The OXO is SCAA-certified, so we knew going in that it would heat water to the right temperature range and let coffee brew for the right amount of time. But what really sold us on the OXO was how its scrolling dial made even that customizable. Assuming you want to bring the extraction down a touch for lighter, subtler coffee, you can lower the water temperature with a twist of the dial. Likewise, if you want a slightly more robust aroma from your brew, you can increase the water’s temp the same way.
Some machines use a single boiler kept at steaming temperature, but water for brewing is passed through a heat exchanger, taking some heat from the steam without rising to the same temperature. Although the water for brewing remains at a lower range than that required for steaming milk, it is still too hot for proper coffee extraction without first cooling; thus this type of machine requires a cooling flush of 4–6 seconds prior to the first espresso pull. Once the machine is dialed into the proper temperature, as many shots can be pulled as required without refreshing. However, if the user leaves the machine idle again for some period, the flushing process will need to be repeated. The HX variety is found in many mid-range machines and many users install thermometers to assist them is dialing in correct temperatures. There is some controversy as to the temperature stability of the brewing water, since it is indirectly converted from steaming temperature to brewing temperature, rather than kept at a brewing temperature.
Certified by the SCAA and SCAE, this coffee maker exceeds the stringent quality control guidelines set forth by international coffee organizations. The inventor of this coffee maker, Gerard C. Smit has dedicated his life to creating coffee makers that do away with planned obsolescence, ensuring that this model – and every following model – is long-lasting, reliable, and energy-efficient.
Pierce's design was later improved by U.S. appliance engineers Ivar Jepson, Ludvik Koci, and Eric Bylund of Sunbeam in the late 1930s. They altered the heating chamber and eliminated the recessed well which was hard to clean. They also made several improvements to the filtering mechanism. Their improved design of plated metals, styled by industrial designer Alfonso Iannelli, became the famous Sunbeam Coffeemaster line of automated vacuum coffee makers (Models C-20, C-30, C40, and C-50). The Coffeemaster vacuum brewer was sold in large numbers in the United States during the years immediately following World War I.
The Breville is technically a semi-automatic espresso maker, since it requires you to dose and tamp your own shots, but we found it more forgiving than true automatics. The Breville’s dual-wall filter baskets (in addition to two standard single-wall baskets) add extra pressure, providing a little forgiveness for beginners’ mistakes in either grinding the beans or tamping the shot.
Once you start brewing, it makes a really, really good pot of coffee. Our taste test revealed the OXO On 12-Cup coffee was “dark and strong” and appealed to the more traditionalist coffee palates. The great flavor comes from the brewing process. The OXO machines have wide shower heads with multiple ports through which water streams, dispersing it evenly throughout the brew basket. Lots of other coffee makers spout water through just one hole, or through shower heads with a smaller radius, which can increase the chances of uneven extraction.
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.