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.
Water quality also plays a massive role in the way your coffee tastes. As we discovered in our review of the best water filters, water isn’t tasteless. Total dissolved solids (TDS) are what give “good tasting” water its sweetness — in fact, the SCAA recommends water with 150 milligrams per liter of TDS to brew coffee. (Want to check your water? A TDS reader is only about 15 bucks.)
“Last night was a perfect test of the single-cup concept. I had already programmed and prepped my 3 a.m. standard coffee brew, however, I still wanted a cup of coffee. I switched over to the single cup and brewed my cup, then switched back and pressed the program button to ensure it would still brew the main pot at 3 a.m. Worked like a charm!! Before, I would have had to brew the entire eight cups that were ready, toss out most of it, and set up my morning brew all over again.”
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.