Reduction Propensity: Predisposition, Not a Verdict
The standard
A nitrogen-based risk forecast derives the propensity from the must's available yeast-assimilable nitrogen and the chosen yeast. Low nitrogen measurably raises the risk, independent of grape variety.
Criteria
- The must's nitrogen level is known before fermentation
- The yeast strain is chosen with its sulfur formation in mind
- The closure choice accounts for the expected oxygen supply
- The assessment happens before, not after, a fault is found
Distinction
Reduction propensity ≠ reduction: propensity is a predisposition, reduction its actual occurrence. Reduction propensity ≠ wine fault: a high propensity is manageable and not a foregone fault. Without a nitrogen-based risk forecast, the cause of a sulfur note stays undetermined.