Ever feel like the only times you need ice, the tray is always completely empty? You can either fill up a new tray and wait a few hours, or down some lukewarm liquid (delish!).
Next time start with warm water—it actually freezes faster than cold. This counterintuitive hack works because of the Mpemba effect, which makes sense only if you remember an alarming amount of high school chemistry. The Mpemba effect was first discovered by ice cream makers, who realized milk froze faster when it was warm.