Most of us use cubes made with tap water, using either an ice cube tray or a built-in ice maker. They tend to be cloudy and sometimes don’t last as long as we’d like. But, ice is ice, right? Not necessarily. Home-made ice freezes from the outside in. Air that is dissolved in the water, plus any minerals (worse if you have hard water) are pushed to the center, last to freeze, where the create bubbles and haze. The resulting ice cubes contain less actual ice than bubble-free ones of equal size would, and when they melt you may find a sediment of the previously-dissolved minerals at the bottom of your glass.
To avoid this, use distilled water (no dissolved minerals) and bring to a boil briefly, then cool and freeze (the boiling drives out most of the dissolved air). You’ll get clear, sediment-free cubes that last a good deal longer. Worth the effort? Maybe only for special occasions!
I’ve found that using a water filter produces fresher ice than tap water and may be enough to save the work of boiling water. Thoughts?
I am sure a filter helps with minerals, but I don’t think it takes out the dissolved air, which boiling does. I’d give both a try and compare the results.
Have you tried the boiling technique? I have been questing for perfectly clear ice for some time and even boiled water doesn’t seem to work for me. I think it might be a problem with density – the ice contracts and then expands after freezing? Have you actually managed to make clear ice cubes, and if so, can you give the exact parameters?
Have you tried boiling distilled water? I can’t say I’ve gotten “perfectly” clear cubes, but that’s the closest I have gotten.
I will try the boiled distilled method and see what happens. I’ve also been doing directional freezing by insulating my ice tray – check out http://alcademics.com/ice/ for some really interesting research.