Hi, Casey from Ice Lab here. To make clear ice we use a clinebell machine. The clinebell is 3 basic parts when it comes down to it. A cold plate on the bottom, the water bin in the middle and a water pump on top. So as you may have already imagined the ice freezes from the bottom to the top while the pump circulates water over the newest (top) freezing layer. “But Casey wouldn’t the water pump eventually freeze?” Yes, the water in the pumps eventually freezes but we try to remember to turn them off before this happens.
This might seem like a lot of work to freeze ice. But, it is very difficult to make clear ice even when starting with ultra pure water. The cloudiness you see in ice cubes is mostly air trapped in the ice. Because ice is typically frozen from the outside towards the center, the bubbles concentrate in the center of the block. One might think the bubbles would be evenly distributed but it is not the case. To explain this we have to get pretty sciency. Ice is just water forming into a low energy crystalline state. Ice crystals want to form in their lowest energy state or a perfect repeating pattern of the same structure over and over again (just H2O). When you throw in air or dirt that disrupts the lowest energy state. So those non water items are not trapped in the ice until they reach a higher concentration toward the center making it more and more likely the non ice will stick in place.
So now we know ice not only has whatever solid particles the water has in it but also gas. So even if you start with perfectly clean water you still get air bubbles. The clinebell solves this by agitating the top of the ice as it freezes pushing the debris and gas bubbles to the top. Unfortunately, you then have to cut the very top off of the block where all of the debris and gas collects. Once you cut the top off you have a clear block. If you want to start with a 300 Lbs clear block and carve you can always drop by and purchase one for $99.00. If you need some delivered for a class or party fill out our contact form with the details and we will get back to you with a quote