In preparation for some cocktails this weekend, I decided to to try and make some clear ice. Having heard that the double boiling and distilled water methods don’t work reliably, I decided to use some science. Slow freezing, like icicles or frozen lakes, gives time for the water bubbles to escape the ice as it freezes. This has been called the ‘lake effect’. Here are my results: 
Not perfect, but pretty darn good if I do say so myself. I also didn’t let the chunk freeze all the way as I was impatient.
Directions:
Put your water of choice and mould of choice (you can also just make a large block) into a cooler that will fit in your freezer. Fill, making sure to fill all the nooks and crannies, to at least about a half inch above your mould. Let it freeze for 2-3 days in your freezer, then use a serrated knife and hammer to chisel out your moulds or make free form smaller chunks. Letting it sit out for about an hour before hacking away lets it temper and seems to prevent shattering. Enjoy!