Coffee Joulies are small, stainless-steel capsules of phase change material designed to be placed in a covered, insulated container cup of coffee to keep it at a drinkable temperature for a longer period of time. They came out of a Kickstarter project launched by Dave Petrillo and Dave Jackson in Tahoe City, California.
The Kickstarter project launched around March 27, 2011 and was fully funded three days later, even though the funding target didn't need to be met for thirty days. Production was established at Sherrill Manufacturing in Sherrill, New York. The team decided to continue with production in the United States, rather than moving to Mexico, as was their initial plan.
The project was at 300% of the target funding level by April 1, 2011. As of 9 April 2011[update], the project had raised $128,000 by 2200 backers, while the original project target was only $9500, and the dies for stamping were expected to cost $20,000.
The non toxic Paraffin wax has a melting point of 140 °F (60 °C). A similar concept using phase change materials, but integrated into the walls and bottom of a cup, had been invented by the Fraunhofer Institute for Building Physics two years earlier.
Effectiveness Of Joulies
Coffee Joulies are best used in an insulated vessel. The more efficient the insulation, the more effective Joulies will be. They are most effective in a vacuum thermos bottle or insulated cup with a lid (such as the often-used, foam take-away cups). Taking a thermos of coffee to work (or commuting, camping, fishing, etc.), to be consumed over a number of hours is an excellent and highly-effective use of Joulies.
Using Joulies in an open, ceramic coffee cup will bring the temperature down to a drinkable level without blowing on the beverage or using a spoon to cool it down. The benefit of keeping the coffee at a drinkable temperature is diminished because of the heat loss through the ceramic material itself and exposure of the coffee to the air.
A video has been released by the creators that shows the initial cooling effect, but ends shortly after that, failing to show the effect of keeping the beverage hot for significantly longer.
Some reviews show Joulies work while others have expressed doubts over the product's effectiveness. After doing some tests, they reported that the product does not work very well if at all.  Specifically it is stated that the promised effect, while existing, is "barely noticeable", especially when compared to adding other objects of similar heat capacity, thus being far from the creators' claims that the drink “will be ready to drink three times sooner and will remain hot twice as long.”
- "Coffee Joulies – your coffee, just right by Dave & Dave » Funding Goal Met, Keep It Up!! — Kickstarter". Kickstarter.com. Retrieved 2012-02-17.
- Robert H. Kent (2011-03-30). "Coffee Joulies – your coffee, just right by Dave & Dave » Broken Kickstarter, Blogs, 50 Backers and 1/3 of Goal Met After Just 2.5 Days!! — Kickstarter". Kickstarter.com. Retrieved 2012-02-17.
- Baber, Cassaundra (30 May 2011). "Coffee Joulies' young inventors bring new life to Sherrill plant". The Observer-Dispatch. Retrieved 31 May 2011.
- Wortham, Jenna (21 April 2011). "Online Help for Those Who Want to Make Tangible Stuff". The New York Times. Retrieved 21 April 2011.
- "Coffee Joulies – your coffee, just right by Dave & Dave » Saving the Silver City — Kickstarter". Kickstarter.com. Retrieved 2012-02-17.
- "Coffee Joulies Save you from Scalding Coffee". ABC News. Retrieved 13 April 2011.
- Gulezian, Lisa (1 April 2011). "Two entrepreneurs find cool idea for hot coffee". KGO-TV. Retrieved 9 April 2011.
- Buchanan, Matt (30 March 2011). "Cream, Sugar and Some Endo-Exothermic Phase Change Material for Your Hot Coffee?". Gizmodo. Retrieved 9 April 2011.
- "Phase change materials for the perfect cup of coffee". gizmag.com. 24 August 2009. Retrieved 28 May 2012.
- "Coffee Joulies - just the way Goldilocks likes it". Gizmag. 2011-03-19. Retrieved 2012-05-08.
- "Coffee Joulies - cool coffee faster". coffeejoulies. 2011-02-01. Retrieved 2012-05-28.
- "COFFEE TEMPERATURE REGULATOR". Cooks Illustrated. Retrieved 2013-03-29.
- Gibberish Is My Native Language (2012-02-05). "Coffee Joulies(tm) Beverage Cooling Beans Review | Gibberish Is My Native Language". Journal.drfaulken.com. Retrieved 2012-02-17.
- "Review: Coffee Joulies –". Marco.org. 2011-08-10. Retrieved 2012-02-17.
- "Coffee, tea, and Joulies - All this". Leancrew.com. Retrieved 2012-02-17.
- "Blog Archive » A Swift Kick in the Joulies". Jeff Ammons. 2012-01-10. Retrieved 2012-02-17.
- Coffee Joulies – Your Coffee, Just Right - Wired
- Coming Soon To Your Mug: Temperature-Regulating Coffee Widgets - Popular Science
- Coffee Joulies - just the way Goldilocks likes it - Gizmag
- Want to keep your drink hot? - Toronto Sun