Acidity in coffee comes from compounds like chlorogenic acid, quinic acid, and citric acid. Caffeine itself is not acidic—it’s a bitter alkaloid—but it can stimulate stomach acid production. The real story is about the beans and how they’re decaffeinated.
Here’s the twist: decaf isn’t automatically less acidic. In fact, some decaf processes can actually increase acidity. The Swiss Water Process, for example, uses water and osmosis, which can strip away some acids but also leave others intact. Meanwhile, solvent-based methods like ethyl acetate (from fruit) are gentler on pH.
A 2018 study in the Journal of Food Science found that decaf and regular coffees have overlapping pH ranges—typically between 4.85 and 5.10. Translation: the difference is often negligible. It’s like comparing two sparkling waters—one just has a little less fizz.
