Journalist and founder of the cocktail blog Alcademics.com Camper English knows a thing or two about ice. In a quest to produce a perfectly clear block, he spent nearly a year experimenting with the stuff, testing and re-testing, filtering and refiltering, freezing and refreezing.
I asked him: What am I doing wrong? How can I make a perfectly clear sphere of ice?
Well, to make a long story short, it turns out there is a way, but it doesn't involve using either of the molds I tested. Camper explained that the problem with the molds is that the ice will begin to form on the outside first, driving air bubbles and impurities to the center of the sphere, where they'll inevitably stay trapped.
Camper did, however, discover a way to make a perfectly clear block of ice in his home freezer. You can read all about his ingenious method on his blog, Alcademics.com here. Hint: "It's all about controlling the direction of the freezing."
Okay, so far so good. But, in the absence of advanced ice-carving skills, how can you possibly go from a block to a sphere? Well, there is one way...
Once one of his blocks was ready, Camper brought it over to a bar across the street from him and tried out one of these astounding - albeit pricey - machines that reshape ice using pressure and heat. The final result? A beautifully clear, seamlessly shaped sphere. Okay, maybe not the most accessible option for most of us, but nice to know it can be done.