Vacuum Coffee Maker

   

    A lot of coffee brewing devices became popular during the 19th century, some of them relying on vacuum principles to operate. The Napier Vacuum Machine, invented in 1840, was an early example of this type. While generally excessively complex for everyday use, vacuum devices were prized for producing a clear brew, and were actually quite popular up until the middle of the 20th century. 

    The principle of a vacuum brewer was to heat water in a lower vessel until expansion forced the contents through a narrow tube into an upper vessel containing ground coffee. When the lower vessel was empty and sufficient brewing time had elapsed, the heat was removed and the resulting vacuum would draw the brewed coffee back through a strainer into the lower chamber, from which it could be decanted.

    On August 27, 1930, Inez H. Pierce of Chicago, Illinois invented the first vacuum coffee maker that truly automated the vacuum brewing process, while eliminating the need for a stove top burner or liquid fuels. An electrically-heated stove was incorporated into the design of the vacuum brewer. Water was heated in a recessed well, which reduced wait times and forced the hottest water into the reaction chamber. Once the process was complete, a thermostat using bi-metallic expansion principles shut off heat to the unit at the appropriate time. Pierce’s invention was the first truly "automatic" vacuum coffee brewer.

    Pierce’s design was later improved by U.S. appliance engineers Ivar Jepson, Ludvig Koci, and Eric Bylund in the late 1930s. They altered the heating chamber and eliminated the recessed well, which was hard to clean. Their improved design of plated metals, styled by industrial designer Alfonso Iannelli, became the famous Sunbeam Coffeemaster line of automated vacuum coffee makers.