Professional Priming Sugar Calculator (Bottle Conditioning)
This tool computes the exact priming sugar dose by accounting for residual CO₂ (temperature-dependent), sugar chemistry (CO₂ yield by type), batch volume, and style-appropriate target carbonation. It implements the widely adopted temperature-to-CO₂ relationship and aligns with authoritative brewing references.
How to use
- Units: Choose Metric or US.
- Batch volume: Measure the actual beer in the bottling bucket.
- Beer temperature: Enter the highest temperature the beer reached post-fermentation (peak).
- Style preset: (Optional) Select a style to see a recommended range, then set your target volumes.
- Sugar type: Pick sucrose or dextrose (anhydrous/monohydrate). For DME/honey, you can tune fermentability/density.
Formulas used
Residual CO₂ from temperature (volumes):
\\[ V_{res}(T_{^{\circ}F}) = 3.0378 - 0.050062\\,T + 0.00026555\\,T^{2} \\]
Use the highest post-fermentation temperature (°F). This approximation is widely referenced in pro/homebrew literature.
CO₂ to add (volumes): \\( V_{add} = \\max(0, V_{target} - V_{res}) \\)
Sugar mass from desired CO₂ (sucrose baseline):
\\[ m_{sugar} = V_{add} \\times V_{beer\\,(L)} \\times k_{sugar} \\]
with constants per sugar (grams per liter per 1 volume CO₂):
- Sucrose: \\(k=3.81\\,\\tfrac{g}{L\\cdot vol}\\)
- Dextrose (anhydrous): \\(k=4.00\\)
- Dextrose (monohydrate): \\(k=4.40\\) (≈ +9–15% vs sucrose)
- DME (light): \\(k=\\tfrac{3.81}{f}\\), with fermentability \\(f\\in[0.60,0.75]\\) → typically \\(k\\approx 5.1\\)–\\(6.35\\)
- Honey: treat as sucrose-like CO₂ yield on the fermentable fraction; convert to mL via density (≈1.42 g/mL).
Worked example
Goal: 19 L American ale at 20 °C targeting 2.4 volumes, using dextrose monohydrate.
- Convert 20 °C → 68 °F; \\(V_{res}=3.0378-0.050062\\times68+0.00026555\\times68^{2}\\approx0.85\\,vol\\).
- \\(V_{add}=2.4-0.85=1.55\\,vol\\).
- \\(m=1.55\\times19\\times4.40=129.8\\,g\\) corn sugar (≈ 4.58 oz).
Style carbonation reference
| Style | Volumes CO₂ |
|---|---|
| American ales | 2.2–3.0 |
| British ales | 1.5–2.2 |
| European lagers | 2.4–2.6 |
| Belgian ales | 2.0–4.5 |
| German weizens | 2.8–5.1 |
Glossary
- Volume of CO₂ (vol): Unitless ratio; 1 vol means 1 L CO₂ dissolved per 1 L beer at STP.
- Residual CO₂: CO₂ already dissolved after fermentation, mainly set by the beer’s peak temperature.
- Fermentability (DME): Fraction that ferments to CO₂/ethanol; varies by brand and yeast.
Authoritative data sources
- Residual CO₂ equation & usage (peak temperature): Brewer’s Friend Priming Calculator notes & community docs; also cited in packaging literature. :contentReference[oaicite:0]{index=0}
- Style carbonation ranges & sugar yield tables: BYO Carbonation Priming Chart (Sections A–C). :contentReference[oaicite:1]{index=1}
- Dextrose monohydrate water content (~9%) and impact: BYO “Priming with Sugar”. :contentReference[oaicite:2]{index=2}
- DME typical fermentability (~75%): BYO “Brewing Sugars & How To Use Them”; BrewCabin DME calc discussion. :contentReference[oaicite:3]{index=3}
- Alternative pro calculators for cross-checking: Hopsteiner CO₂/Priming Calculator; Northern Brewer. :contentReference[oaicite:4]{index=4}
FAQ
Which temperature should I enter?
Use the highest temperature your beer reached after fermentation. Cold-crashing later does not increase residual CO₂ back up. :contentReference[oaicite:5]{index=5}
Why does sucrose need less mass than corn sugar?
Dextrose monohydrate includes crystal water (~9% by mass) and yields slightly less CO₂ per gram than sucrose; therefore you need ~9–15% more by weight. :contentReference[oaicite:6]{index=6}
Is DME recommended for priming?
It works but is slower and less predictable due to variable fermentability; most pros prefer sucrose or dextrose for consistency. :contentReference[oaicite:7]{index=7}