The breakdown: acidity in coffee

Acidity in coffee is marvelous, wonderful, and often misunderstood. Today, we’re breaking down what acidity in coffee means, how to identify it in a coffee description, and where to find high and / or low acidity coffees based on their growing region.

Most easily identified by its pure close or lack of aftertaste, acidity in coffee is very gentle and closely linked to the sensation it creates in your mouth. When sipping a coffee with high acidity, you should experience a smooth, dry, sharp, pleasantly tart, tingling sensation at the tip of your tongue, similar to what you may experience after eating an orange or sipping a lemon-flavored drink. This strong, clean, almost tingling sensation is a hallmark of high acidity coffee. While you don’t necessarily taste lemon or orange in your coffee, your mouth and senses react as if you had. As acidity levels in coffee drops, the tingling sensation gives way to a juicier, wetter feeling in the mouth with low acidity coffees providing a long, almost textured close or aftertaste.

Many factors combine to create a cup’s final acidity level including bean species, varietal, growing region, and roast. Understanding how these factors develop and impact acidity will help you pinpoint coffees that fall into your coffee acidity level profile. First up, bean species and variety. Bean species and variety provide beans with their acid potential, or what I like to refer to as their bean DNA. During formation, that potential will either emerge or be muted by the coffee plant’s growing region, elevation, topography, and terroir. Generally, bourbon beans have higher acidity than typica beans, and plants grown in acid-rich soil have more pronounced acidity than plants grown in sandy or mineral-rich soils. Once harvested, processing method and roast either preserve or reduce the beans’ acidity with dry-processed beans displaying higher acidity levels than wet-processed and semi-washed beans as acidity is diluted / washed off during washing. The final determinant in a coffee’s acidity is its roast. As with water exposure, acidity burns off the bean when exposed to high heat resulting in light roasted beans being more acidic than medium roasted beans, and medium roasted beans being more acidic than dark roasted beans. Now that we’ve covered acidity development, let’s explore how this information is presented in a coffee’s description.

Key terms associated with acidity

While some roasters proudly proclaim the beauty of a high acid coffee, most shy away from the word knowing it often conjures up unpleasant sensations of heartburn and mouth-puckering tartness. Instead, they use words that describe how the coffee feels in your mouth, with the most common descriptions for high and low acidity coffees listed below.

High acidity coffees are often described as clean, bright, lively, light, crisp, and / or vibrant with light or moderate mouthfeel.

Low acidity coffees are often described as smooth, silky, juicy, creamy, dense, and / or mild with moderate to heavy mouthfeel.

Key flavors associated with acidity

In addition to tactile sensations, certain coffee flavor notes are closely connected to acidity.

High acidity coffees often present prominent notes of citrus, tart fruit, tart berry, and grape (often referred to as winey / wine-like).

Medium acidity coffees often present prominent notes of soft fruit (e.g., apple and pear), gentle berry (e.g., strawberry or blueberry), florals, soft spice, gentle nut, and mild chocolate.

Low acidity coffees often present prominent notes of nut, spice, earth, and rich chocolate.

Regional breakdown of acidity from most acidic to least acidic

While it is too broad to say all coffees from a given region are acidic or non-acidic, each region in the coffee belt demonstrates strong acidic tendencies. Generally,

African coffees are highly acidic. Africa is dominated by bourbon plants grown in highly acidic soil. These beans are most often dry processed and dominated by notes of citrus, ripe berry wine, and floral. African beans are generally roasted to either a light or medium shade to preserve the beans’ beautiful light, bright, delicate upper notes. In terms of mouthfeel, African coffees are usually very clean and light on the tongue.

Central American coffees are moderately acidic. Dominated by bourbon and typica beans grown in mineral-rich volcanic soil, Central American coffees are most often wet processed and dominated by notes of fruit, honey, medium-to-dark chocolate, and mild nut. Central American beans are generally roasted to a medium or full-city shade and have good mouthfeel.

South American coffees are moderately / moderately-low acidic. Dominated by typica beans grown at soaring elevations in nutrient-rich soil, South American beans are most often wet-processed and dominated by notes of floral, soft citrus, mild nut. South American coffees are generally smooth with good to heavy mouthfeel.

Asian coffees are low acidity coffees. Asia coffee farmers grow numerous plant varieties and species in varying conditions among cocoa plants and exotic spices. Asian coffees are generally semi-washed and transported in open containers, allowing the beans to absorb flavor notes from the land traversed during their journey to the processing center. Dominated by notes of dark chocolate and spice, Asian coffees tend to be full-city to dark roasted, and are known for their rich, creamy, heavy mouthfeel.

To learn more about acidity in coffee, please check out our Coffee 102: Exploring Acidity kit or listen to episode 17 of our podcast, Coffee With the Queen (available February 25th).