A single-serve coffee container is a method for coffee brewing that prepares only enough coffee for a single portion. Single-serve coffee containers can both reduce the time needed to brew coffee and simplify the brewing process by eliminating the need to measure out portions, flavorings, and additives from large bulk containers. They can also help to keep the unused product fresher by individually packaging portions separately without exposing the entire supply batch to air and light. Paper coffee pods can be functionally identical to plastic and metal coffee capsules, if the paper pods are individually sealed in separate bags. At the same time, the disposable single-use products add to the global waste production. Variations Several different systems exist: Coffee pods or pads are pre-packaged ground coffee beans in their own filter. A coffee capsule differs from a coffee pod in that the coffee is packed in a plastic or aluminum package instead of a paper filter, and it is usually designed for use with a single brand or system and is therefore not interchangeable with other systems. A patent on the Nespresso system expired at the end of 2012, and there are now rival capsules available for the Nespresso system. A variation, coffee bags, were developed to provide the convenience of instant coffee but maintain the flavor of brewed coffee. Modeled after tea bags, they consist of a gauze bag containing a mixture of instant coffee and finely ground roast coffee, which is to be steeped in hot water for approximately three minutes. Coffee (filter) disks or ground coffee filter rings are a ring-type variant of coffee bags made of coffee filter paper containing ground roast coffee for use in coffee percolators, which otherwise use permanent filters made out of metal or porcelain. One of the first companies to offer them was General Foods Corp. with their "Max-Pax" filter rings. Comparison of systems The plastic and metal coffee capsules typically are used in a non-removable receptacle on the brewing device. The capsules have an outer ring or rim that stays dry during use, allowing for removal and disposal after use without getting the user's hands wet or sticky. Handling of a used moist coffee pod is not necessary if the brewing device has a removable filter tray. This tray is removed after brewing and inverted to eject the used coffee pod. Coffee pods, bags, and capsules can be sized for