I'm one of the original kickstarter contributor of coffee joulies. For me, it does work. Coffee came out of my keurig brewer are at drinkable temperate immediat

I'm one of the original kickstarter contributor of coffee joulies. For me, it does work. Coffee came out of my keurig brewer are at drinkable temperate immediately. But I'm not sure if it can hold temperature longer. I guess I'm just using it a ice cubes without diluting the coffee and also not accidentally making it too cold