Brainstorming: Crystal Clear Ice Cubes from 15x1" silicone cube trays?
UPDATE at the bottom of this post!
So, you may be familiar with various methods to get crystal clear ice for cocktailing, be it using an insulated tray so that ice freezes top down, or a double wall method, where, again, ice freezes top down.
But even with these methods, part of the block of ice you create still has cloudy parts in it, but they’re all at the bottom. Here’s two methods (also read my comments on the side):
So I favour the latter method because it got me thinking — what if you found a way to evacuate the oxygen-laden water from the cube tray during the freezing process?
I should note, I haven’t tried this yet. I will soon, but for now, I have no idea if it will work, if it will distort the shape of the cube or what. But here’s my idea, based partially on the second video.
Take one of those standard silicone 15 cube trays that do 1" ice cubes. Very carefully cut a small hole (maybe as small as 1–2mm diameter) in the center of each cube section (or corner of each cube section, maybe that will work better).
Find a plastic container that is at least 2x the width, depth, and height of the 15x1" ice cube tray. Fully insulate this container all around its sides and especially its bottom. Place some spacers in the bottom of that container; their purpose is to elevate the 15x1" cube tray by at least 1" or higher. Place your 15x1" ice cube tray on top of the spacers, making sure its’ height does not go past the entire container’s height.
Fill with water so both the main container and the 15x1" are full up to the top of the interior ice cube tray. Place in your freezer, and come back to it in 24 hours. Disengage / chip away the larger ice from the main 15x1" tray (like the second video above).
My theory is, all the oxygenated water will push through the tiny holes you put in the bottom of each cube section, into the larger container, leaving just pure, and crystal clear ice in the main ice cube tray.
Concerns
I don’t know enough about fluid dynamics and phase changes (gas to liquid to solid) to know if this will actually work — will oxygenated water be forced through tiny apertures put in the bottom of each cube section.
Also, how big or how small a hole? If the hole’s too big, will the cube deform in the soft silicone ice cube tray? Will the tray itself deform because of the double water bath thing you got going on? Is a corner hole better than a centre hole?
Last concern is, you basically sacrifice one of these 15x1" trays (about $6-$10 depending on the brand) if it doesn’t work. ;)
Update!
Seth Mills (a coffee nerd I know) actually did this test, and it works! It is important to make sure you elevate the tray so it’s top lip is higher than the surrounding water, but otherwise, it works great! A small hole in the middle of each cube compartment is all it took. Seth is posting the details on Twitter, and I’ll share some links soon!
