Ask the Barista: What is Acidity in Coffee?

Ask The Barista answers all of your questions about roasts, grinds, and everything in between. Got a question brewing? Email rachael@beanbox.co to have your question answered by the Barista in upcoming blog posts.

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Q: My stomach always reacts to the acidity in coffee. How can I avoid this?

A: In my experience as a barista, customers who are new to drinking coffee tend to be a bit terrified of any coffee that is described as acidic. And who wouldn’t be? The word “acid” conjures up any number of terrifying images: heartburn, stomachaches, and the sharp taste of vinegar or lemon juice. In the world of coffee, we’re constantly talking about “acidity”, but it’s not quite what you think….

Coffee, like most things we like to drink, is naturally acidic. That’s just a fact, but one that needs to be taken in context. Other common drinks, including beer, soda, fruit juice and wine all have much higher acidity levels than the typical cup of joe.

Defining “Acidity” in the Coffee World

When people talk about “acidity” in coffee, they’re not talking about a higher PH level (in chemistry, a measure of the actual level of acidity). They’re talking about specific flavor compounds. For example, the presence of citric, malic, or tartaric acids in the bean is associated with flavors like citrus, apple, and wine. These flavors more commonly stand out in single-origin, light-roasted coffees, and help make drinking coffee such a pleasant experience. Stronger flavor profiles are also commonly referred to as “brightness”.

We conducted a little pseudo-scientific test to show the acidity level of coffee compared to other popular beverages such as beer, soda, fruit juice, and wine. We discovered coffee has a much lower level of acidity than all of these drinks. In fact, soda, apple juice, orange juice, and wine were more acidic than coffee (pictured below). It’s also important to note light roasts generally have a slightly higher PH level than dark roasts, but even that minor difference varies by bean origin. From a pH standpoint, you are consuming a pretty minor amount of acid in your coffee.

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 Experimenting with pH levels at the Bean Box offices. From least acidic to most acidic: water, coffees, soda, apple juice, orange juice, wine. 

It’s Not the Acid That Affects Your Stomach  

In our experience, stomach woes have little to do with the acid levels of coffee. So if you believe it’s the acid in coffee that causes your tummy woes, here’s the test: unless you’re equally upset by juice, beer, wine, or soda, then it’s not the acid that’s the problem. Instead, the likely culprits include:

  • Bean remnants: The level of particulate matter (leftover bean solids) in your coffee beans on how much material your body will need to break down and digest. To minimize this, use a filtered brew method, with a paper filter (far better than wire mesh filters). You should also avoid using a French Press if you have a sensitive stomach. Dark roasts are often harder on the stomach, as more bean material will make it into the final brew.
  • Caffeine: Per above, the more bean material in the brew, the more caffeine will continue to be extracted in the stomach. Caffeine generally prompts the body to produce more gastric juice. Again, brew method can make a big difference: Americanos and espressos carry less caffeine than drip.
  • Milk: Adding milk and its proteins to coffee will absolutely soothe the overall coffee drinking experience, but only for the palate. In the stomach, dairy proteins also stimulate the production of gastric juices. In the presence of other acids, this can for many people be a recipe for woe.

So next time you hear talk about the “acidity” of coffee, remember that it’s just another way to describe the bright flavors present in the bean. And when it comes to preventing stomach problems, focus instead on how you’re brewing, as coffee is, relative to most other drinks, a pretty safe vice.

Cheers to Better Brewing,

The Barista

Have a coffee question? Email rachael@beanbox.co and the Barista will answer it in upcoming blog posts!

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