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.
The machine itself is large, but not as monstrous as some of the other grinders I tested. It's also very bottom-heavy, which makes it feel more durable than other machines and means it won't rattle all over your counter while grinding. The heavy-duty translucent plastic collection cup generates less static cling than the glossy clear plastic cups I tested, and the chute that connects the burrs to the cup collects less debris than other models. Cleaning is simple: Just remove the top burr and use the included wire brush to remove residual grounds.
If tinkering is what you’re most excited about, we recommend the Behmor Brazen Plus Customizable Temperature Control Brew System. This is a drip machine that takes its job seriously. It performed the very best in our out-of-the-box taste testing, but still gives you the opportunity to play around with different variables, from water temperature to pre-infusion times. At around $200, it’s on-par with the OXO 9-Cup price-wise, but is definitely not as nice to look at or use, with a tall, bulbous body, squat carafe, and an eight-button programmable interface that reminded us of a digital alarm clock.
One of the many issues with other coffee makers is that the brewing process is inconsistent, with temperature fluctuations that can potentially affect the acidity, aroma, and final flavor of your beverage. The OXO On Barista Brain Coffee Maker is fixed with an intelligent microprocessor that monitors ambient temperatures throughout the brewing process.
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.