The OXO On 12-Cup feels high-tech without being high maintenance. It’s beautifully constructed, with silicone gaskets, a stainless steel carafe, and sturdy-feeling plastic. But let’s go ahead and get its biggest downside right out there in the open. Of the 10 machines we tested, it took the longest to brew eight cups of coffee — nearly 15 minutes. It heats its entire reservoir of water to temperature before a drop touches the grounds, and if you’re jonesing for a full pot to start off your day, that wait is going to feel like a lifetime. This was particularly noticeable considering four of the machines we tested brewed the same amount of coffee in less than half that time. The Bunn BTX-B Velocity Brew could do it in three minutes flat.
The Bonavita is a simple, compact machine (about 12 inches x 12 inches) for only $190, and it makes coffee that ranked in the top three in our taste test. Its philosophy seems to be “everything you absolutely need, nothing you don’t.” That means it’s SCAA-certified for water temperature and brew times, boasts pre-infusion capabilities, and has a flat-bottom filter basket that extracts grounds evenly. That’s it.
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.