The Mr. Coffee Optimal Brew coffee maker System has a highly modular design, with its rectangular water reservoir easily sliding in and out of the chassis. For those who only want a cup of basic coffee, you will find that the Mr. Coffee Optimal Brew coffee maker System will do that very well – its "brew now" button is found on the front of the machine.
This testing was designed to highlight the difference in how each machine extracted its coffee grounds. Remember, extraction is tied to water temperature, how long the grounds had to steep, and how evenly that water is distributed in the brew basket. (Depending on how the machine distributes the water and the shape of the basket, any particular ground may or may not receive the same amount of time in contact with water — thus any individual grind may be over-extracted, under-extracted, or just right.) Properly extracted grounds would have a balance of notes and aromas, from slight hints of acid to a pleasant amount of bitterness.
There were lots of innovations from France in the late 18th century. With help from Jean-Baptiste de Belloy, the Archbishop of Paris, the idea that coffee should not be boiled gained acceptance. The first modern method for making coffee using a coffee filter—drip brewing—is more than 125 years old, and its design had changed little. The biggin, originating in France ca. 1780, was a two-level pot holding coffee in a cloth sock in an upper compartment into which water was poured, to drain through holes in the bottom of the compartment into the coffee pot below. Coffee was then dispensed from a spout on the side of the pot. The quality of the brewed coffee depended on the size of the grounds - too coarse and the coffee was weak; too fine and the water would not drip the filter. A major problem with this approach was that the taste of the cloth filter - whether cotton, burlap or an old sock - transferred to the taste of the coffee. Around the same time, a French inventor developed the "pumping percolator", in which boiling water in a bottom chamber forces itself up a tube and then trickles (percolates) through the ground coffee back into the bottom chamber. Among other French innovations, Count Rumford, an eccentric American scientist residing in Paris, developed a French Drip Pot with an insulating water jacket to keep the coffee hot. Also, the first metal filter was developed and patented by French inventor.
Our brew-performance tests measure the brew temperature and contact time (how long water stays within a sweet spot of 195° to 205° F for brewing). We measure concentration using a refractometer, a device that measures the amount of coffee dissolved in each brew. Our convenience tests look at how easy it is to set timers, fill the reservoir, clean the machine, and more. And for the first time, we’re incorporating predicted reliability and owner satisfaction ratings into the new Overall Score for each model. We determine these ratings for each drip coffee maker brand using survey data collected from thousands of CR members.