The principle of a vacuum brewer was to heat water in a lower vessel until expansion forced the contents through a narrow tube into an upper vessel containing ground coffee. When the lower vessel was empty and sufficient brewing time had elapsed, the heat was removed and the resulting vacuum would draw the brewed coffee back through a strainer into the lower chamber, from which it could be decanted. The Bauhaus interpretation of this device can be seen in Gerhard Marcks' Sintrax coffee maker of 1925.
Some machines come with all the accessories you need to make espresso, but others don't. Check to see if your machine includes any accessories before you buy them. You will need a grinder to have freshly ground espresso, a milk frother or a milk frothing pitcher if you like foamy milk for cappuccinos or lattes, and a tamper to press down the coffee grounds before you make espresso. We explain why you need each one and recommend which ones to buy below:
This Good Housekeeping Seal star features an all-black body, a 12-cup glass carafe, a reusable filter and a backlit LCD screen with digital touchpad controls. You can program the clock to automatically brew coffee in the morning. It'll make a hot pot very quickly, but drink up — the keep warm feature didn't keep the coffee as warm as other models in our tests.
CR’s take: This unassuming, inexpensive Hamilton Beach coffee maker might be easy to miss, but it can brew a mean cup of joe at a fantastic price. In a basic black-plastic finish, it has the essentials—it’s programmable and offers auto-shutoff—and it offers solid brew performance in a decent time frame (10 minutes). Hamilton Beach machines even earned a Very Good rating for predicted reliability. At around $25, this simple model will get the job done.
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.
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.