Posted on 19 Oct 2014 01:39
Why are bartenders using spherical balls of ice in drinks, nowadays? Is it just to impress you? What is the purpose of putting one big ball of ice in a drink and how is this different than using some ice cubes? Should you ask for spherical ice, if it is available? Is there a practical way to make these at home?
Why Are Round Ice Cubes Used?
Before you yell at me, I know that there is no such thing as a round ice cube. But since we are so used to calling pieces of ice 'cubes' regardless of their actual shape, most people will call ice balls round ice cubes and my usage is to help more people find this article and get their questions answered.
So, why do bartenders use them?
Spherical ice is not used just to impress you. Bartenders use different types of ice for specific purposes, for the most part. To understand why round ice is used, we can consider something like a whiskey with an ice cube. As you may know, some people like a splash of water in their bourbon, rye, Scotch, Irish whiskey, etc. (it's bigger with Scotch). They say that this brings out the taste. Some people like one or two ice cubes to chill the liquor, and, to dilute it somewhat. Here is the problem. An ice cube chills and dilutes the whiskey, and then keeps on diluting it as it melts. Of course, this is going to happen with any ice, but what if you could slow down the melting of the ice, while still using actual ice (instead of "fake" ice)?
Round ice helps solve this problem. You see, it's about volume and surface area. A sphere exposes less surface area for the same amount of volume than a cube of ice. So, if you have a cube that is the same volume as a sphere, the sphere will actually have a lot less surface area, over 24 percent less. The less surface area that is exposed to the warm liquid, the slower the ice will melt. Therefore, a sphere of ice will melt more slowly in a drink than a cube of ice. This way, you can chill the drink without quickly diluting it. It's science!
You may notice that fairly large ice balls are used, that fill the glass, or almost fill it. This is in order to chill the drink quickly while exposing it to as little surface area as possible.
How Are Ice Balls Made?
But, to make anything round is very, very hard. There is no way you are going to want to take a huge square of ice and sculpt it into a sphere, so I doubt you would try this at home to impress your guests. There are lots of silicone ice molds available to make spherical ice, but the results can vary and sometimes the ice cracks, which kind of defeats the purpose. It is still easier than most other ways, and they seem to work fairly well, for the most part.
Yet, some bartenders really do hack away at a cube of ice to get it into sort of a rough roundish shape, and then run it over water to smooth out the edges until they get sort of a sphere. They then place it in a freezer until they need it.
The other method uses what is called an ice ball press, which I've also seen referred to as a Japanese ice mold. This consist of two heavy metal cylinders, copper or aluminum, which can be connected with pins that run vertically down through the sides. In the end of each of the cylinders is a hemispherical depression. The ice ball press comes in kits that include a tray for making cubes of ice (most of use have ice cube trays that don't actually make cubes). You make cubes of ice, and you place one of the cubes into the depression in one of the cylinders. You connect the other cylinder up top, so that its depression is downwards, then you press it down over the ice cube. What happens next is like magic. The heat transfer from the metal to the ice almost instantly melts the ice cube. As the ice cube melts the cylinders move together until they make contact. What is left is a perfectly round ball of ice. You can watch this parlor trick in the video below.
That sure is is something to watch, but you will not believe the price tag. One of these kits will cost you anywhere from $300 to over $1000! Can you say NOT GONNA HAPPEN?
Your best bet, should you want to make these at home, is one of the round silicone ice molds. Now, you may notice another problem with spherical ice. What good is a fancy ice ball if it is all cloudy? You know that when you freeze ice at home it tends to be cloudy — sometimes completely cloudy. So what if you wanted a perfectly clear ball of ice? Or, perfectly clear ice of any kind? Science helps again.
How Can You Make Clear, Unclouded Ice Balls?
There is not point in worrying about making absolutely crystal clear ice full of all impurities. We just need to address what causes most of the cloudiness. And, that is air. All water contains dissolved air. It's how fish breathe, after all. When water begins to freeze, it does so from the outside in. Ice forms on the outer surfaces of the water first. At the same time, as the temperature changes, air precipitates out of the water to form tiny bubbles. Since the outer parts of the ice cube are frozen, the ice cannot escape, so it just gets "frozen" in place, forming cloudy ice. The cloudiness is basically millions of tiny air bubbles. So, to make clear ice, you have to somehow get rid of the air.
There is no easier way to get the air out of water than to boil it. Boiling forces the air out of the water and then, if you pour the boiling water immediately into ice cube trays, or a mold of any kind and place it in the freezer, you will end up with clear ice cubes — or at least as clear as is practical.
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