Coffee Joulies: Kickstarter project keeps your coffee at the right temperature

Direct link to video: http://www.youtube.com/watch?v=JRpfYAaMRIE

Now certain herbal teas on the other hand are brewed at lower temperatures to keep from scalding the leaves. That may be what you're thinking?

I'm curious, what's your optimal temperature and how do you brew your joe?

My guess? The phase change material could be as simple as beeswax. (Melting point of 62-64 C, very close to the melting point they specify.) They'd want to optimize for heat capacity, but there are plenty of natural and safe materials in the ballpark.

"Yes! Joulies are perfectly safe when used properly, and in fact make drinking coffee safer than usual by reducing the risk of burning your mouth." (Emphasis mine)

The whole "it's actually safer because burning your mouth is unsafe" isn't very comforting, and the "safe when used properly" clause makes me think "what happens if I dont' use it properly?" The fact that the inner material is proprietary and is somewhat of a mystery doesn't help either.

Still a very interesting idea, but I think the early-adopters and overall target market for theses things overlaps largely with more conscientiousness food shoppers who want to know exactly what's in the food and drink they buy.

Also, the photo of the metallic bean pile could use a coffee cup next to it to show scale. I saw that and thought, what if I swallowed one or choked or on it? It wasn't until I scrolled down that I saw the size of the bean.

for example, water takes about 75J to heat one mol by 1K. but it takes about 285000J to change one mol of ice to one mol of water

So, they have this lump of metal, that has a core of some other material that presumably changes state at the preferred temperature of coffee. What this means is that when the coffee is hotter than the joulies, the core melts absorbing a lot of energy. Then when the coffee is cooler than the preferred temperature, the core of the joulies re-solidifies, releasing a lot of energy, keeping the coffee warm.

Weekend projects come and go with hardly a whimper. The hard part comes when you want to turn that weekend project into something people will actually use (or in this case, pay for). Creating a compelling brand, crafting a marketing message that resonates, designing the product so that it "feels" good to use, engineering something durable and long lasting, scaling to meet demand et al? These things require a heck of a lot more than a class in thermodynamics.

Regardless, the market has spoken and 300+ people saw enough value in this thermal mass to support it.