It’s obvious, but easy to forget: If you don’t clean out your coffee machine’s carafe after each use with soap and water, you’ll always end up tasting a little bit of yesterday’s now-bitter brew. Thermal carafes need to be hand-washed, but all the plastic components of our top picks — brew baskets, lids, etc. — are dishwasher-safe if you keep them on the top rack.
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.
“I am a coffee snob, and one of my favorite things about traveling to Europe is their espresso and cappuccinos. A couple years ago, I bought a Nespresso Aeroccino machine for making froth and a stovetop Moka pot for making espresso; the system has worked fine, but the espresso can take awhile to make (around 5-8 minutes) and there’s definitely a learning curve to making good coffee with it. … [How] does this machine do [in comparison]? Stellar. Absolutely stellar. Once the water is in and it heats up, you flip up a lever, drop in the pod, and press the size button (espresso or lungo). Off it goes! Brewing is super quick and the espresso always comes out with a beautiful crema on top. My first drink was a cappuccino, and it was so much better than the ones I’ve been making with my Moka pot! …
It can take a little while to get to know the ins and outs of a new coffee maker. In CR’s labs, each drip coffee maker we test brews roughly 65 cups by the time our engineers are through with it. And brewing is just one of many aspects we look at. We test for handling and convenience, too, so you can choose a model that helps you sail through morning madness.