Data Source and Methodology
Authoritative Data Sources
- John J. Palmer, How to Brew (4th ed.), Chapter “Priming and Carbonation”, Brewers Publications, 2017. howtobrew.com
- Brewer’s Friend, “Beer Priming Calculator” & residual CO₂ temperature fit. brewersfriend.com
- Lallemand Brewing, “Bottle Conditioning Calculator”. lallemandbrewing.com
All calculations are strictly based on the formulas and data provided by this source.
The Formula Explained
Residual CO₂ (volumes) from temperature (°F):
V_{res}(T_F) = 3.0378 - 0.050062\,T_F + 0.00026555\,T_F^2
Required sugar mass (grams):
m_{sugar} = (V_{target} - V_{res}) \times V_{beer,L} \times k_{sugar}
Per-bottle sugar (grams):
m_{per\_bot} = \dfrac{m_{sugar}}{N_{bottles}} \;\;\; \text{where} \;\; N_{bottles}=\left\lceil\dfrac{1000\,V_{beer,L}}{V_{bottle,mL}}\right\rceil
ksugar is the fermentable-specific factor in g/L per 1.0 CO₂ volume. Defaults used here: dextrose 4.01, sucrose 3.70, DME 6.50, honey 4.25.
Glossary of Variables
- Batch volume (Vbeer,L): Beer volume packaged, in liters.
- Bottling temperature (T): Highest post‑fermentation beer temperature; used to estimate Vres.
- Target CO₂ (Vtarget): Desired carbonation level in volumes of CO₂.
- Residual CO₂ (Vres): CO₂ already dissolved from fermentation, based on temperature.
- ksugar: Sugar factor (g/L per 1.0 volume), varies by fermentable.
- Sugar mass (msugar): Total priming sugar required for the batch.
- Bottle size (Vbottle,mL): Nominal bottle volume in milliliters.
- Nbottles: Estimated number of bottles, rounded up.
How It Works: A Step-by-Step Example
Scenario: 19 L batch at 21 °C (70 °F), American Ale target 2.3 vols, dextrose, 355 mL bottles, no loss.
- Convert temperature to °F: 21 °C → 69.8 °F.
- Residual CO₂:
V_{res} = 3.0378 - 0.050062(69.8) + 0.00026555(69.8)^2 \approx 0.86 - Delta volumes:
\Delta V = V_{target} - V_{res} = 2.3 - 0.86 = 1.44 - Sugar factor for dextrose:
k_{sugar} = 4.01 \; \mathrm{g/(L\cdot vol)} - Total sugar:
m_{sugar} = 1.44 \times 19 \times 4.01 \approx 109.7\ \mathrm{g}(≈ 3.87 oz). - Bottle count:
N = \left\lceil \dfrac{1000\cdot 19}{355} \right\rceil = \lceil 53.5 \rceil = 54 - Per-bottle sugar:
m_{per\_bot} = 109.7/54 \approx 2.03\ \mathrm{g}(≈ 0.072 oz).
We recommend weighing sugar with a scale for best accuracy.
Frequently Asked Questions (FAQ)
How accurate are the sugar factors?
They reflect widely used practical values: dextrose 4.01, sucrose 3.70, DME 6.50, honey 4.25 g/L per 1.0 vol. Actual results can vary slightly by brand and humidity; weigh by grams for consistency.
Should I heat or boil the priming solution?
Yes. Dissolve sugar in a small volume of water and gently heat to sanitize. Cool before mixing with beer to avoid hot-side oxygen pickup or uneven mixing.
How do I avoid uneven carbonation across bottles?
Batch prime: gently rack beer onto the cooled priming solution and stir with sanitized equipment to achieve uniform distribution without introducing oxygen.
What if my beer was cold-crashed?
Use the warmest temperature reached after active fermentation (often before the crash) for residual CO₂. Using fridge temp would overestimate residual CO₂ and under‑prime.
Is there a safe upper limit for CO₂ volumes in bottles?
Standard 12–22 oz beer bottles typically handle up to ~3.0–3.2 vols; some Belgian bottles tolerate more. Always match the bottle to the style and carbonation target.
Can I use table sugar instead of corn sugar?
Yes. Use slightly less by weight (the calculator adjusts automatically). Flavor impact is negligible at typical priming levels.
Last reviewed for accuracy on: .