Coffee Acidity is the bright and dry taste that adds life to a coffee. It is akin to the dry but bright sensation experienced on the back sides of your tongue while drinking red wine. In terms of the pH profile, coffee rates as low-acid, coming in at 4.5 – 6.0, depending on the coffee. (pH 7.0 is neutral).
Acidity in coffee is not related to its pH level, and is actually considered to be a desirable quality. Acidity refers to the flavor profile, similar to the sensations you experience when drinking wine: the tartness, brightness, zing or various regional influences in the bean that hit both your tongue and your palate when you take a sip.
The acidity of a coffee is partly due to the growing region and partly influenced by the way a bean is processed and roasted. Coffee grown at higher altitudes and in volcanic soils tends to be higher in acidity, and is generally more highly prized. Brazilian, Peruvian, Kenyan and Ethiopian beans falls into this category. The coffees that are lower in acidity, such as Sumatra, India, Java and Celebes are grown at lower elevations.
Coffee beans processed by the “wet” method are higher in acidity than those processed by the “dry” method. High acidity would be similar to high carbonation while low acidity would be similar to a “flat” soda.
The roasting process is also very influential. The darker the roast, the lower the level of acid. An Espresso or French roast will be lower in acidity than an American or Viennese roast, for instance.
High acidity: brisk, snappy, bright, dry, sharp, vibrant, crisp, biting, lively
Low acidity: smooth, mellow, sweet, soft
Acidity is just one of the characteristics in a coffee’s flavor. It’s possible to enjoy both low and high acidity coffees. It’s the combination and balance of all the flavor components of coffee that make drinking it a pleasurable experience.
Copyright Coffee Research Institute