Acidity in coffee is much more than the pH level. It is often said that coffee is a high acid food but with a pH level of 5, coffee is as acidic as bananas and technically less acidic than tomatoes.
The meaning of acidity in coffee I want to dive into is acidity as a flavor and aromatic compound.
The term acidity in coffee typically has to do with its vibrance and liveliness, this perceived acidity is one of the main categories that the coffee industry uses to score coffee quality. Acids can represent up to 6% of the total mass of a roasted coffee bean and not only impart taste and flavor themselves but are recognized as flavor precursors.
We've touched previously on the transformative effects fermentation has on the biology of the coffee bean, roasting further alters its composition and with it affects these acids, their concentration, and distribution. Though we are familiar with acidity as a pronounced tartness or citrus flavors thanks to Citric and Phosphoric acids, Malic acids actually taste of apple or stone fruit. With some acids such as Chlorogenic and Organic acids being responsible for flavor while also dictating the body of the brewed coffee.
Coffee tends to be “brighter” the lighter that it is roasted and more bitter the darker it is.
All acids react differently to the roasting process decrease in quantity as roasting takes place, while others such as the Aliphatic acids increase in potency. Acetic Acid is one of the latter,
it increases proportionally to the roast and though it tastes of ripe fruit in lower concentrations, it can turn into vinegar when present in large amounts.
Acidity alters our taste perception, it augments sweet, salt, and bitter flavors so it’s not necessarily a bad thing to taste since it heightens your sensory experience. After all, the goal of specialty coffee is to provide a remarkable and exciting experience through a differentiated coffee that depicts its origin and its producer.
So don’t run away from acidity (unless it causes you gastrointestinal issues), instead, take note of what you like and what you don’t and find coffees that fit that description. The recent years in coffee have shown us that coffee can taste a variety of ways and as processing techniques are mastered and knowledge continues to be shared within the coffee community, we as consumers are the privileged ones.
Acidity in coffee chart thanks to: <a href="https://www.freepik.com/vectors/ph">Ph vector created by brgfx - www.freepik.com</a>