Methods For Making Clear Ice

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We've developed a little bit of an unhealthy obsession with creating clear ice.  Here is what works for us.

Boyle Law's Insulated Cup Method (our favorite for honest ice molds)

Use  P_{1}V_{1}=P_{2}V_{2}\, to create crystal clear ice and avoid bulging

You will need a 14 or 15 oz insulated cup and a single iced mold. You should do this over a sink.

1.  Fill insulated cup with water.

2. Slowly dip the mold into cup and completely submerge.  Make sure that no air bubbles exist in the mold.  If bubbles exist you need to start over or else you will have air bubbles that float to the top and cause holes.

3.  With the mold completely submerged, turn it upside down so that letter is facing up toward you

4. With pressure applied to the to the "new" top of the mold, pour out most of teh water out of the insulated cup.  Leave a shallow layer of water at the bottom.  Not too much or the mold will be difficult to remove but enough to make sure that the bottom of the mold is completely submerged still.  You are using Boyle's Law.

5.  Place insulated cup in the freezer.  Depending on your freezer, remove in 12 to 24 hours. 

The Cooler Method 

This method seems to be the most common and easiest to do. 

You'll need a small cooler that will fit in your freezer.  Alternatively, you can make a foam (insulated) box.

Option 1. Fill molds and place in bottom of the cooler. Place cooler in freezer with the lid off.

  • If you experience bulging, use option 2 or 3.

Option 2. Same as option 1, but add a shallow layer of water in the bottom of the cooler.  You may have better results if you slightly raise the mold off the bottom of the cooler, like setting the mold on a small cooling rack. Place cooler in freezer

Option 3

  1. Fill Cooler with enough water to completely submerge the molds.
  2. Submerge the molds taking care not to create air bubbles inside of the molds
  3. Turn the molds upside down
  4. Dump out or suck out water until the only the bottom rim of the molds are submerge.  
  5. Place molds in freezer


1. Take out of freezer before water freezers all the way to base.  This will leave liquid water in the center and lower regions of the cooler.  The benefit of this is the impurities have not been trapped in the ice and you will be left with only clear ice.

2.  Let the ice freeze completely.  The impurities are frozen in the bottom center of your rectangle big cube.  You are going to have to cut that out.  Its more work but you should still have a top layer of crystal clear ice.



1. Irregular ice crystals are the enemy.  The best defense against irregular crystals is controlled or directional freezing.

2. We do not boil water, use distilled or purified water, otherwise special water.

Method 1 

The Cooler Method


Method 2

Insulation, water reservoir, and mold with a hole

The products to create clear ice you find online usually use this method.  They will charge you a lot for some Styrofoam in the shape of desk organizer. This method takes the cooler method a step further and eliminates the need to take cooler out after a predetermined amount of time.  As the ice freezes from the top down, impurities are pushed down through the mold and hopefully outside the hole at the bottom.  


Ice is still connected and sometimes difficult to remove.  

Ice still isn't clear. 

Big and bulky.  3/4 of the contraption is water that is unusable, must be emptied out every time.

 Method 3

Icicle method 

Just like icicles on the side of your house, water is run over a freezing device and layers of ice build up until clear ice is formed. 

Method 4

Suction Method

Freeze from all directions, and then impurities are sucked out of the ice cube.

 Method 5

The Shackleton Method

Coming Soon...