Some people (ahem, Matt Buchanan) claim that the coffee maker is the worst of all possible brewing methods. Maybe so—but it's still a machine that bazillions of people use daily.
They make life too easy not to. Mine fixes my coffee while I'm in the shower! You can tell a lazy person 1,000 times that making coffee with a Chemex or a siphon will produce a superior cup, but efficient caffeine administration will trump delicious every time. Counter-top brewers also cheap, which makes it easy to justify purchasing a morning fuel-producing robot, even if it's a mediocre robot.
Consider what our ancestors went through for what's now done while you sleep. The earliest methods of brewing involved boiling water and coffee together, which meant you had to filter out the sediment—and we know now that boiling makes coffee yucky (more on that below). In the early 18th century in France, coffee was brewed inside a linen bag dipped in hot water, much like we treat tea today. Percolators started bubbling up in the 19th century, and until fairly recently, they're what got us going in the morning, mainly because they eliminated straining. But by today's standards, percolator coffee is disgusting. Enter Mr. Coffee. Although it seems this brand has been on our counters forever, the company didn't introduce their first machine until 1972. When they came to market with the first automatic drip coffee maker, plug-in and stove-top percolators became a thing of the past.
Easy, convenient, cheap: that's about the end of the list of good things about the machine on your counter. Peter Giuliano, owner of Counter Culture Coffee and past president of the Specialty Coffee Association of America (yes, that's a real thing), concurs.
And then he kindly walks me through a long list of the unsavory things the auto-brewer inflicts upon our beans and by extension our palates.
To make the best cup of joe, water needs to be between 195 and 205 degrees Fahrenheit. Any hotter, and the water extracts bitter, astringent compounds. The number one offender is the percolator, ubiquitous in the ‘50s. By cycling boiling water over the grounds repeatedly, it changes their chemical composition for the worse. Thankfully percolators have been largely retired. But water cooler than 195-degrees isn't great either. Below that mark and you don't get enough flavor from the beans, leaving you with what Giuliano calls "weak, cardboard-y, sawdust-y coffee." Mmm.
Underachieving temperatures are usually the culprit when counter top makers yield bad coffee—we've traded bitter for bland. Machines like the Technivorm consistently hit the temp target, but such marksmanship is rare. For a machine that precise, you're looking at spending several hundred dollars.
In Mr. Coffee and similar models, an aluminum tube is attached to a heating element. The water is warmed in the tube en route to the grounds. "It's an imprecise way to heat water, but people are into the idea that their coffee maker costs 60 bucks." The lukewarm result? Essence of cardboard.
The water reaches piping temperatures eventually, but it happens too late—after it passes through the grounds. A hotplate keeps the pot steamy, but post-brew is not the appropriate time to bump up the temperature. "It can cook the coffee, which makes weird flavors," Giuliano explains. He points to a compound in coffee called chlorogenic acid. Too much heat and it breaks down into quinic acid—the same stuff that makes tonic water bitter and sour. If you must use a counter-top maker, Giuliano prefers those that deposit into a thermos.
Temperature is just one thing way a counter-top maker can make perfectly good grounds unsavory. The way the water passes through them can also engender sour tastes. When water is pulled up from the tank and sprinkled over the beans, the stream is often dropped right in the center of the filter, whether it's cone-shaped or flat-bottomed. "This creates a single bullet hole, which over extracts the middle and under extracts the outer portion of the coffee," says Giuliano.
Here's why that's a problem: About 35 percent of a coffee bean is soluble in water, but only 18-20 percent of that tastes good. If you're getting more than that 20 percent by over extracting the bean, you wind up with a mouthful of bitterness and cotton, thanks to the tannins that appear. Your filter's shape and the water delivery work together to cause the problem. Sprinkle the water evenly though, and you're more likely to hit that perfectly saturation spot—one important part of what coffee experts call "the golden cup."
Also beware of using too much water for the amount coffee you're putting in the machine. Aim for about two tablespoons per cup of water. (Note: what most coffee machine manufacturers call "cups" are actually an ounce and a half shy of the baking measurement. It makes no sense, but that's a rant for another column. Just make sure you RTFM and use the pot's own measuring system.)
So yeah, the list of problems coffee machine manufactures need to solve to get a better cup is long. Until they find a better way, Giuliano suggests the French press. Or, if after reading this you've seen the light and plan to retire your coffee maker, you could try one of Mr. Buchanan's fancy-schmancy methods.
I, for one, am going to try to forget I ever learned better.