Bests & Worsts Reviews from Amazon

I recently purchased a set from Coffee Joulies, and had really high hopes. PCM technology has vastly improved home insulation and other areas, and I was excited to have this technology work for my morning coffee. To start off, I read all the directions and used them as directed, and I never add cream. In short, they - make your coffee cooler slightly faster (1.5x in my testing versus 35x advertised) - have negligible difference on drinkable range (1.06 in my testing versus 1.9x advertised) - look very shiny and seem well made - have reasonable customer service and accept returns, the reason for the second star I have uploaded my test data in the product images for anyone interested. These match well with another reviewer's data from marco.org. DO NOT fall for these, they are purely a gadget designed to play to human emotion, but make little to no difference on actual coffee temperature. Go buy a thermos if you want your coffee to stay warm longer, it will make a much larger difference. These are likely somewhat more effective in thermoses, but they are not useful in conditions that matter when drinks cool faster. The full story is below if you are interested. -------------- The first time I used them, I put them directly in the piping hot Dunkin Donuts cappuccino, which I often burn my mouth on. I read the advertisement that says in an insulated thermos, a 180 degree drink was safe to sip in 2 minutes 25 seconds, so I waited 5 minutes. I took a small sip and burned my tongue, not a good start. I figured maybe since they took longer to cool, it would stay hot longer. By the time I got to my desk (~40 minutes), it was already cold. Usually, it is still luke warm. I figured the cappuccino at around 180 degrees wasn't enough to melt all the PCM, so I made tea using boiling water. Still no noticeable effects. I decided to see with data if I was just imagining this, or if they really were making little to no difference. I took their test data from their website, and scaled it to fit in my mug rather than their insulated thermos. Using my calibrated thermocouple, I took data from a control test and the mug with the scaled amount of Joulies. The drink was safe to sip slightly sooner, but the drinkable range was almost identical (1.06x longer using the Joulies). That is only a 15 second difference! I decided maybe I have defective units and emailed customer service. The response I received was "It seems like you have been using the joulies properly. For some people it achieves the desired effect and for others it doesn't. Sorry that you were not happy with your Coffee Joulies." They have not even attempted to disagree, or backup their product. They are well aware of the non-effectiveness in real world situations. I will be sending them back for a refund, but I am still out shipping.