⚖️ Must Weight Calculator
Calculate and adjust must weight for optimal wine fermentation
Must Measurements
Typical range: 18-28°Bx
Desired final alcohol percentage
Results
Enter your must measurements and click Calculate
Must Weight Scale Comparison
| Brix (°Bx) | Specific Gravity | Baumé (°Bé) | Oechsle (°Oe) | Potential ABV |
|---|---|---|---|---|
| 18 | 1.074 | 10.0 | 74 | 9.9% |
| 20 | 1.083 | 11.2 | 83 | 11.0% |
| 22 | 1.092 | 12.3 | 92 | 12.1% |
| 24 | 1.101 | 13.4 | 101 | 13.2% |
| 26 | 1.110 | 14.6 | 110 | 14.3% |
| 28 | 1.120 | 15.7 | 120 | 15.4% |
| 30 | 1.129 | 16.9 | 129 | 16.5% |
Understanding Must Weight Scales
📊 Brix (°Bx)
Used in: USA, Canada, New Zealand, Australia
Measures: Grams of sucrose per 100 grams of solution
Instrument: Refractometer or hydrometer
Formula: 1°Bx ≈ 0.55% potential ABV
⚖️ Specific Gravity (SG)
Used in: Worldwide, especially brewing
Measures: Density relative to water (water = 1.000)
Instrument: Hydrometer
Range: 1.070-1.120 for wine musts
🍇 Baumé (°Bé)
Used in: France, parts of Europe
Measures: Sugar density on Baumé scale
Instrument: Baumé hydrometer
Formula: 1°Bé ≈ 1.8% potential ABV
🇩🇪 Oechsle (°Oe)
Used in: Germany, Switzerland, Luxembourg
Measures: Must weight minus 1000 (SG 1.083 = 83°Oe)
Instrument: Oechsle hydrometer
Classification: German wine quality based on °Oe
🎯 Target Must Weights by Wine Style
Light Table Wine 18-20°Bx 1.074-1.083 10-11% ABV
Standard White Wine 20-22°Bx 1.083-1.092 11-12% ABV
Standard Red Wine 22-24°Bx 1.092-1.101 12-13% ABV
Full-Bodied Red 24-26°Bx 1.101-1.110 13-14% ABV
Late Harvest 28-35°Bx 1.120-1.150 14-18% ABV
Ice Wine/Noble Rot 35-50°Bx 1.150-1.230 10-15% ABV*
📐 Conversion Formulas
Brix to SG:
SG = (Brix / (258.6 - ((Brix / 258.2) × 227.1))) + 1 SG to Brix:
Brix = (((182.4601 × SG - 775.6821) × SG + 1262.7794) × SG - 669.5622) Brix to Baumé:
Baumé = Brix / 1.8 SG to Oechsle:
Oechsle = (SG - 1) × 1000 Potential ABV:
ABV ≈ (Starting Brix - Final Brix) × 0.55 🔬 Measuring Must Weight Accurately
- Temperature: Most hydrometers calibrated at 60°F or 68°F - adjust readings for temperature
- Sample preparation: Filter out solids for accurate hydrometer reading
- Refractometer: Only needs 1-2 drops, faster than hydrometer
- During fermentation: Alcohol skews refractometer readings - use hydrometer instead
- Multiple samples: Test from different parts of tank for homogeneity
- Sanitization: Always sanitize equipment before taking samples
⚠️ Important Considerations
- Yeast alcohol tolerance: Most wine yeasts top out at 14-16% ABV
- Temperature effects: Incorrect temperature can give false readings
- Unfermentable sugars: Not all sugars ferment - actual ABV may be lower
- Residual sugar: Sweet wines have sugar remaining, lowering final ABV
- Regional regulations: Some areas restrict chaptalization or enrichment
- Balance: Higher alcohol isn't always better - consider acid, tannin balance