These machines automatically grind the coffee, tamp it, and extract the espresso shot. The operator only has to fill the bean hopper and, if the machine is not connected to a water line, add water to a reservoir. Some models contain an automated milk frothing and dispensing device. Super-automatic machines take away the ability to manually tamp and grind the coffee, which may affect the quality of the espresso.
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.
“Self-identified coffee snob. Couldn’t be happier. Easy to operate, functions as advertised, instructions are clear. The metal filter included does what it needs to do. I recommend a relatively coarse grind (imagine the feel of cornmeal) with the metal filter to get the full flavor of the coffee. If you’re a bit of a coffee snowflake (no disrespect intended) and don’t like the ‘mud’ at the bottom of the cup, you should stick with the paper filter. Either way, the coffee maker itself does the job nicely.”
The method for making coffee in a percolator had barely changed since its introduction in the early part of the 20th century. However, in 1970 General Foods Corporation introduced Max Pax, the first commercially available "ground coffee filter rings". The Max Pax filters were named so as to compliment General Foods' Maxwell House coffee brand. The Max Pax coffee filter rings were designed for use in percolators, and each ring contained a pre-measured amount of coffee grounds that were sealed in a self-contained paper filter. The sealed rings resembled the shape of a doughnut, and the small hole in the middle of the ring enabled the coffee filter ring to be placed in the metal percolator basket around the protruding convection (percolator) tube.
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.
The tall tower is fixed on a rectangular base, with a water tank that looks something akin to a trapezoid. The hard plastic funnel allows your favorite paper filters to fit inside of it. It is recommended that you use type 4 paper filters, however. You also have the option to use permanent gold filters if you want to move away from reoccurring costs.
If you don’t have the time or want to build a highly customized taste for your espresso mixes and just want a great tasting cup of espresso, super-automatic espresso makers are going to be your best bet. While you do give up some of the control you have over the final product, a super-automatic espresso maker automates almost all of the process for you, meaning that you can just get a great shot of espresso without having to do any extra work. This makes it perfect for people on the go or who prefer convenience over control.
The simplicity starts with its design: a single button with a scrolling dial underneath an LED interface. That button is the only one on the entire machine. With it, you set the time, set the water temperature, set how many cups you want brewed, and when you want the brewing to start. It takes a second to get the hang of it, but we were impressed with how intuitive it is — a stark contrast to a machine like the Moccamaster KBT 10-Cup Coffee Brewer, which had so many extra pieces, it required constant consultation of the instruction manual.
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.
‡Pre-Infusing: Pre-infusing is a technique where the dry coffee grounds are initially saturated with hot water, allowing a “bloom” of carbon dioxide to escape. This 45-second(ish) process puts hot water into contact with more surface area around each ground throughout the brewing process, as it’s no longer competing with the escaping gas bubbles. It can improve the quality of the final product, since this more uniform contact creates a more even extraction. It’s a feature that six of the 10 pots we tested incorporated into their designs — as well as all four of our top picks.
Whole bean coffee that you grind yourself is preferable to pre-ground, too. The bean’s exterior traps and protects all of the delicate, volatile, and water-soluble oils that give coffee its flavor. As soon as you break the protective shell, it’s easy for the flavor to get contaminated, and much of the aroma escapes as soon as the oils are exposed to air.
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.