Size aside, the beans are a beautifully designed product. They are smooth and feel solid in your hand. I found myself wanting to hold them like worry stones when they weren't in my mug. As far as I could tell, the beans also gave no perceptible flavor to the coffee, metallic or otherwise.
I am the true target audience for a product like this. I wait for my coffee to cool before taking the first sip and then never manage to drink the whole cup before it cools. Theoretically, the joulies should cool the coffee to perfect sippable temperature (140°) within a few minutes and then hold that temperature for longer than it would otherwise. Exactly what I need.
I found that the joulies definitely cooled the coffee down to a nice hot-but-not-scalding temperature very quickly. Less perceptible was their effectiveness at holding the temperature. My coffee really seemed to cool in about the same time that it does without the joulies. My study was admittedly observational rather than scientific, but I expected much more dramatic results from the joulies in this area.
My friends who own the joulies I was test-driving say that the cooling time can really depend on how hot the coffee is to begin with. The hotter the coffee, the more energy the joulies will absorb and the longer they'll be able to hold the coffee's temperature. The joulies make less of a difference in a cup that is already close sipping temperature.
Additionally, joulies work better in a travel mug (which is already insulated) than in a ceramic mug and increasing the number of joulies can help with performance. The coffee also cools more quickly the less there is in the cup. Regardless, my friends say they re-heat coffee far less frequently using the coffee joulies than they did before.
My take-away experience was that these coffee joulies have a lot of potential, especially for coffee addicts and slow-sippers like me. After talking with my friends, I also think that it takes a little trial and error before figuring out how to use the joulies most effectively for your coffee-drinking habits. My Saturday morning couch trial left me feeling curious but not overly wowed, while my friends use the joulies every day and swear by them.
Have you tried these joulies? What's your experience?
• Find Them! Coffee Joulies, $50 for a set of five
(Image: Emma Christensen)