I did run up against two peculiarities affecting cleanup. When making a small batch of 2 to 4 cups, the Oxo beeps to indicate the cycle is done—then continues to dribble out about a tablespoon more of coffee after you’ve walked away with your mug. Separately, I found the carafe a bit annoying to clean because I couldn’t fit my hand in there like I could with the smaller 8-Cup carafe.
To ramp things up in a hurry, I went to see WIRED friends and star baristas Sam Schroeder and Reyna Callejo at the Seattle lab of Olympia Coffee Roasting Company, and they really liked the preheating tank.
“If you’re heating as you’re brewing, it slows down the brewing,” said Sam, Olympia’s co-owner. “This heats water, then brews, like a commercial brewer, which helps move a larger amount of water through faster. This is where most brewers fail.”
“This is fancy tech,” said Reyna, Olympia’s director of training and innovation. “I’m surprised we haven’t seen more of this.”
For testing, we used Olympia’s Kebeneti Peaberry Micro Lot 9 from Kenya, the drip being served from the Fetco commercial brewer in the café that day. This allowed us to compare what we were making to the café’s completely dialed-in brew.
We pulled out our thermometers, scales, and timers and got to work. Filling the Oxo to the 8-cup line, Reyna ground coffee to the equivalent of a 15 to 17 grind setting on a Baratza Encore, a bit finer than the midpoint. The preheat took less than three minutes, and the brew itself about six, which they liked, comparing it with a brew time for a Chemex. The temperature of the coffee in the carafe was 176 degrees, which Sam referred to as “nice, hot coffee.” Sipping, we found it a bit overextracted, with the tannic, smoky, and bitter notes pushed a bit too far to the fore, something easy to notice when compared to the rounder and juicier coffee from Olympia’s commercial brewer. Reyna made a new batch with a bit more coffee and a larger grind size, which got us most of the way there. Or, as she put it, “no more cardboard aftertaste!” It made clear that we were on the right path, causing Sam to declare that we could tweak our way there.
A full carafe’s worth of coffee gave similar satisfaction, and we watched, impressed, as water flowed more quickly through the grounds than on the medium-size batch, keeping the overall brew times similar. The bed of grounds was also uniformly damp, with no dry patches, thanks in part to the machine’s nice wide showerhead.
“It brewed in seven minutes,” noted Sam, clearly impressed with this machine, especially compared to less exacting home brewers with notably longer brew times. “It’s taking what we know about commercial brewers and applying it to home brewers.”
The total dissolved solids (TDS), often referred to as “the amount of coffee” in your coffee, was a little high, but as Reyna noted, we could fix it by adjusting the amount and fineness of the grounds.
