A couple of engineer buddies have designed the latest must-have accessory for the coffee drinker. Joulies are metallic beans you drop into your hot cup of cofee to make it exactly 140 degrees. They haven’t even been manufactured yet, but already the project has accumulated some $305,000 in Kickstarter cash. I guess a lot of people are tired of blistered tongues.
Each Joulie is a small metal shell filled with a phase-change material that melts at 140º Fahrenheit. (Some people might prefer 155º — perhaps there will be a version for us.) So the Joulies absorb heat from the coffee till they reach 140º, and then start emitting heat. The effect (if you put in enough Joulies for your volume of beverage) is to maintain the coffee at the desired temperature for long enough to savor it. Using an insulated cup is recommended also.
Shell Material: Polished Food-Grade 18/10 Stainless SteelInner
Material: Proprietary Phase Change Material (PCM), melting point 140°F
Displacement: 0.75 oz (1.5 Tbsp) per bean
Coffee Volume Per Bean: 5 oz including bean (4.25 oz without bean)
Coffee Volume Reduction: 15%The “Right”
Temperature Range: 140°F to 130°F
From the inventor: “This amazing feat of thermodynamics happens thanks to a special non-toxic material sealed within the polished stainless steel shell. This material is designed to melt at 140 degrees Fahrenheit, and absorbs a lot of energy as it melts. This is how Joulies cool your coffee down three times faster than normal. Once it reaches this temperature, the special material begins to solidify again, releasing the energy it stored when it melted. This is how Joulies keep your coffee warm twice as long.”