An electric drip coffee maker can also be referred to as a dripolator. It normally works by admitting water from a cold water reservoir into a flexible hose in the base of the reservoir leading directly to a thin metal tube or heating chamber (usually, of aluminum), where a heating element surrounding the metal tube heats the water. The heated water moves through the machine using the thermosiphon principle. Thermally-induced pressure and the siphoning effect move the heated water through an insulated rubber or vinyl riser hose, into a spray head, and onto the ground coffee, which is contained in a brew basket mounted below the spray head. The coffee passes through a filter and drips down into the carafe. A one-way valve in the tubing prevents water from siphoning back into the reservoir. A thermostat attached to the heating element turns off the heating element as needed to prevent overheating the water in the metal tube (overheating would produce only steam in the supply hose), then turns back on when the water cools below a certain threshold. For a standard 10-12 cup drip coffeemaker, using a more powerful thermostatically-controlled heating element (in terms of wattage produced), can heat increased amounts of water more quickly using larger heating chambers, generally producing higher average water temperatures at the spray head over the entire brewing cycle. This process can be further improved by changing the aluminum construction of most heating chambers to a metal with superior heat transfer qualities, such as copper.
CR’s take: For $80, this Mr. Coffee 12-cup drip brewer is surprisingly stylish. Its airy design sets it apart from the blocky shapes common to the category. This model earns a rating of Very Good in CR’s brew-performance tests and makes a full pot in just 9 minutes. It offers brew-strength control, programming, and a permanent coffee filter. With its performance and striking appearance, you might not mind having it out on the counter—especially in a kitchen with a stainless fridge and range.
This grinder produced the most even grounds out of all the machines I tested, and its range of output is all-encompassing. The coarsest setting produces large flakes, while the finest setting produces puffy grounds akin to powdered sugar—perfect for Turkish coffee. In between, I was quickly able to find the ideal settings for my Hario Woodneck, Aeropress, and even mason jar cold brew.
Prior to the introduction of pre-measured self-contained ground coffee filter rings, fresh coffee grounds were measured out in scoopfuls and placed into the metal percolator basket. This process enabled small amounts of coffee grounds to leak into the fresh coffee. Additionally, the process left wet grounds in the percolator basket, which were very tedious to clean. The benefit of the Max Pax coffee filter rings was two-fold: First, because the amount of coffee contained in the rings was pre-measured, it negated the need to measure each scoop and then place it in the metal percolator basket. Second, the filter paper was strong enough to hold all the coffee grounds within the sealed paper. After use, the coffee filter ring could be easily removed from the basket and discarded. This saved the consumer from the tedious task of cleaning out the remaining wet coffee grounds from the percolator basket.