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.
Making espresso in my old, classic Italian-style Moka machine takes about 10 to 12 minutes — and a bunch of elbow grease. My drip-maker for a classic American cup of joe takes even longer. My brewing cone for pour-over coffee requires me to boil water — and it can't make espresso. And my French press needs about 20 minutes to steep. Plus, it makes too much coffee and I find it's best reserved for fancier brunches.
A drip coffee system is far superior to an instant coffee maker. For some, the smoother, less intense taste and aroma of a drip coffee system is a lot more palatable than the bitter coffee that tends to be produced by a French press. Not only that, but a drip coffee system is versatile – you can ground up your coffee beans to use in your system, and you can also buy premade blends.
For example, if your coffee tastes a bit salty or sour, the grounds are under-extracted, which can be remedied by a finer grind. But what if only some of your grounds are too coarse, and others are too fine – and maybe some are just right? Having uniform grind size throughout your brew basket makes it easier to isolate and adjust this variable in order to get the level of extraction you want. The only way to achieve that is with a burr grinder. Miller — as well as a handful of our other experts — recommends the Barazata Encore Coffee Grinder ($129).
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.