Acidity is an essential component in arabica coffees. One type has more acidity than the other, and it depends mainly on the variety, a mineral-rich soil and the altitude. To understand the acidity in coffee we advise you to keep reading this blog.
Acidity vs. sourness
Many people think of sourness when they hear the word acidity. Acidity is not a property you immediately associate with delicious fresh coffee. Acidity makes us think more of past experiences when our grandmother’s coffee stood for hours warming on a hotplate or in a Thermos jug. Sourness is an extreme form of acidity and indicates a lack quality in the coffee. So let’s swap the word acidity for ‘freshness’, ‘fruitiness’, ‘liveliness’, ‘sparkle’, etc. After all, that is what we are looking for when we talk about acidity as a positive taste element.So let’s say we are looking for the right proportion of freshness in arabica coffee. Acidity is in fact a broad term that can be used in several contexts, and that is exactly why it can lead to confusion. An insight into the types of acidity helps to clarify the line where positive acidity passes over into its negative aspect.
The most observable types of acidity
Citric
This mainly occurs with high-growing arabica coffees. Think of fruity notes such as orange, lemon, grapefruit, etc. This type of acidity is at its maximum with a light-roasted coffee and it breaks down slowly as the beans are darker-roasted. A perfect roast ensures balanced citrus acidity. To understand exactly what balanced acidity means, consider a lemon: taste an unripe lemon and compare it with a ripe one. That is exactly the difference between positive, balanced acidity and sour negative acidity.Malic
This term mainly indicates the acidity that is associated with that of an apple or a pear, and has a sweeter and riper freshness, which is nicely crisp.Acetic
This is better known as vinegary. It is the type of acidity that is present in both green, unroasted coffee and roasted coffee, but only to a limited extent is it seen as positive.
Quinic
In contrast to the previous types of acidity, quinic acidity develops primarily if the beans are darker-roasted. A very dark roast brings this out to the maximum. So quinic acidity is not one that baristas are looking for, because it causes bitterness and sourness in the coffee. You also experience this kind of acidity in coffee that stands for hours on a hotplate or in a thermos jug.Tartaric
This type of acidity is found in grapes, for example. It can give the coffee wine-like tones. A limited degree of this is positive, but if the concentration is too high, it can give a negative, sourish experience.
The type of processing method also influences acidity
Coffee processed with the dry method has less perceptible freshness than washed coffee. This is mainly due to the higher level of body or mouthfeel you get with a natural coffee. The body masks and suppresses acidity. So you will notice the acidity less with fuller-bodied coffee. Balance is the difficulty we face with acidity.
As soon there is excessive acidity in the coffee and it becomes too sour, it loses its balance. This can be caused by a variety of factors:
1. Method of picking
In the first place, the method of picking has an effect, check out the following blog if you want to know more about the different types of picking methods: 'from picking to processing, uncover the secrets of the coffee bean transformation'.
2. Way of roasting
Secondly, the way of roasting can affect it too. Have a look at our blog: if you want to know more about the way of roasting and it's influence on flavour.
And last but not least, a barista can brew it in the wrong way.
Bitterness
On the other hand, bitterness is actually another important component of coffee’s flavour. A minimal level of bitterness is always present and is a positive trait, because it balances the acidity and ensures that it comes through less sharply. As soon as the bitterness level is too strong, it starts to dominate the other flavours, and is perceived as a negative experience. But don’t confuse bitterness with sourness. As we said before, a certain degree of bitterness is normal and it is a positive trait. Yet sourness is never positive and must be avoided. Coffee drinkers sometimes confuse those two characteristics.
If you want to know more about bitterness, make sure to read our blog: 'How does excessive bitterness in coffee occur?'.
TIP
When you started experiencing coffee with the right acidity, you become more open to flavours and you forgot what coffee used to mean to you. Consider overripe fruit here.