There are many words to describe the taste of coffee, but we might not usually associate acidity with our morning brew. After all, a drink with high ‘acidity’ does not necessarily suggest something we’d want to consume. However, the term is often misunderstood.
Coffee acidity is an incredibly important part of the overall taste profile of the drink. The term is not related to acid content or pH value but rather refers to a specific taste attribute.
Coffee Characteristics
When cupping or coffee tasting, there are several key characteristics coffee professionals will assess to determine the quality of a particular coffee and describe its taste more accurately. These include:
- Aroma
- Flavour
- Bitterness
- Sweetness
- Acidity
- Body
- Aftertaste
Acidity might sound like a bad thing, but it is actually one of the key components of coffee’s taste. Acidity is a desirable characteristic that contributes to the overall balance and depth of your coffee, interacting with the other flavours present.
Tasting Coffee Acidity
How we describe coffee acidity depends on how it is integrated into the drink and how it combines with other flavour elements. Descriptors such as bright, lively, zingy, sharp, crisp or tart are often used to express coffee acidity.
On the other hand, if acidity is not balanced with other characteristics it may lead to a sour taste, and not enough acidity can lead to a less complex, dull flavour.
While acidity is considered a good thing, the level that’s ‘best’ will come down to personal preference and the kind of flavours you enjoy. If a coffee has a high acidity, you may pick out citrus and other fruity notes. A mellower acidity level may have more of a chocolate or caramel hint.
Is Coffee Acidic?
Coffee is naturally slightly acidic and sits at around 5 on the pH scale (with 7 being neutral and 1 being most acidic). For context, lots of citrus fruit juices are more acidic and often reside between 2-4 on the scale.
The pH scale is not really a measure of flavour, so when we talk about coffee acidity, the actual pH value is largely irrelevant.
What Type of Acid is in Coffee?
There are various different kinds of acids present in coffee that help build up the flavour and coffee acidity profile. These fall under two categories – organic and chlorogenic.
Chlorogenic compounds are broken down during roasting to produce the following acids.
- Caffeic acid: also found in various fruits and vegetables and has an intense bitter taste.
- Quinic acid: responsible for the bitter and sour flavours that can be found in coffee.
The organic acids are what you’re probably hoping to find in a coffee as they help influence those fruity, vibrant tasting notes.
- Citric acid: found in lemons and oranges, providing a sharp, tart flavour.
- Tartaric acid: can provide a grape-like flavour.
- Malic acid: can provide sweet and sharp fruity notes reminiscent of green apples, pears and plums.
- Acetic acid: adds a vinegary flavour which can be unpleasant if it’s too strong.
What Affects Coffee Acidity?
The levels of these acids and subsequent coffee acidity taste can vary from coffee to coffee for a few reasons.
How the Coffee is Roasted
The chemical reactions that happen when you roast coffee can change the acidity present. For example, a darker roast can soften the acidity, while increasing the richness and body. Lighter roasts tend to have a higher acidity.
You’ll also find that cold brew coffee has less acidity than hot coffee because the cold brew process extracts less of the coffee bean’s acids.
Growing Environment
The environment in which the coffee is grown can also have a significant impact on acidity and flavour. Climate, elevation, coffee variety and eventual processing can all affect acidity.
For instance, if coffee is grown at a higher elevation, you’ll often find it has a higher acidity with more complex flavours. For this reason, Arabic coffee beans are more acidic than Robusta.
You’ll find all sorts of flavour profiles and acidity levels at your local coffee shop franchise, so next time you pop in why not have a chat with the barista about what’s on offer and really savour the intricacies of a humble cup of coffee?!
To find out more about what goes into the best coffees available, check out our guide to speciality coffee.
