Clear ice cubes definitely make drinks look prettier and ready for their close-up but there's an added benefit to making clear ice. They don’t melt quite as fast as regular ice, because clear ice cubes have fewer air bubbles trapped inside. While you might be used to seeing clear ice cubes in drinks at restaurants and bars, most ice cubes you’ve frozen yourself probably look a little cloudy or opaque. But this doesn’t mean your water isn’t clean, or that your ice cubes aren’t as pure as your favorite restaurant. Though impurities can make your ice cubes look white or cloudy instead of clear, how you freeze your ice also has a lot to do with whether the cubes look clear. Follow these tips from former bartender Millie Pham to help make clear ice at home.

What Type of Water to Use to Make Clear Ice

Though cloudy ice isn’t always caused by the water you’re using, it helps to start off with the purest possible water. “Cloudiness in ice results from impurities, such as air, minerals, and other things that aren’t pure H2O,” Pham says. “As the water starts freezing, impurities are trapped inside the growing crystal structure, creating a cloudy appearance.”

It sounds a little counterintuitive, but you can eliminate some of these impurities by using hot water. “One of my tips for making clearer ice is to use warm or hot water, since there are fewer impurities in warm water than cold water,” Pham says. It won’t freeze quite as quickly, but boiled distilled water will have the fewest impurities and give you the clearest cubes. But while the type of water you use can make your ice a little less cloudy, to make completely clear cubes, you also need to use a special freezing method.

How to Make Ice Cubes Clear

For truly see-through ice cubes, you’ll want to use a clear ice mold. “This method requires effort and time, but it is a great way to make clear ice if you want to save money and have fun doing so,” Pham says. A clear ice mold can range from $25 up to about $50, but you don’t necessarily need anything too fancy to make clear ice. If you want to learn how to make clear ice balls, you can also find directional freezing molds with a spherical shape.

Clear ice molds work by using directional freezing. Unlike regular ice cube molds, which allow water to freeze from all directions, special clear ice molds are usually insulated on the bottom and sides and open on the top. This forces the water to freeze in just one direction (called directional freezing), which forces any air bubbles or remaining impurities out of the ice in that direction, leaving you with clear ice cubes. Regular ice trays allow ice to freeze from all sides, trapping air and minerals in the center of the cubes.

Another option is to buy a clear ice maker, but that’s a much pricier route. “A clear ice maker is the most effective, least hassle, and fastest way to make clear ice if you don’t want to put any effort into making the clear ice,” Pham says. But while some machines can start producing clear ice cubes in less than an hour, most will cost over $200, and produce much smaller cubes than clear ice mold.

How to Make Clear Ice at Home

While you’ll have to monitor a clear ice mold in the freezer, it’s one of the most budget-friendly ways for most people to make ice cubes clear at home. You also don’t have to worry as much about using pure water. Though you can use hot distilled water, even traditional tap water will freeze clear in a directional freezing mold. Here’s how to do it:

Step 1: Fill the Mold with Water

Just like a traditional ice cube mold, fill the clear ice mold with either distilled or tap water.

Step 2: Place Tray in the Freezer

Set the clear ice mold in the freezer. If the opening is at the top, the ice will freeze from top to bottom. It may take about 15 to 20 hours for the ice to freeze.

Step 3: Remove Tray from the Freezer

Once the cubes are frozen, remove the ice mold from the freezer, and take the ice cubes out of the tray. They should be completely clear and ready to use.