ice cube

[jimmyninja]

how do you make a clear ice cube

[jason1980]

im sure I heard somewhere that you can only make a clear ice cube with water full of a lot of added calcium. Also really excessive high levels of added calcium also keeps the water in liquid form at freezing point so that it never freezes at all.

[gary baldy]

Use boiled water.

[boobesque]

the 2 answers above may well work however i have never heard of them. i have heard that the speed at which water freezes determines the clarity. slow freezing gives the ice time to crack while the rest is still freezing giving it the whitish look. freezing it very fast produces lovely clear ice. i believe that pressure can also make a difference

[gen2]

The cloudiness of an ice cube may be due to two things: Deposited solids that were previously dissolved in the water, and bubbles of gas that were also previously dissolved in the water.

Boiling water will remove any dissolved gas and so will cure that cause

Boiling will also remove dissolved calcium salts that cause temporary hardness and so mostly cure that cause.

The only possible remaining cause of the cubes not being clear is from other dissolved minerals. In mractice, there will be minimal quantities of these for most of the UK's drinking water supplies, so pre-boiling the water should be the most effective way of creating clear ice cubes. Try it and see.

[JudgeJ]

You will notice that, usually, ice provided in pubs and restaurants is clear. This has nothing to do with the water used. Ice in these establishments is made by a machine that produces one cube in less than one second. That is, the water is frozen extremely quickly. This ties up with boobesque's explanation.

[mr_pointment]

http://www.hunkinsexperiments.com/pages/waterparttwo.htm