Fast, Accurate Measurement of Free Sulfur Dioxide — No Equipment Required The Accuvin Free SO₂ Test Kit provides a fast, reliable way to measure free sulfur dioxide (SO₂) in both red and white wines, as well as must. Designed for real-world winery conditions, this test requires no sample preparation, no instruments, and no pretreatments—delivering actionable results in just minutes.
Key Benefits
- Measures FREE sulfur dioxide only — the most effective form of SO₂ for wine preservation
- Suitable for red and white wines, including colored and turbid sample.
- No filtration, pretreatment, or adjustments required
- No lab equipment or instrumentation needed
- Results in minutes, ideal for cellar decisions
- Works across a wide pH range
Why Measure Free SO₂? Total sulfur dioxide (Total SO₂ = Free + Bound) is not a reliable indicator of preservative effectiveness. Only free SO₂ actively protects wine against oxidation and microbial spoilage.
- Bound SO₂ can be 30–70% less effective as a preservative
- The amount of bound SO₂ changes over time, reducing protection even if total SO₂ appears adequate
- SO₂ effectiveness is pH-dependent:
- Low-pH wines require less free SO₂
- High-pH wines require significantly higher free SO₂ levels to achieve the same protection
This test measures FREE SO₂ only, giving winemakers the information that actually matters for wine stability and aging.
Test Ranges Included Each kit includes both test ranges:
- Low Range: 0–40 ppm (green cap)
- Typically used for wines with pH ≤ 3.6
- High Range: 40–130 ppm (red cap)
- Common for sweet wines and wines with pH ≥ 3.7
All kits contain a 1:4 ratio of high-range to low-range tests.
What’s Included
-Pre-measured test tubes with rehydration solution
-Low-range and high-range test reagents
-Samplers matched to kit size
-Color comparison chart for result interpretation
Detailed Instructions
Samples of wine or must are used as-is. The Accuvin Free SO₂ test minimizes interference from colored and turbid samples—no filtration or color-removal agents required.
- Pour clear liquid from the tube with the black cap into the reagent tube (green or red cap).
- Cap and shake until powder is fully dissolved (≈1 minute).
- Aspirate sample using the provided sampler (or pipette set to 91 µL).
- Dispense sample into the reagent tube and recap immediately.
- Shake and allow 5 minutes for color development.
- Compare tube color to the chart against a white background. Read under incandescent or natural light for best accuracy.
Storage & Shelf Life
- Store below 80°F (27°C)
- Keep out of direct sunlight
- Product remains effective until the expiration date printed on the container (10 months from manufacture)
