How to Choose a Coffee Machine For Pods Pod machines operate by reading the barcode on the top of the pod (which is actually an un-sealed disc of pre-dosed ground coffee that is pressed between two layers of filter paper). Simply insert it into the machine and press the button. https://coffeee-uk71798.59bloggers.com/28746160/what-the-10-most-worst-best-pod-coffee-machine-failures-of-all-time-could-have-been-prevented