I have always noticed, on various lists containing the pH values of common foods, that dried loose-leaf black tea is slightly alkaline (~7.2), and one of the most alkaline drinks. At the same time, if a drink black tea I usually get acid reflux and this has always puzzled me.
I recently stumbled upon the definition of acid-forming foods, which are supposed to create an acidic environment in the stomach, even if they are not by themselves acidic.
Can someone explain to me the physiology/biochemistry of this, and how do I differentiate between acid-forming and acidic foods?
Also, does the fact that black tea has been through a process of oxidation play a role in its behaviour?