Coffee is a fickle mistress. Take a sip too soon and you risk searing your tongue, wait too long and it becomes undrinkably tepid. But with this ingenious phase-change mug prototype, your coffee will cool to a perfectly drinkable 140 degrees and stay there for hours.

"Our goal was to create a coffee mug that will take piping hot coffee and cool it to a hot, but drinkable, temperature—and keep it at that temperature for a long time," Logan Maxwell, the co-creator of the aptly named Temperfect mug, told R&D Mag.


The secret of the mug's temperature-control abilities is its unique insulation material. The Temperfect uses a three-wall design—an inner wall that holds the liquid, an outer wall that you hold, and a middle wall separating them. Between the outer and middle walls, there's an insulating vacuum (just like most such mugs), but between the inner (coffee-facing) wall and the middle partition, Maxwell injected a proprietary nontoxic phase-changing chemical. This material is a solid at room temperature but will melt into a liquid when heated by the coffee. This melting sucks out just enough heat to cool the coffee to 140 degrees and transfers small bits of that energy back into the liquid over a long period of time to maintain the 140 degree mark.

"I did some research and found that most coffee is served at between 200 F and 185 F, and that coffee can burn you at any temperature above 140 F," Maxwell continued. "So we set our 'ideal' temperature at 140 F." The Temperfect mug is currently on Kickstarter (and has already broken its $23,500 goal with 20 days to go) Now if there were only something we could do about this damnable hot porridge. [Kickstarter via R&D Mag]