A Delicate Dance: Sweet, Sour, and Bitter

Acidity plays an integral role in a coffee's taste, mouthfeel, and aroma. With an average pH ranging from 4.8 to 5.1, coffee is naturally acidic.

Often described as "brightness" or "vibrance," acidity is sometimes perceived as sourness, but it's much more than that. Pleasing acidity complements the sweetness of coffee and can be described as bright, crisp, vibrant, or sparkling. It comes from one of the many organic acids in coffee, and we often relate it to foods that mimic the taste we're perceiving. Flavor notes such as wine, green apple, lemon, stone fruit, and vinegar all denote different types of acidity.

Acidity can both complement the sweetness of coffee and affect your perception of bitterness.

Imagine if Coca-Cola or iced tea had no acidity or sourness; it would taste rather flat and excessively sweet. The same can be said for coffee!

It's important not to confuse acidity with the burning, nauseating, and unpleasant feeling in your stomach after drinking a poorly brewed or burnt coffee, which often causes heartburn. This is the result of quinic acid in coffee being exposed to excessive amounts of heat and water. Think of diner coffee sitting on a hot plate or a Moka pot left on the stove for too long.

Citric acidity 

The most common type and is most prominent in fresh coffee. It often reminds tasters of lemons, limes, oranges, and pomelo.

Acetic acidity 

Found in natural or anaerobically processed coffees. It has a positive wine-like, fermented, or even vinegar note and contributes to the syrupiness or mouthfeel of a coffee. However, in excess, acetic acidity is considered a defect and is usually caused by an error in the processing of that coffee.

Malic acidity 

Rare and delicious, this type of acidity has a tart, green apple-like, or stone fruit taste in coffees. Central and South American coffees, and more specifically Colombians, often have malic acidity.

Phosphoric Acid

While phosphoric acidity itself has no real taste, it contributes to our perception of the overall acidity in coffee and can create a sparkling or dancing sensation on the tongue reminiscent of drinking tonic or cola.

Quinic Acid

Quinic Acidulation adds a negative quality to your cup and is caused by the breakdown of chlorogenic acid during the roasting process. Manifesting as bitterness and astringency, Quinic acidulation is often what contributes to heartburn in coffee, often caused by improper roasting techniques, prolonged brewing and heated storage of coffee.

Ready to taste the difference? Compare our Peru San Ignacio, known for its bright, fruity malic acidity, with our Weekend Blend, which showcases a more pronounced wine-like acetic acidity. Or, for a classic clean citrusy washed coffee, try our latest coffee from Colombia!