individual or multi-serving portions. In food service businesses, pods and capsules used with automatic brewing can help to provide consistency of product strength and flavor for customers. Paper coffee pods such as those used in Easy Serving Espresso Pod or Senseo machines have the benefit of being a fully biodegradable product that can decompose naturally, while plastic and metal capsules such as those used in Keurig or Nespresso machines either are not recyclable, or require additional processing to separate the plastic/metal container from the organic waste products. Many capsule machines specifically warn the user to not disassemble the machine or put their fingers inside the capsule receptacle, as the devices commonly use sharp razor-edge tubes or prongs for piercing the coffee capsule during use. Different single-cup systems are not interchangeable; some systems force machine owners to buy capsules from a single company (usually the patent owner), locking the machine owner into a single source of coffee. Coffee pods are made by a variety of manufacturers and are interchangeable between brand of pod and model of pod brewer most of the time. Environmental impact Environmental activists have said that single-use coffee pods are harmful, as they are often composed of a mix of plastic, aluminium, and organic material (the used coffee) which makes them difficult to recycle. In early 2016 the German city of Hamburg banned coffee capsules from state-run buildings on environmental grounds. There are some capsules that are plant-based and that can be compostable as bio-waste. See also Coffee service Coffee wars References Retail packaging