Though he still likes to think of himself as a barista, Peter Giuiliano, Chief Research Officer at craft coffee’s most important trade group, the Specialty Coffee Association, is a scientist in all but title. The man behind one the most rigorous testing process for home coffee makers speaks of coffee’s past in the way a World War I historian might describe the events of Verdun. He knows where coffee’s been and where it’s going. But his job is to study where coffee’s at: “It’s easy to get caught up in the minutiae of the whole thing,” Giuliano said, “but at the end of the day we’re just trying to show people the machines that make the best coffee.”

Less than 10 years ago, there were only two home coffee makers pinned with the Specialty Coffee Association’s Certified Home Brewer badge, which had already been around since the ’80s. But in the last decade, the demand for cafe quality joe at home has risen, and the program has burgeoned, adding another 11 to its ranks, with more being submitted for certification every year.

Those machines — which include the likes of Technivorm’s Moccamaster ($310), Bonavita’s BV1900TS ($115) and BV1900TD ($133), the Breville Precision Brewer ($300), Behmore’s Brazen Plus ($130) and Connected ($170) brewers, the Bunn 10-Cup ($130), both of OXO’s On series makers ($200 for 9-cup, $290 for 12-cup), the Kitchenaid Pour-Over brewer ($135) and KCM0802 brewer ($160), Wilfa’s very pretty Precision Coffee Maker ($200) and Cuisinart’s PurePrecision ($180) — are, according to Giuliano, the makers that represent the greatest in home coffee brewers. Why?

When I asked Phil McKnight about the certification program, Breville’s Global Business Manager for beverage products, he paused, then chuckled. “Yes, it’s, um, quite rigorous,” he said.

The coffee makers that make the cut are typically slightly pricier than the average maker, but not overly so. Bunn’s simple 10-cup maker ($130) and Behmore’s Brazen Plus ($130) reigns as the most affordable, and the elder statesmen of SCA certified brewers, Technivorm’s Moccamaster ($310), the least frugal option.

The certification program provides a set of standards for brewers to meet. Perhaps the most significant is something the called the Golden Cup, a mythical way to describe yield with a coffee-to-water ratio of 55 grams per liter. Not only must brewers be able to produce this ratio within a 10 percent margin of error, but they need to do it twice — once at full capacity and once at a one-liter capacity. To make matters more difficult, the brewers have to do it with water between 195 and 205 degrees Fahrenheit.

To achieve certification, brewers must also contend with a confluence of technical standards set by the SCA and European Coffee Brewing Center. Machines must be able to brew their full capacities of water in four to eight minutes; they must hold the temperature of the delivered water to Golden Cup standards; they must saturate the grinds with precise uniformity; and they must be able to keep the brewed coffee between 176 and 185 degrees after brewing (for at least 30 minutes). Any misstep, even by just a few degrees Fahrenheit, is a fail.

At one point in our conversation, Giuliano noted that the standards and tests are based on mountains of research into consumer coffee tastes that goes all the way back to the 1950s. “We’re not making this stuff up,” he said. The goal is simply to identify machines that are capable of doing what people want them to do.

“Think about all the things you have to get right in these machines to meet the standards to make the best cup of coffee, then remember you have to make it fit on someone’s countertop and preferably under their cabinets,” said Brian Gross, the engineer behind two SCA-certified brewers from Bonavita.

Gross explains the most difficult part of the brewer certification is how each challenge plays into another: “Only 30 percent of coffee is extractable from the grinds, but you have to make sure you’re only extracting between 18 and 22 percent of it for the perfect cup, and you have to do that with water that is between 195 and 205 degrees. And, of course, you have to make something that works for different sized pots of coffee.”

According to McKnight, brewers that achieve certification are more than just coffee makers. They’re “technical marvels.” Bonavita’s two certified brewers — which were able to nail every obstacle in the certification process, and retail for significantly less than others on the list — feature an extra-wide water showering head and a pre-brew infusion function that de-gases the grinds, making for a cleaner cup of coffee. As is their tradition, Breville took it to the next level with a completely unique water-heating method that allows a full 12-cup pot of coffee to brew in seven minutes, making it the fastest 12-cup on the market (a system that heats water as it flows to the grinds, as opposed to before, is to thank). It took four years to make.

Though there’s much to do about certifications, Giuliano is firm in his belief that coffee, although possessing functionally limitless complexity, has one task that matters. “Ultimately, we’re there to make people’s most delicate time of day just slightly better,” he said.

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