When coffee professionals talk about acidity in a brew, they’re not referring to the beverage’s number on a pH scale. In fact, coffee has relatively low pH, and is less acidic than orange juice, beer and even seltzer water. (People often equate the upset stomach that some coffee can cause with a high level of acid, but a sensitivity to caffeine or even simply bad brewing can cause that discomfort.)
In terms of coffee flavor and character, acidity or brightness are terms used to describe the fruit-like sparkle a coffee might have, sometimes described as its effervescence. It’s a highly prized part of the coffee-tasting experience, but it can be difficult for anyone to detect without training.
Like coffee, apples have varying levels of acidity, ranging from flat to bright and puckery. Train your palate to recognize acidity with this easy exercise.
- 1 Granny Smith apple
- 1 Pink Lady or Honeycrisp apple
- 1 Red Delicious apple
- 1 McIntosh, Empire or Macoun apple
- 1 Fuji apple
Slice each apple into wedges and arrange on separate plates. Then taste each apple variety twice: On the first taste, firmly hold your nose. Without your sense of smell, you’ll be forced to concentrate on the feeling that the apple creates in your mouth. Then, taste the apple again with your nose released, being sure to pay attention to that sparkle again. Notice that with your nose released, its more apparent how sweetness can balance or mask the brightness. Once you’ve tasted every apple, try to identify them from least to most acidic.
Coffees vary in the same way. Some will be distinctively bright, and some will be much sweeter than they are acidic. This depends partially on the variety of coffee bean (Bourbon variety, for instance, tends more toward the sweet side; Kenya’s famous SL-28 variety is tropical and dazzling), but can also be affected by processing and roast level. Coffees labeled “washed process” typically have more acidity, and “natural process” beans have a more tempered, almost cooked-berry-like flavor. Lighter roasts usually display more acidity than dark ones.
If you prefer coffees with high acidity, East Africa might be the origin for you. Central and South American coffee tends to be a bit in the middle range—more like that Fuji than the Granny Smith, for instance. And while they typically lean toward a more savory-sweet mix, Pacific Island and Asian coffees are on the lower end of the spectrum, sometimes barely rating in the acidity rankings.