What is acidity in coffee?

Have you ever heard someone talk about the ‘acidity’ of coffee and wonder what they mean? After all, acid is something that doesn’t always have the most positive of associations- but fear not! When it comes to coffee, it’s all about the flavour. Coffee enthusiasts have long understood its importance in producing a flavoursome cup, but it can be a bit confusing if you’re not sure. If you ask some, they’d tell you that acidity produces a sharp, tangy note and others would swear that acidity is vital for producing complex bright, fruity notes.

Confused and fancy learning more? Here comes the (sort of) science bit!

Acidity affects the ‘flavour notes’ of the bean; acids can determine how bright, crisp, fresh and fruity a particular coffee will be. The three main acids that influence the flavour of a bean are tartaric, malic and citric acids and it’s interesting to note that these are also present in wine too. Together they can combine to create a depth of flavour and can be found in different concentrations, depending on a few different factors:

Soil and elevation: it’s generally considered that the higher the coffee is grown, the more acidity it will have. An example of this would be the Columbian coffee, which tend to be grown at higher altitudes. Volcanic soil, such as that found in parts of Kenya, can also produce coffee with a higher acidity.

Coffee processing: coffees that are produced via washing tend to have higher acidity because less of the fruit pulp is left on the bean. Those which are produced via natural, sun-dried or honey processes tend to be lower in acidity and can have a sweeter taste. (FYI: we’ve created a detailed blog postabout the ins and outs of coffee processing if you’d like to learn more.)

Roasting: roasting is another crucial factor in acidity levels as prolonged exposure to the heat can break down some of the acids. Darker roasts, which have had longer time exposed to heat, will have lower levels of brighter, fruity acidity.

So how do you choose a coffee that you’ll enjoy? It’s all about finding the right level of acidity for you- after all, it’s important to have some acidity in your coffee, otherwise it’ll be a flat and dull cup. If you like a bright flavour with fruity notes, you might like to try a light/ medium roasted Kenyan coffee. If you prefer a smooth, big bodied cup then try out a medium/ medium dark roasted Brazil coffee. It’s all about experimentation… have fun!