Molecular sulfur: the active form
The standard
The pH-related efficacy measures the protection of a wine by the molecular fraction, not by the total amount added.
Criteria
- Protection is measured by the molecular fraction, not by the total dose
- The pH determines which fraction is present in active form
- Equal amounts yield less effect at higher pH
- The target is the effect, not the dose
Distinction
Molecular sulfur ≠ free sulfur: free sulfur also includes dissolved, inactive forms, molecular sulfur only the active fraction. Molecular sulfur ≠ total sulfur: total sulfur also includes the bound forms, which do not protect. The pH-related efficacy separates amount and effect.