Your freezer isn’t a sterile science chamber; it’s a crowded, chaotic kingdom of frozen peas and leftover pizza. If you open the door frequently—say, to check on that water every twenty minutes—you’re adding warm air and slowing the process. Tip: Resist the urge to peek. Let the cold do its job.
Water purity also plays a role. Distilled water freezes faster than tap water because it lacks impurities (like minerals and dissolved gases) that act as nucleation points. However, ultra-pure water can supercool—staying liquid below 32°F until a sudden jolt turns it into ice in seconds. Cool party trick? Absolutely. Reliable for daily use? Not so much.
Altitude changes things too. At 5,000 feet, water boils at a lower temperature, but it actually freezes at the same 32°F—it just takes longer because lower air pressure reduces heat transfer. If you live in Denver, expect your ice cubes to be a little lazy.
