"Only about 30 percent can be extracted, but you only want a percentage of what's available. If you get 18 to 22 percent, it's well extracted and theoretically tastes good," Schroeder says. "When you hit the marks on strength and extraction, it gets exciting."
To get this percentage, he plugs the weight of the grounds and water, and the TDS percentage into his VST CoffeeTools app, which gives him the extraction numbers. He started with a head-to-head test with the Oxo single cup and his own Kalita pour-over dripper, discovering changes he wanted to make in both.
He then made tweaks, particularly making the grind size larger for the Oxo. Soon, he started hitting the marks, and was able to do it with two of his coffees: Sisters Micro Lot from Guatemala and Buna Boka from Ethiopia. He tested them in the refractometer, hitting 1.38 TDS for the Ethiopian and 1.40 and for the Guatemalan, with extraction percentages of 21.4 for the Ethiopian and 21.74 for the Guatemalan.
I felt rather pleased with myself, bringing this $170 interloper home coffee maker into the fancy coffee shop and having it perform so well.
Reading this, you might think, "Hey, no fair! I don't have a refractometer!" To which I'd say that you have a nose and mouth and they will provide you with excellent feedback. If, on top of that, you have a good coffee grinder and a bit of patience, you'll be golden. Tinker. Try manipulating your variables one at a time: amount of water, amount of grounds, grind size. Start with the recommendations in the Oxo manual, which will get you going in the right ballpark. Find what you like. Lock it in. It's not that tricky.
The Oxo 8-Cup Coffee Maker is not without imperfections. Most notably, there's no timer. One of my favorite features on my Mr. Coffee is syncing coffee brew time with my alarm clock. Even better is syncing it for early risers' wake-up times when we have guests, which can buy me a few extra Zs. There's perhaps a tiny quality loss in not grinding just before brewing, but it's an easy tradeoff to make on a busy morning. I also wish the water tank was removable, which would make refilling it easier. On a related note, while the carafe pours brewed coffee wonderfully with the lid on, it's a bit sloppy when the lid is off, especially when you're using it to fill the water tank. You'll also need to get used to keeping two filter sizes at home, and (potentially) two different grind sizes if you're making a pot or a cup.
All that is pretty trivial, though, when you consider that it makes very good coffee, and compared to almost every other coffee maker on the market, it brews small amounts exceedingly well. It's also easy to use. If there were any doubts, in my book it puts the nail in the coffin on Keurig and their kin for home use. This coffee maker hits all the marks.