Back when Coffee Joulies were just a Kickstarter project, I felt like these heat-absorbing beans that promised to cool your coffee to drinkable temperature and keep it there could turn into either an easily-dismissed gadget or a gimmick. A few weeks ago, I finally had a chance to try them for myself.
The beans are about the size of a soup spoon and bigger than I expected.This is both good because there's no risk of accidentally swallowing them (as some people initially feared), but also means that they take up a fair amount of coffee cup real estate. The size is more noticeable in a smaller ceramic mug than a larger travel cup. A travel cup also prevents the beans from hitting your teeth when you get toward the bottom of the cup.
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
More Coffee Joulie Reviews:
• SCAA 2011: A First Look at Coffee Joulies from Sprudge.com
• Review: Coffee Joulies from Marco.org via BoingBoing
Related: Simple Invention: Reusable Mesh Coffee Strainer
(Image: Emma Christensen)
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I bought these. I was sorely disappointed. I didn't find them to keep my coffee any hotter than normal.
Another website did a more scientific test with a thermometer, and basically confirmed that the joulies only "work" when used with a thermos or insulated mug.
In fact, on the instructions that came with the joulies, they recommend using an insulated mug.
Which begs the question: why spend $50 on these when a thermos or insulated mug works just as well?
Honestly, I feel like the product made a lot of promises, and didn't come close to delivering.
@agrayson I think I read the same study.
They're pretty...but not $50 pretty.
This seems utterly useless to me, especially for the price. How pretentious do you have to be to merit spending fifty big ones on something that will make your coffee a "sippable temperature".
That's what AIR is for. Also, a grain of patience. Just a grain.
They'd be a great gift if they weren't so ($#&*(&$?* expensive.
"That's what AIR is for."
or a spoon. Leave a metal spoon in your coffee or tea when you first make it and it will cool down faster. Take the spoon out when the drink is cool enough to drink.
$50!? They'd make a cute stocking stuffer if they were $5, but I certainly wouldn't spend more than that on such an unnecessary frivolity.
We bought them off kick starter and were disappointed with them. Sure it cools it down a little faster but did not keep our coffee warm or hot at all no matter what it was in and how we prepared them. =( Hopefully the second run will be improved.
I did the kickstarter too like @TheWholesomeHome, pretty damn disapponted myself. Used them in my Contigo Autoseal Stainless Steel thermos and it definitely helped it get to drinkable temp faster but staying warmer for longer it definitely did not.
As for @asmallcontempt's comment as for that's what air is for. That's a good one but some people just want to enjoy their coffee to wake the hell up and not get burned man lol. But for the price, totally agree with you, in retrospect, totally wouldn't have bought it.
Out of curiosity, agrayson, did that study compare thermal mug + joulie to thermal mug alone? Seems like the mug is doing all the heavy lifting in that equation...
This is the other review everybody is probably referring to.
What makes them interesting to me (at least in theory) is NOT that they cool down the coffee, but rather that they are supposed to then hold the coffee at that "perfect" temperature.
I can certainly wait for my coffee to cool on its own. But once my coffee has cooled to "drinkable" temperature, it then gets cold faster than I can manage to drink it. So I am far more interested in the "keeping coffee warm" aspect of these little guys.
I second (third?) Marco's review. The science behind them is sound. Phase changing substances absorb heat but do not change temperature. However, what is lacking is size. You need to have even larger joulies to absorb a reasonable about of heat.
You are better off pouring your coffee between two cups to bring down the temp and then using a GOOD vacuum flask/mug (I prefer Contigo) to keep it there.
my husband also bought these off kickstarter and was sorely disappointed (he tried them in the mug and thermos). Brings it down to temp, but definitely does not help hold the temperature.
several years ago I went out and bought a Brugo Mug after hearing about how it cooled off coffee. It wasn't really coffee that was an issue it was Americanos because usually the water is hotter than the espresso itself. It costs $20 and is basically a nifty little travel mug. http://www.brugomug.com/
Contrary to most reviewers' experiences, my husband also invested in these through Kickstarter. He takes hot, freshly brewed coffee in an insulated travel mug (Oxo) to work each morning. He uses 4-5 Joulies and finds that they keep the coffee hot as he sips it through the morning. Overall, the Joulies were a good buy for something he uses almost daily.
Are you heating the Joulies in hot water before using them? When I do that, they provide me with long term warmth. Yes, I prefer a travel mug too, but I also think it was a good Kickstarter investment for me.
I second on @MaritS. They are more effective if you preheat them. Same is true with my thermos travel mug. If I pour hot water and wait till coffee brews, I can get 5+ hours of hot coffee without these noisy bulky fancy looking beans. I am also worried, they might damage mug while riding and sipping.
Hey everyone, east coast Dave here. Glad to hear from our backers who are enjoying their Joulies. In the ceramic mug, Joulies are intended to get you to a drinkable temperature sooner, but will only hold that temperature for a few minutes longer since ceramic mugs lose heat so fast. (this is perfect for some people, not for others) Our claims of cooling three time faster and hold the temp for twice as long are easily exceeded in containers with lids. Here is some independent research from some engineering students at Purdue: http://goo.gl/5Ex5k and our own data here: http://twitpic.com/63wcps
What Emma and her friends found was that it does take a little bit of trial and error to get Joulies to perform to their max. But, when you get the hang of it you are rewarded with the kind of performance that makes you want to use them every day.
For any of our customers who aren't feelin' it, we will do anything we can to make sure you're happy, even if that means sending in your Joulies for a refund :-)
I have some very cool smooth rocks that would do the same thing. They came from the beach, so not only didn't I spend $50, but I had a nice walk too.
I bought a set of Joulies before reading this article. They made no perceivable difference in maintaining the heat of my coffee, even in a thermal mug. In addition, they are large, heavy and added an odd taste. I tried them once in a ceramic cup and once in a thermal cup and was disappointed both times. I just wrote to the seller to request a refund. For $55 I expected something terrific. Unfortunately, Joulies didn't deliver for me.