Clear ice is a mythical creature. If you’ve ever been to a fancy cocktail bar, you may have noticed the perfectly clear ice they serve in the drinks.
Cocktail bars of this caliber achieve this high quality ice by procuring (or creating their own) large bricks of ice with large machines, which they then chop into chunks suitable to fit in a glass.
Achieving this clear ice at home, however, is a different beast entirely.
In designing what ultimately became the Neat Ice Kit, we tried everything. This post will illuminate some of the common myths and misconceptions about achieving clear ice at home, and outline the one true path to clear ice bliss.
So, why even go through the trouble of making clear ice? If you are the type that enjoys making cocktails at home, the small amount of extra effort makes a huge difference. For one, it looks awesome. Cocktails are thoughtfully constructed, and, in our eyes, it’s fun to be a little bit fussy about them. For some people, it is extremely satisfying to put some care and attention into something. Think: trimming a bonsai tree. Or being fussy with your coffee. It ticks a box for a certain personality type. And you can’t argue with the result; a perfectly clear ice cube is a thing of beauty.
In short, many will think clear ice is not “worth it,” but we find both the process of making it and the end result, rewarding.
In the quest for clear ice at home, we first started by simply boiling the water before freezing. I can’t tell you how many times we’ve seen this myth online. “Just boil the water before you freeze it and it will be perfectly clear!” No. We’ve tried it any number of ways, and the results are disappointing.
Just look at this subpar ice. The leftmost ice was made with room temperature water. The ice in the middle was made with boiled water, placed into the freezer hot. The ice on the right was boiled, allowed to cool, boiled again, and then placed in the freezer after cooling once again. I don’t see much of a difference, do you? And one thing is for sure: they are cloudy as shit.
Another popular myth online is that using distilled water will yield clear ice. It is true that different water types do have some effect
on the resulting ice, but it may not be what you expect.
From left to right: generic distilled water, generic purified water, and Ozarka bottled water. As you can see, the distilled water is by far the worse. In every experiment we’ve run, distilled water is incredibly “streaky.” So I think it’s safe to squash the “distilled water yields clear ice” myth.
The important thing to take away from this experiment is that water type does matter, to a degree.
The Ozarka water is less cloudy than the other two. But the water alone is not what determines if the ice freezes clear or not.
Stated simply, water freezes from the outside in. The part of the water exposed to the cold outside air freezes first, and slowly
moves inward until all the water is frozen.
This process is what yields cloudy ice. Because the exterior freezes first, a shell is essentially created, which traps all the impurities and air found in the water. As the freezing moves inward, they are trapped in the middle, creating an unappealing milky white cloud in the center.
After months of research, we found that the key to creating clear ice at home is to control the direction the ice freezes.
Rather than freezing from the outside in, forcing the ice to freeze top to bottom pushes all of the impurities and air to the bottom. This same principle is why ice from a frozen lake is clear on top.
The way we achieved that is an insulated mold. The water is exposed to the cold air on top, but insulated with foam on the sides and bottom. The result is a brick of ice that is crystal clear in the top half, as the cruft is pushed into the bottom half of the brick.