Making the Perfect Ice Cube.
Most of us don’t spend much time contemplating the clarity of an ice cube, but for craft cocktail bartenders around the world it is an obsession. Achieving truly clear cubes has become the bartender’s crucible. They are willing to go to fanatical lengths to achieve them. Why does the clarity of ice even matter? It would seem to go somewhat beyond simply the aesthetic.
Cloudy ice signals impurities, they come in the form of irregular crystals and absorbed gases. These impurities (such as chlorine or fluoride) transmit unwanted flavors into the ice, while absorbed gases (like oxygen and nitrogen) form irregular crystals that weaken the cubes.
A compromised cube is more prone to shattering while being shaken. These tiny shards of ice will over-dilute a cocktail and so they must be eradicated. The majority of us have neither the time or patience to do what bartenders consider necessary, we developed a more relaxed technique that will get us as near to clear as is possible.
Make Mine Distilled
First we had to tackle the issue of impurities, those were coming from the water so we needed something a little different than tap water, or even filtered water from your fridge. Purified water removes a lot of contaminants but the issue of fluoride remains. Though distilled water is purified not all purified water is distilled. The process of distillation is comprised of boiling water which transforms into steam, the steam is gathered and upon cooling returns to water again, but this time without any of the chemicals or impurities.
(To almost completely remove any impurities from the water and minimize the cloudiness reach for distilled water.)
The Plague of Bubbles
Using distilled water however is not enough. Air dissolves more readily in cold water so your ice cubes will be riddled with bubbles once frozen. To do away with the trapped air you first need to boil your distilled water. Then while it’s still extremely hot immediately and carefully pour it into your chosen ice cube tray. The tray you use doesn’t matter too much, just be sure it’s very well cleaned and dried before using it. If opting for a silicone tray we recommend baking it at 350 F for about an hour. This helps to remove any odors it may have absorbed.
(Boil your distilled water before immediately pouring it into your prepared trays.)
The Answer is Insulation
With the impurities almost completely gone, and the bubbles along with them, you may still find a small hazy cloud in the center of your ice cubes. To avoid this you need to insulate your ice cube trays before filling them with water. You can do this simply enough by lining a baking tray with kitchen towels, this ensures that your cubes freeze from one direction, the top. Whereas an un-insulated tray would cool from the outside in every direction, gathering all the impurities in the center, this method pushes them down to the bottom leaving us with practically clear cubes.
Insulate your trays with kitchen towels to ensure your cubes are freezing from the top down. Now that you have wonderfully clear ice cubes, it’s time to get started making and enjoying those now undiluted cocktails!