pH value: strength, not amount

The standard

A measured acid strength names its basis: the pH value is determined electrochemically at a reference temperature, not calculated from the amount of acid.

Criteria

• The value names the reference temperature of the measurement
• It comes from electrochemical measurement, not from calculation
• It describes the strength of the acid, not its titratable amount
• It is stated separately from total acidity

Distinction

pH value ≠ total acidity: total acidity quantifies the amount of titratable acids, the pH value their effective strength. A wine can contain much acid and still show a high pH value if that acid dissociates weakly. Only both together, not the measured acid strength alone, describe a wine's acid profile.