On August 27, 1930, Inez H. Pierce of Chicago, Illinois filed patent for 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, and was later incorporated in the Farberware Coffee Robot.
‡Pre-Infusing: Pre-infusing is a technique where the dry coffee grounds are initially saturated with hot water, allowing a “bloom” of carbon dioxide to escape. This 45-second(ish) process puts hot water into contact with more surface area around each ground throughout the brewing process, as it’s no longer competing with the escaping gas bubbles. It can improve the quality of the final product, since this more uniform contact creates a more even extraction. It’s a feature that six of the 10 pots we tested incorporated into their designs — as well as all four of our top picks.
Bunn-O-Matic came out with a different drip-brew machine. In this type of coffeemaker, the machine uses a holding tank or boiler pre-filled with water. When the machine is turned on, all of the water in the holding tank is brought to near boiling point (approximately 200–207 °F or 93–97 °C) using a thermostatically-controlled heating element. When water is poured into a top-mounted tray, it descends into a funnel and tube which delivers the cold water to the bottom of the boiler. The less-dense hot water in the boiler is displaced out of the tank and into a tube leading to the spray head, where it drips into a brew basket containing the ground coffee. The pourover, water displacement method of coffeemaking tends to produce brewed coffee at a much faster rate than standard drip designs. Its primary disadvantage is increased electricity consumption in order to preheat the water in the boiler. Additionally, the water displacement method is most efficient when used to brew coffee at the machine's maximum or near-maximum capacity, as typically found in restaurant or office usage. In 1963, Bunn introduced the first automatic coffee brewer, which connected to a waterline for an automatic water feed.
The Moccamaster isn't for everyone. Handmade in the Netherlands, it costs around $300—and would never win an award for value. It lacks a programmable timer, and it was also bit more difficult to set up than the rest of the coffee makers—in fact most were ready to go right out of the box. But a quick look at the instruction diagram should clear up any confusion, and the end result is well worth the effort.
The moka pot is most commonly used in Europe and in Latin America. It has become an iconic design, displayed in modern industrial art and design museums such as the Wolfsonian- FIU, Museum of Modern Art, the Cooper–Hewitt, National Design Museum, the Design Museum, and the London Science Museum. Moka pots come in different sizes, from one to eighteen 50 ml cups. The original design and many current models are made from aluminium with bakelite handles.
These organizations consider how long it takes you to brew the coffee, the social impact of the coffee maker, as well as the roasting ability of the coffee maker. The best coffee maker will be BPA free and certified. An SCAA certified coffee maker, for example, will be able to deliver water at optimum temperatures throughout the whole brewing process, without compromising the integrity of the coffee at any point.