Which is more acidic vinegar or grapefruit juice?

Vinegar is more acidic than grapefruit juice. Vinegar typically has a pH of around 2.4 to 3.4 due to its acetic acid content, while grapefruit juice has a pH of about 3.0 to 3.8, primarily from citric acid. Therefore, vinegar is generally considered to be more acidic than grapefruit juice.