How to Brew Perfect Coffee

4 Things that Determine the Acidity in a Cup of Coffee

how much coffee should I use

Read on to learn about the 4 things that determine the acidity in a cup of coffee!

Have you ever taken a drink of coffee and found yourself on the bitter end of your drink? I have and I can tell you that this makes for a very unpleasant cup of coffee.

That bitterness tends to happen based on the acidity in your coffee. So, what is acidity and why should you be able to taste it in your coffee?

how much coffee should I use

Is the acidity a good or a bad thing? What happens to the acidity when you brew or roast your coffee?

I know we all have a million questions about this, and today, we are going to answer all of them (hopefully) and unmask the curiosity behind the acidity in your coffee.

[Related article: How to Remove the Bitterness from Your Morning Coffee]

What is Acidity and Why Do We Need to Know About it?

Basically, the acidity in your coffee, especially if you are drinking single-origin coffees, are the notes of tangy, sharp, bright, fruity, and sparkling that is used to describe each sip.

But -- this is not always the case and acidity can be a number of different things. It comes in many different forms.

The amount of acidity in your coffee affects the flavour and the aroma through different flavour profiles like the different stone fruits used or even apples for that matter.

Some people even explain acidity as a "mouthfeel", meaning that someone who knows about the acidity in coffee and determines the levels based on the sharpness that coffee leaves in your mouth. No sharpness: no acidity or very low acidity.

However, the exact amount of acidity in your coffee can determine a delicious cup from a bad cup, so let's look at the 4 things that could affect the acidity in your coffee

#1 The Type of Plant Grown

Plant growth and fruit development of each coffee plant predominantly result in the formation of chlorogenic, citric, malic and phosphoric acids.

These acids can all be affected by whether a plant is grown in shade or at a higher altitude. Shade-grown and high altitude coffee plants tend to have higher levels of organic acids, chlorogenic acids, caffeine and sugars.

When you have a slow formation of the fruit under these conditions, this allows for more nutrients to be packed into the fruit, resulting in higher levels of sweetness and organic acids in the cherry.

The type of plant also plays a huge role in the acidity. For example, the two most widely known are Robusta and Arabica.

The Robusta coffee species exhibits much higher levels of chlorogenic acid (around double the quantity) than Arabica.

Because of that Robusta offers a bitter taste, where Arabica offers a milder flavour profile.

[Related Article: The Journey of the Coffee Bean - from plant to cup]

#2 How the Cherries are Processed

There are several different processes to getting cherries ready to send out -- washed, semi-washed, and dry. These all play an important role in the acidity level of your coffee.

Washed coffees are first pulped and then soaked. This process removes a lot of content from the coffee, leaving high levels of acidity.

Washed coffees typically have the highest overall level of acidity in their cup profile.

Naturally processed coffees(which are our favourites) leave all of the fruit intact.

By doing this, it increases the sweet flavour profile in each cup of coffee you dirnk.

Pulped naturals fall somewhere in the middle with a mixture of defined acidity and an increased level of sweetness.

[Related Article: Which Countries Grow the Best South American Coffee]

#3 How the Coffee is Roasted

Roasting coffee is where you really start to see the acidity levels come out in the coffee flavor profile.

Lighter roasts emphasize acidity coffees described as bright or with the taste of citrus fruits usually get these characteristics from acids such as malic acid.

Light roasts and medium roasts have risen in popularity with the third wave of coffee, possibly because they are well suited for brewing single-origin beans with pour-over methods.

[Related Article: What is First Crack in the Coffee Roasting Process?]

#4 Brewing Your Coffee Perfectly

While the type of acidity in coffee is largely determined by the three things I mentioned above, the amount of acidity that happens during the brewing process is all up to you!

You'll notice that as the coffee cools, it the sourness of your coffee will increase. While coffee is cooling, quinide (a tonic water-like phenolic compound) converts to quinic acid which affects the taste in the cup.

water for coffee brewing

Acidity is typical of under-extracted coffee. Under-extraction happens when your grind size is too coarse or your brew time is too short.

The perfect grind size and brewing time depend largely on your brewing method. Just find the right recipe for you and stick to it

Of course if your coffee still has a little bit of a bitter or acidic taste to it, try adding some milk.

The milk helps to balance out the pH level.

[Related article: What is the Best Non-Dairy Milk for Speciality Coffee?]

Finally

While you can't avoid acids in coffee, you can choose coffees that aren't overwhelmingly acidic. You should now have a much more solid foundation to talk about your experience with coffee's acidity.

Now, get to brewing and make a great cup of coffee. I'm off to have a cup myself!

The Kitchn offers more insight to the acid in coffee so be sure and check their article out as well.

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