Coffee Acidity

Let’s get straight to the point, coffee is an acidic beverage. Acidity is also one of the most prized components of a great coffee. That said if a coffee is too acidic it can taste sour and without acidity it can taste flat. Finding the right balance is part of the ‘art’ of coffee.

Most coffee varieties are acidic by nature, with an average pH value of 4.85 to 5.10 (Source).

Coffee is loaded with a variety of compounds that during the brewing process are released. This includes nine major acids that contribute to its unique flavor.

In case you want to file the information away for your next trivia night, here are the nine major acids in coffee, listed from highest concentration to lowest: chlorogenic, quinic, citric, acetic, lactic, malic, phosphoric, linoleic, and palmitic (Source).

Organic acids include citric, malic, quinic, acetic, succinic, and tartaric acids. These are the “good,” fruity acids that you want to taste in the cup. (Source)

Each of these adds their own particular notes to the coffee:

  • Malic acid is the same kind of acid that you get in green apples, so think brewed coffee with the juiciness and smooth sharpness of green apples.
  • Citric acid not surprisingly is more citrusy. Think lemons, oranges, and nectarines.
  • Tartaric acid is more grape-like.
  • Acetic acid, on the other hand, is more vinegary and less pleasant.

Then you have chlorogenic acids, which get broken down (normally during the roasting process) into quinic and caffeic acids. The thing is, quinic acids are not a good taste. “These compounds are responsible for bitterness, astringency and sourness in the beverage.”

Watch this video if you want to geek out some more on the chemistry of coffee.

Contributors to Variations in Acidity in Coffee

understanding coffee acidity and how to make a low acid coffee

A number of factors contribute the acidity levels in coffee these can include:

  • Type of bean – origin, variety, species
  • Elevation it’s grown at, climate
  • How the beans are processed (dried)

Then there are the things you have more control over.

  • Roasting
  • Brewing
  • Size of the Grind

Roasting

The length and temperature at which coffee is roasted make a big impact on coffee acidity.

Lighter roasts (usually done at a lower temperature and shorter duration) are higher in chlorogenic acid levels. Darker roasts tend to be lower.

Brewing

Brewing methods also have an impact on acidity.

Brewing time also appears to affect overall acidity, with a shorter brewing duration resulting in a more acidic beverage and a moderate duration resulting in a less acidic one (Source)

Cold brewed coffee is significantly less acidic than hot brews (lower water temperature and longer duration of brew time).

Coffee Ground Size

The size of the coffee grounds can also affect acidity. The smaller the ground, the greater the surface area exposed relative to volume, which can lead to more acid being extracted in the brewing process (Source).

Therefore, using a finer grind may result in a more acidic cup of coffee. Espresso grind and brewing will be more acidic than say a French Press grind and brew.

What Does it all Mean?

Many people say they don’t enjoy the ‘bite’ that coffee has. Often that strong flavor is due to the acidity levels of the coffee. Others experience reflux after drinking coffee and are looking for ways to reduce that unpleasant outcome.

If you prefer a more mellow blend then it may be worth trying a different coffee roast or style.

Ways to reduce acidity

Here are a few ways to reduce it:

  • Choose dark over light roasts. (It’s not uncommon for people to think that lighter roasts are also lighter in flavor and acid which isn’t the case).
  • Drink cold brew instead of hot.
  • Increase brew time, such as by using a French press rather than espresso shots.
  • Opt for a coarser grind.
  • Brew at a lower temperature.

Coffee Acidity Reduction Hacks to Help you Brew a Low Acid Coffee

  • The most common ‘hack’ for reducing the acidic taste in coffee is to add milk or cream
  • Choose a low acid coffee
  • Brew a coffee grown at a lower elevation
  • Brew darker roasts
  • Arabica beans are less acidic
  • Drink cold brew
  • Brew your coffee with eggshells (eggshells are alkaline, which means they help neutralize the natural acidity in coffee, balancing things out and even removing any bitter, over-extracted flavors in the process.)
  • Add a pinch of salt to your beans before brewing.

“I’ve taken to adding a quarter teaspoon of kosher salt to every 6 tablespoons of grounds. That isn’t really enough to taste, but it’ll do the trick … research has proven that salt is actually better at neutralizing bitterness than sugar.” Alton Brown (source)

  • Add a dash of baking soda – like eggshells baking soda is alkaline (1/4 teaspoon to a pot).
  • Try different coffee growing regions – Kenya, for example, often grows fruitier and more acidic coffee beans. Coffees from Brazil and Sumatra, on the other hand, tend to have low acidity.

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