If you’re shopping for coffee at the grocery store, “check the roast date, rather than the ‘best by’ date,” says Awan. With mass market roasters, the “best by” date can obfuscate the window in which coffee beans are at their best: about 4 days after roasting, when some, but not all, of the carbon dioxide has escaped from the beans. (Too much carbon dioxide captured within beans tends to create uneven extraction, as the gas escapes — this is what pre-infusing tries to counter. Conversely, too little carbon dioxide in the bean can lead to a loss of flavor.)
On August 27, 1930, Inez H. Pierce of Chicago, Illinois filed patent for the first vacuum coffee maker that truly automated the vacuum brewing process, while eliminating the need for a stove top burner or liquid fuels. An electrically heated stove was incorporated into the design of the vacuum brewer. Water was heated in a recessed well, which reduced wait times and forced the hottest water into the reaction chamber. Once the process was complete, a thermostat using bi-metallic expansion principles shut off heat to the unit at the appropriate time. Pierce's invention was the first truly "automatic" vacuum coffee brewer, and was later incorporated in the Farberware Coffee Robot.
That water is heated in a detachable reservoir that doubles as a kettle. This is a unique feature for a coffee maker, but one we ended up appreciating, especially for households with a mix of tea lovers and instant-oatmeal eaters alongside coffee drinkers. Fill the kettle up, lock it in place, and scroll the dial to the amount of coffee you want brewed. The machine is designed so that, even if you have more water in the kettle than you need, it will brew only the amount you specify. The one thing you actually have to measure with the OXO On 12-Cup is the grounds. Do that right, and it’s pretty much impossible to screw it up.
For many of us, the daily grind can't begin until we've had that first cup of piping hot coffee—so the right brewer is at the top of the list. The most basic coffee makers make at least a decent cup, but a little more money buys conveniences such as programmability, a thermal carafe to keep coffee hot longer, settings that let you adjust brew strength, and more.