Unlike a typical coffee and espresso machine, Nespresso machines are designed to only be used with Nespresso-compatible capsules. This being said, it is not recommended to use your own coffee grounds in your Nespresso machine. Some third-party retailers offer refillable capsules for Nespresso machines, but use them at your own risk. Because they are not verified by Nespresso, use of these capsules could gum up or damage your machine.