A couple of weeks ago a friend of mine asked if we sold coffee that was "less acidic" and easier on the stomach. We get a lot of customers who ask the same question, particularly when it comes to the acid levels of other brands or roasters. The short answer is no. That's really a myth but there is a solution, well, kind of.
All specialty-grade Arabica coffees have the same pH level. Roast profiles, different coffee varietals, or even different brew methods do not have a substantial effect on cutting down the acidity found in coffee.
Let's start with the basics. Remember the science experiments you did in the 7th grade? Those little white strips were called pH Test Strips and were used to measure pH levels.
To refresh your memory water is neutral at a pH of 7, lemons are pretty acidic at a pH of 2, and drain cleaner is very basic at a pH of 14.
A typical black coffee measures at a 5 which is similar to the pH of a banana, yup a banana. As you can see from the scale below, coffee is technically acidic, but not by much. You will find similar acidic levels in soda, orange juice, and even some beers.
Time To Experiment
But there are customers that swear a light roast is easier on their stomach, or a particular region sits better.
So I decided to run an experiment on my own and test out a variety of different coffees, roast profiles and brew methods.
I purchased a digital pH meter that has an accuracy down to the hundredth of a pH. I also setup a "control" with a pH of 6.86 for calibration. Distilled water was used in between each test to make sure there wasn't any contamination. I ended up testing nine different types coffee.
What clearly stands out from the graph below is the minor difference in pH levels between roast profiles, brew methods, and coffee origins. The pH difference from our Costa Rica Light to Cold Brew is only 0.52. Even our Kenya coffee, which is known for its citric flavors had a very similar pH level.
If you ever had a cup of coffee that didn't upset your stomach think about what else you ate that day, or if you added milk. It most probably isn't related to the coffee itself.
So Is There A Solution?
You do have a couple of options to "tamper" down the acid levels, but to be honest, it's not by much. I encourage you to test the two options below and see if they're able to help you out.
Dark Roasts - a study published in 2010 found that dark roast coffee is easier on the stomach than light roasts because it produces an ingredient that prevents hydrochloric acid from building up in the stomach.
Cold Brew - brewing coffee using the cold brew method has been shown to increase the pH level of coffee. The theory is that the cold water extracts less of the oils found in hot water extraction which results in a lower acidic coffee. In my experiment I was able to "bump up" the pH level by a very small amount. How To Make Cold Brew.
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