A coffee machine is an electric, automatic brewing system typically used for making coffee. Before the invention and widespread use of electricity, different types of non-electric, coffee-making equipment were used. Many brands and models of coffee machines are now available for both household and commercial use. These coffee machines usually have outer coverings made of metal or plastic.
Commercial coffee machines typically are designed for constant use in restaurants and other food-service businesses. A coffee machine made for the home may only last a few years with heavy use, but most machines are fairly inexpensive to replace. Coffee machines usually have a water reservoir, a filter, brewing system, and a glass or ceramic pot. Some machines are basic, while others may have different features such as a clock and timer. These models allow coffee drinkers to prepare and program their machines to create a freshly brewed beverage at a time of their choosing.
It can be important to note that current electric coffee machines still brew on the basic concepts developed in the early- to mid-19th century. Percolation, in which water moves upward through a hollow cylinder through the coffee, dates back to early 19th century France. In the mid-10th century in England, the vacuum style of coffee machine was developed: a vacuum mechanism channels water from one pot to another. A tap controlled the flow of the prepared coffee for serving.
A modern coffee machine usually passes or drips water automatically through the grounds; this process is known as a drip brew. Water is first placed into the reservoir in the machine. A paper filter is typically used in many coffee machines. The coffee grounds are placed into the filter. When the machine is plugged into an electrical outlet, the automatic drip brewing process begins; ready-to-drink coffee is usually produced within minutes.
Automatic coffee machines usually feature a warming element so that the coffee in the glass pot will remain warm until it is needed. Home coffee machines typically brew between 10 and 12 cups at once. There are also mini coffee makers that brew only one or two cups at any one time. Many coffee machines are designed to sit on a countertop, but there are also models made to attach under kitchen cabinets in order to save space. Different models of coffee machines differ in the shape of paper filters they use; cone and round shapes of coffee filters are common.