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.
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.
CR’s take: Though this Bialetti lacks typical drip-machine features such as programming and brew-strength control, it more than compensates with a Very Good rating in our brew performance test and a crisp 8-minute brew time. If you’re the type who sometimes prefers a morning shot of espresso to a cup of joe, this twofer—drip machine beside espresso maker—may be for you. It features a built-in milk frother, a permanent coffee filter, and auto-shutoff. CR does not yet have enough survey data on Bialetti machines to rate them on reliability and satisfaction, but when we do, we’ll add that info to our ratings.
The K575 Single-Serve K-Cup Pod Coffee Maker combines impressive design, and top-of-the-line technology into one powerful package – the ultimate coffee maker. With customizable settings including strength and temperature control, and with the most brew size options – any size from 4 to 30 oz. – you can brew the perfect cup, mug, or carafe of your favorite beverages at the touch of a button. Choose from hundreds of delicious varieties from the brands you love, all easily brewed thanks to...
CR’s take: Our highest-rated drip brewer with an insulated, thermal carafe, the Ninja Bar Brewer CF085 has plenty to recommend it. CR’s testers find that it offers superb brew performance and is very easy to use. In our member surveys, Ninja drip coffee makers received an Excellent rating for owner satisfaction. (We don’t yet have enough data to judge reliability.) This model has a full suite of features, including an unusual over-ice brew mode for making iced coffee. Ninja claims its thermal carafe will keep coffee hot for 2 hours, and the machine comes with a milk frother and a standalone French-press brewer. These features come at a price, of course; the Ninja Bar Brewer is the second most expensive model on this list.
It’s not that cone filters won’t make a great cup of coffee — the OXO On 9-Cup still ranked fifth out of 10 in our taste test. But flat bottoms generally allow for the grounds to be more evenly extracted and increase the coffee’s flavor. (It’s no coincidence our other three recommendations have flat-bottom brew baskets). You may have to do a little more tweaking to get this coffee maker’s brew to the best it can be, and that’s the other reason we like the 12-cupper more. This smaller version doesn’t let you tinker with water temperature.
CR’s take: If you’re an aficionado of fresh ground coffee, this Black+Decker is the brewer to buy. As the name suggests, the Mill & Brew goes that extra mile, grinding whole coffee beans just before brewing. As a result, the machine is capable of making a great pot of coffee. Made of plastic with stainless steel accents, this model is easy to use and to clean, earning a Very Good rating in our convenience tests. It allows you to adjust brew strength, and it’s programmable, so you can set it to grind and brew just before you wake up.