Some people aren't able to drink coffee because it bothers their stomach, but is it really the acid? In terms of the pH profile, coffee rates as low-acid, coming in at 4.5 – 6.0, depending on the coffee (pH of 7.0 is neutral). Most regular sodas, diet sodas, orange juice and lemonade are significantly more acidic, at 2.0 – 3.0 pH.
Coffee has a multitude of chemical constituents; it’s more complex than wine. It is possible that the acids (of which there are many) are the culprit, but coffee does contain other components that are potentially irritating to the human gut. Despite all the research that’s been done, there is still much that is unknown about how the different elements in coffee react in our bodies.
Acidity in coffee is not related to its pH level, and is actually considered to be a desirable quality. Acidity refers to the flavor profile, similar to the sensations you experience when drinking wine: the tartness, brightness, zing or various regional influences in the bean, that hit both your tongue and your palate when you take a sip.
The acidity of a coffee is partly due to the growing region and partly influenced by the way a bean is processed and roasted. Coffee grown at higher altitudes and in volcanic soils tends to be higher in acidity, and is generally more highly prized. Brazilian, Peruvian, Kenyan and Ethiopian beans falls into this category. The coffees that are lower in acidity, such as Sumatra, are grown at lower elevations.
The roasting process is also very influential. The darker the roast, the lower the level of acid. An Espresso or French roast will be lower in acidity than an American or Viennese roast, for instance. A lower acid (dark) roast will also be “flatter”; remember in coffee, acidity = greater flavor mosaic. Incidentally, the darker roasts, despite tasting stronger, also have a lower caffeine content.
Finally, the brewing method comes into play, too. Cold brewing your coffee is one way to dramatically reduce the acidity of your coffee.
So if it is the acids, or perhaps the caffeine in coffee that are the tummy-torturers for you, there is hope. It could be that switching to a dark roast and/or cold brew coffee is just the ticket.