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Wine SO2 Management Calculator

Molecular SO₂ Formula:

\[ [SO₂] = \frac{k \times FSO₂}{1 + 10^{(pH - pKa)}} \]

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mg/L

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1. What is a Wine SO₂ Management Calculator?

Definition: This calculator estimates the molecular SO₂ concentration in wine based on free SO₂, pH, and other parameters.

Purpose: It helps winemakers determine the effective antimicrobial and antioxidant protection in their wines.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ [SO₂] = \frac{k \times FSO₂}{1 + 10^{(pH - pKa)}} \]

Where:

Explanation: The formula calculates the equilibrium concentration of molecular SO₂, which is the active antimicrobial form.

3. Importance of Molecular SO₂ Calculation

Details: Molecular SO₂ is critical for wine stability. A concentration of 0.5-0.8 mg/L is typically needed for microbial stability.

4. Using the Calculator

Tips: Enter the free SO₂ (mg/L), wine pH (default 3.2), conversion factor (default 0.5), and pKa (default 1.81). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is pH important in SO₂ management?
A: pH dramatically affects SO₂ equilibrium - lower pH means more molecular SO₂ at a given free SO₂ level.

Q2: What's a typical target molecular SO₂ level?
A: Generally 0.5-0.8 mg/L for microbial stability, though this depends on wine type and condition.

Q3: When would I change the conversion factor?
A: The 0.5 factor is standard, but some winemakers adjust based on specific conditions or measurements.

Q4: How do I measure free SO₂?
A: Free SO₂ is typically measured using aeration-oxidation or other analytical methods.

Q5: Does temperature affect this calculation?
A: Temperature slightly affects the equilibrium, but pH has a much greater impact in normal winemaking ranges.

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