make sure to clean with soapy water, then insert the base reservoir into the insulated sheath. Fill the reservoir with your water preference and then place the unit into your sink. Next, place the rubber mold pieces together and slowly drop them into the reservoir. Some water will overflow into the sink and there may be some at the top of the rubber mold. Simply tilt the unit to pour off the overflow and then place directly into the freezer. You should have perfectly crystal clear spheres in about 4 hours.
If you’re “reloading” the unit after removing from the freezer, make sure to run hot water into the reservoir to remove the cloudy ice at the bottom. This is critical, as the bottom is where the impurities are pushed during the directional freezing process. Once it’s ready, simply repeat the steps above and place back into the freezer for the next batch.
How do I store ice spheres for future use?
There are many solutions, but a simple plastic or a silicone reusable freezer storage bag work well without taking up much freezer space. Stackable ice sphere trays are also a great option to maintain organization, and some are even suitable for serving.
What are the benefits of clear ice spheres?
First off, clear ice just looks cool and more appealing with a craft cocktail or beverage. The other really important attribute is that ice spheres melt slower than traditional cubes. Spheres have less surface area, which translates to a slower melting process. If you’ve taken the time to craft a home cocktail, chances are you want to savor it without it getting watered down. Ice spheres will not only minimize watering down your drink, they’ll also keep it exceptionally cold when using the right lowball glass.
Additional Clear Ice resources:
- Read The Perfect Whiskey Ice Cubes are Round to learn more about the benefits of sphere ice cubes.
- Click here to see our full assortment of Clear Ice Systems.
- Tags: Definitive Guides
- Brian C.