Coffee generally has a pH ranging between 5 to 6, so it’s on the acidic side.

Why did I say “generally?” That’s because different types of coffee drinks tend to have varying pH values. Here is the pH value of some different coffee drinks.

• Espresso pH: from 5.11 to 5.65 based on values measured in an Indonesian study (1).
  
• Drip Coffee pH: from 4.85 to 5.10 based on a Thomas Jefferson University study published in Scientific Reports (2).
  
• Cold Brew Coffee pH: from 4.96 to 5.13 based on a Thomas Jefferson University study published in Scientific Reports (2).
  
• Milky Drinks pH (including lattes and mochas): from 6.26 to 6.36 based on dental data (3).
  
• Coffee with creamer pH: about 6.75 (3)

Note that milk is still slightly acidic, but less acidic than coffee itself. So it has an overall positive effect on the pH of black coffee.

Further, it’s important to remember that the pH also depends on the roast type, water, and other factors. Two drip coffees could have vastly different pH values. Low-acid coffee beans are also popular options and may have a slightly higher pH of 5.5+(4).

Now, let’s take a look at the approximate pH of other liquids and materials and see how they compare with the pH of coffee drinks. The following values were obtained from the US Geological Survey (5) unless otherwise indicated. I’ve bolded some substances of interest.