Acid is an important component of many foods, contributing to human safety as well as desirable flavor. The usual measure of acid level in a food is pH, defined as the negative logarithm of the concentration of hydrogen ions, expressed as gram equivalents per kilogram (essentially, molar concentration). A value of 7 indicates neutrality and is found for pure water. Lower values indicate acidity, and higher values than 7 indicate basicity. The scale runs from 0 to 14. Few foods have values much a…