Coffee Alphabet: A is for Acidity

Coffee Alphabet: A is for Acidity

Welcome to the coffee alphabet, the quickest way to easily learn everything you need to know about speciality coffee, and the art of enjoying it! Let’s start with ‘A’, which is for ‘Acidity’.

We wanted to share even more speciality coffee knowledge with our customers and coffee lovers. But even if you do really love coffee, you don’t necessarily always want to read through an array of blog articles or descriptions when trying to understand it. That’s why we’ve gone back to our early school days to relive our learning experiences, and deliver a simple glossary of coffee’s most important terms and concepts.

Welcome to Modern Standard’s ‘Coffee Alphabet’!

You may have seen our coffee alphabet posts begin to surface on our Instagram account, if you haven’t visited us on the gram, then check out our page. We’re now bringing those posts to our blog where we can explain them in a little more detail for those who do want to dig a little deeper. We’re kicking off our coffee alphabet learning experience with one of its most vital components, acidity.



Acidity in flavour

Acidity is important, not just in coffee but in all flavours really. It is one of the fundamental building blocks of flavour, even if you’re eating or drinking something that you wouldn’t necessarily describe as ‘acidic’ it’s there. Coffee is an excellent example because we’re probably more likely to think of bitterness when describing its flavour.

But we guarantee that acidity is there and it plays an important role in what happens in your cup and on your tastebuds when you’re enjoying a tasty brew.


To answer that, let’s start by looking at the basics of how we taste.

Wine tasters and seasoned chefs will already know that there is a fundamental difference between aroma and flavour. It’s a popular misconception that we can actually taste strawberries, or chocolate or anything else. These are merely profiles that our brains have developed based on the combination of specific tastes and aromas, and it is largely down to aromas that we can build these profiles with such complexity.

Humans can actually only taste five things;

  1. Sweetness
  2. Sourness
  3. Saltiness
  4. Bitterness
  5. Umami (this refers to savouriness and can be hard to imagine, just think of a packet of beef flavoured crisps and that savouriness is umami)

The balance in which these tastes are present combines with the volatile aromas we smell (first with our nose and in the back of our throat) to create the flavour profile. Acidity plays into all of these things, which explains why we reference it so frequently when describing speciality coffees.

You have probably read a bag label that described the coffee as having ‘sweet acidity’ or ‘citrus acidity’ before, that’s really just us tasting a combination of sweetness and sourness caused by the acids in the coffee (we’ll get to those shortly). Of course, the complex and volatile aromas will influence the ‘flavours’ we associate with this (eg, red berries, jams, lemons, etc).



How can we taste acidity?

Of all of the tastes that we can detect with our tongues, I think that acidity is the easiest to define. Different people have different palettes however, some of us are highly sensitive to bitterness, others to sweetness and so forth. Something as simple as a glass of lemon infused water can taste very different to a room filled with one-hundred people.

So, getting to know your tongue will definitely help you harness your senses and even improve your enjoyment of coffee. Let’s imagine that you’ve bought a bag of Colombian single origin espresso beans and you can’t seem to taste of other than sourness. You may have been drinking the wrong beans in your everyday brew because your palette is more sensitive to sourness than any other taste.

Take another look at the tongue diagram above, the main areas where we taste sourness and sweetness are around the edges, especially down the sides for sourness. These tastes are the ones that tend to make our mouths salivate the most (don’t be bashful now) and this is often the easiest way to identify acidity.

Try taking a sip of fresh orange juice, which can be incredibly sweet and high in acidity, then just be aware of how long your mouth seems to tingle and salivate for afterwards. I’ll bet just thinking about it has fired up those senses already!

As a general rule of thumb, the foundation of coffee flavours are made up of sweetness, sourness and bitterness, which we now know is affected by acidity. It would be unlikely that you can identify any traces of salt or umami. But where does acidity in coffee come from?



Where does acidity in coffee come from?

It’s actually not so hard to imagine where acidity comes from in coffee when we remember that it’s just like any other natural product and the bean comes from the inside of a cherry. Coffee cherries, like all fruits and vegetables, are made up of alkaloids, proteins & amino acids, carbohydrates, and lipids.

Different varietals and even species of coffee plants will be different in their makeup, and you could say each bean has its own ‘genetic profile’. The environment will have an impact on this, along with the climate, the water source and the ground in which the plant has grown. So, before we’ve even hit the roaster we can see that the beans levels of acidity will already be changeable.

Roasting has a massive impact on acidity, bitterness and sweetness. The goal of the roaster is always to bring out the very best tastes and compounds aromas inherent in the beans, while also maintaining a good balance of tastes, to make for an overall pleasant drinking experience.

We won’t go into a whole lesson on how roasting works today, but the important thing to remember here is that it is like any other cooking process. You’re releasing the volatile aromas from within the bean, and caramelising the sugars and acids to release the tastes of sweet, sour and bitterness.

If you try to brew with a raw coffee bean, you’ll struggle to taste much of anything as those aromas and tastes haven’t been released from roasting. On the other hand, if you brew with a coffee bean that has been roasted too much, you’ll only likely taste bitterness, as the sweetness, sourness and volatile aromas will have been all but burned away.


Rounding up...

We’ve learned that coffee beans like all natural products contain acidity, and roasting is important for bringing the best out of it. We’ve also learned how to identify acidity and how it affects our ability to taste sweetness, sourness and bitterness in coffee. Take a look around our online store to read a few descriptions of how acidity can be interpreted in coffee, why not even try a few for yourself?

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