Molecular SO2 Calculator
Molecular SO2 Calculator
The molecular so2 calculator is used in winemaking to compute the precise amount of molecular sulfur dioxide (SO2) present in wine or other beverages.
- Total SO2: 85 mg/L
- pH: 3.65
- Temperature: 20°C
- Calculated Molecular SO2: 0.48 mg/L
White Wine Analysis
- Total SO2: 120 mg/L
- pH: 3.25
- Temperature: 15°C
- Calculated Molecular SO2: 0.72 mg/L
Sparkling Wine Analysis
- Total SO2: 150 mg/L
- pH: 3.15
- Temperature: 12°C
- Calculated Molecular SO2: 0.85 mg/L
The calculator considers multiple factors, including the wine’s pH level, total SO2, and temperature, to determine the active molecular SO2 concentration.
Molecular SO2 Calculation Formula
The molecular SO2 is calculated using the Henderson-Hasselbalch equation, modified for wine applications:
Molecular SO2 = Total SO2 ÷ (1 + 10^(pH - 1.81))
If you have:
- Total SO2 = 100 mg/L
- pH = 3.4
The calculation would be:
Molecular SO2 = 100 ÷ (1 + 10^(3.4 - 1.81))
= 100 ÷ (1 + 10^1.59)
= 100 ÷ (1 + 38.90)
= 2.51 mg/L
How to Calculate Molecular SO2?
To accurately calculate molecular SO2, follow these essential steps:
- Measure Total SO2: Use a reliable method such as Ripper titration or aeration-oxidation to determine total SO2 in mg/L.
- Determine pH: Measure the wine’s pH using a calibrated pH meter.
- Consider Temperature: Note that temperature affects the dissociation constant, though the standard formula assumes room temperature (20°C).
- Apply the Formula: Use the Henderson-Hasselbalch equation with your measurements.
Analyzing a Chardonnay sample:
- Measured total SO2: 95 mg/L
- pH reading: 3.35
Using the formula:
Molecular SO2 = 95 ÷ (1 + 10^(3.35 - 1.81))
= 95 ÷ (1 + 10^1.54)
= 95 ÷ (1 + 34.67)
= 2.74 mg/L