With a pH value of 5, black coffee is acidic. Water has a pH of 7 and is considered neutral. Anything lower than 7 is acidic, while anything higher than 7 is alkaline. Bananas have the same pH value of coffee at 5.
"PH" stands for "potential hydrogen" and measures the level of acidity of liquids. A change of 1 on the pH scale means a liquid is 10 times more or less acidic. For example, milk has a pH level of about 6 and is 10 times more acidic than water with a pH value of 7. PH measurements are used in various applications, including engineering, water treatment, agriculture, food science and medicine.