Ratio Four Series Two: The Drip Coffee Maker That Brings Out the Best in My Coffee

WIRED's lead coffee writer explains why the Ratio Four is his go-to for brewing the perfect morning cup.

Published on Mar. 7, 2026

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For more than a year, the Ratio Four coffee maker has been the source of Matthew Korfhage's daily morning brew. As a self-proclaimed drip coffee devotee, Korfhage has found that the Ratio Four allows him to enjoy the pure, unadulterated flavor of his favorite beans, delivering a cup that rivals the quality he can get from his local specialty coffee shop.

Why it matters

Korfhage's story highlights how the latest generation of home coffee machines has elevated the humble drip brew, making it a viable option for coffee connoisseurs who previously may have turned up their nose at anything other than meticulously crafted espresso or pour-over. The Ratio Four represents a new era where technology has caught up to allow even casual home brewers to enjoy the full aromatic potential of their beans.

The details

The Ratio Four, now in its second generation, has become Korfhage's go-to coffee maker for its ability to consistently produce a clean, flavorful cup of drip coffee. Korfhage was first introduced to the potential of light-roast, immersion-brewed coffee at specialty cafes in Portland, but struggled to replicate that level of quality at home until discovering the Ratio Four. Its precise temperature control and even saturation of the grounds allows Korfhage to enjoy the fruity, aromatic notes of his favorite beans without the bitterness or muddiness that can plague inferior drip machines.

  • Korfhage has been using the Ratio Four for more than a year.
  • The Ratio Four Series Two is the latest generation of the coffee maker.

The players

Matthew Korfhage

WIRED's lead coffee writer and a self-proclaimed drip coffee devotee.

Ratio Four

A high-end home coffee maker that Korfhage credits with allowing him to brew the perfect cup of drip coffee.

Wille Yli-Luoma

The Norwegian owner-roaster of Heart Coffee Roasters in Portland, who introduced Korfhage to the potential of light-roast, immersion-brewed coffee.

Heart Coffee Roasters

A specialty coffee shop in Portland that helped Korfhage discover the aromatic purity of light-roast coffee.

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What they’re saying

“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.”

— Matthew Korfhage, WIRED's lead coffee writer (WIRED)

The takeaway

The Ratio Four coffee maker represents a new era where technology has elevated the humble drip brew, allowing even casual home brewers to enjoy the full aromatic potential of their favorite beans. Korfhage's story shows how a high-quality drip machine can rival the quality of specialty coffee shop brews, making it a viable option for coffee connoisseurs who previously may have turned up their nose at anything other than meticulously crafted espresso or pour-over.