Why the Ratio Four Series Two Is What I Use to Test New Coffees

Coffee is the original office biohack and the nation’s most popular productivity tool. As we lose sleep to the changeover to daylight saving time, the caffeine-addicted WIRED Reviews team is writing about our favorite coffee brewing routines and devices that’ll keep us alert and maybe even happy in the morning. Today, reviewer Matthew Korfhage expounds on his lasting love for drip coffee—and why the Ratio Four never leaves his counter. In the days after, we’ll add other Java.Base stories about other WIRED writers’ favorite brewing methods.

As with any vice worth having, a morning coffee routine can take on the character of religion. And like a lot of religion, it’s often born as much accident as moral conviction. My denomination is good, old-fashioned drip coffee. That’s what I drink first thing, before I even think about crafting a shot of espresso.

I’m WIRED’s lead coffee writer and I’ve developed a deep fondness for coffee’s many variations, from espresso to Aeropress to cold brew. But “coffee” to me, in my deepest soul, still means a steaming mug of unadulterated drip. Luckily, that’s also the coffee arena that has been transformed the most by technology in recent years. The drip coffee from the Ratio Four coffee maker (now quietly on its second generation) feels to me like coffee’s purest form, the liquid distillation of what my coffee beans smell like fresh off the grinder.

My love of filter coffee began as a teenager traveling and studying in India—perhaps my first glimpse of adult freedom. This is where I drank the first full cup of coffee I remember finishing. In Jaipur, filter coffee was an intense, jet-black gravity brew typically mixed with milk and sugar. I decided that if I was going to drink coffee, I would take it straight and learn to like it on its own terms. A newfound friend, tipping jaggery into his own brew, laughed at my insistence I didn’t want sweetened milk. I then downed a cup so thick and strong and caffeinated it made my hairs stand at perpendicular. If I’d made a mistake, I refused to admit it.

I carried this preference back to Oregon, drinking unadulteratedly black, terrible drip coffee at all-night diners and foul office breakrooms. Black coffee had become a morality clause, though it was hardly a matter of taste.

It wasn’t until years later that I discovered that drip coffee could actually be an indulgence every bit as refined as pinkies-up espresso.

Upping the Drip

In part, this was a problem of technology. Aside from a classic Moccamaster, it’s only very recently that home drip coffee makers have been able to produce a truly excellent cup. For years, I didn’t keep one at my home.

What woke me up to drip’s possibilities was a new wave of cafes in Portland, first third-wave coffee pioneer Stumptown Coffee and then especially Heart Coffee Roasters in Portland. Heart’s Norwegian owner-roaster, Wille Yli-Luoma, expounded to me at length about the aromatic purity of light-roast immersion coffee—the fruity aromatics of a first-crack Ethiopian that could smack of peach or nectarine or blueberry. Scandinavians had long prized this, he told me, and had evolved light-roast coffee into pure craft. America was finally catching up.

Still, I could never quite get that same flavor or clarity on a home brewer. Not until recently. To get the best version, I still had to walk up the street to Heart and get my coffee from the guy who roasted it. Or I had to spend way too long drizzling water over coffee in a conical filter. I rarely wanted to do this while still bleary from sleep, already late for work.