While I'm not going to get in the habit of testing out every clear ice cube maker on the market, I decided to try out the Clearly Frozen tray because they sent me one.
This ice cube tray uses directional freezing, the process to make clear ice first described here on Alcademics back in 2009. This particular system is pretty much the same as in this blog post about poking holes in silicone ice cube trays and using directional freezing to ensure the part inside the tray is clear. The difference is that in the Clearly Frozen device, the shape of the 'cooler' is custom made to fit the ice cube tray and retaining tray.
The device is just three parts: a 10-cube silicone ice cube tray (makes 10 2-inch cubes at a time), a plastic retaining tray to hold the cloudy ice beneath the tray, and the foam insulated box that enforces directional freezing. You put it together, fill it with water, and leave it to freeze. My timing was perfect at a little over 12 hours of freezing - there was still plenty of unfrozen water in the plastic tray so it was easy to separate.
- Makes more cubes than most clear ice cube trays on the market - ten 2" cubes
- More space-efficient relatively than others - it takes up a bunch of space, but you get more ice out of it than with other clear ice makers
- Costs less than others- $25 including shipping
- I have no complaints for my first attempt, but I do have some doubts about its long-term durability. The interior clear tray is quite thin and I could see it cracking. 2019 update: They have updated the interior tray with a much thicker and more durable plastic, so it seems this tray will last a long time.
Personally I will probably continue to to make my ice one big Igloo cooler at a time, because I enjoy the process of breaking up an ice block and don't care that much about having super-square ice cubes. But of the commercial products I've tried, this one has a low price and some nice features.