Priming Sugar Calculator
Dial in bottle-conditioning carbonation by accounting for temperature, sugar type, and style targets.
Use the warmest temperature reached after fermentation (CO₂ escapes at higher temps).
Typical ranges: British ales 1.8, American ales 2.4, Belgian ales 3.0+
Residual CO₂
0.86 volumes
Already present from fermentation
Sugar required
122.9 g
4.33 oz
CO₂ to add
1.64 volumes
For 5.00 gal batch
How to Use This Calculator
Record batch volume and temperature
Measure the final beer volume and note the highest temperature since fermentation ended.
Choose the desired carbonation level
Pick a CO₂ volume suited to the beer style or your preferences.
Weigh priming sugar carefully
Dissolve sugar in boiling water, cool, then gently mix into the bottling bucket before packaging.
Formula
Residual CO₂ = 3.0378 − 0.050062T + 0.00026555T²
Sugar grams = (Target − Residual) × Volumegal × factor
factor = 15.0 for corn sugar, 14.5 for table sugar, 18.9 for DME
Example: 5 gal ale, 68°F, target 2.5 volumes with corn sugar → residual 0.85 → sugar = (2.5 − 0.85) × 5 × 15 = 124 g.
Note: Adjust factor if using other fermentables (e.g., honey ~ 13). Weigh sugar for precision.
Full Description
Bottle conditioning relies on yeast consuming a measured amount of fermentable sugar to produce CO₂ in the sealed bottle. Too little sugar leads to flat beer; too much can cause over-carbonation and safety hazards. This calculator uses the beer temperature to estimate residual CO₂ and calculates the exact priming sugar addition for your target carbonation.
Different sugar sources ferment at different efficiencies. Corn sugar is nearly pure dextrose, table sugar is sucrose, and DME contains unfermentable solids. Choose the sugar type to automatically adjust the fermentable potential and keep carbonation on target.
Tips for perfect conditioning
- Use a digital scale for accurate sugar measurement.
- Boil sugar in a small volume of water for sanitation, then cool.
- Rack beer gently onto the priming solution to mix without oxygenation.
- Store bottles at ~70°F for 2–3 weeks, then chill before opening.
Always handle bottles carefully—over-priming can create bottle bombs. If experimenting with alternative sugars, start with small batches and keep detailed notes for future brews.
Frequently Asked Questions
How accurate is the temperature-based residual CO₂ formula?
It’s a widely accepted model for typical fermentation temperatures. Extreme temps or long cold conditioning may require adjustments.
Can I use honey or maple syrup?
Yes, but the fermentable content varies. Use online references for factors or measure gravity to compute custom values.
What if my beer ends up over-carbonated?
Chill bottles thoroughly, open carefully, and next time reduce the target CO₂ or sugar amount slightly.
Can I bottle condition kegged beer?
Sure. De-gas the beer first, measure temperature, and use this calculator to treat the beer like a typical bottling batch.