Beer Bottling Calculator (Priming Sugar & Bottle Estimator)

This professional calculator determines the exact priming sugar needed for bottle conditioning by accounting for the beer’s residual CO₂ (temperature-dependent), your target carbonation (volumes of CO₂), the sugar type’s fermentability/yield, and your packaging size. It’s designed for repeatable, competition-grade results.

How to Use

  1. Enter volume of beer and beer temperature (warmest post-fermentation temp).
  2. Select a style preset or set your target CO₂.
  3. Choose your sugar type (dextrose/sucrose/DME/honey).
  4. Set your bottle size; we estimate bottle count and per-bottle sugar if you prefer dosing.
  5. Use Batch prime for best consistency: dissolve sugar in boiled & cooled water, gently rack beer onto the solution, then bottle.

Formulas

Residual CO₂ (vol) as a function of beer temperature \(T\) in °F (ASBC fit):
\( V_{\mathrm{res}} = 3.0378 - 0.050062\,T + 0.00026555\,T^2 \)

Temperature unit conversion:
\( T_{\mathrm{F}} = 32 + \frac{9}{5}T_{\mathrm{C}} \)

CO₂ to add (volumes):
\( \Delta V = \max(0, V_{\mathrm{target}} - V_{\mathrm{res}}) \)

Priming sugar mass (grams):
\( m = \Delta V \cdot V_{\mathrm{beer}}^{(L)} \cdot k_{\mathrm{sugar}} \)
where the empirical yield constants \(k_{\mathrm{sugar}}\) are:
– Dextrose (corn sugar): \(k \approx 3.86\,\mathrm{g\cdot L^{-1}\cdot vol^{-1}}\)
– Sucrose (table sugar): \(k \approx 3.46\,\mathrm{g\cdot L^{-1}\cdot vol^{-1}}\)
– DME (dry malt extract): \(k \approx 6.85\,\mathrm{g\cdot L^{-1}\cdot vol^{-1}}\)
– Honey (avg.): \(k \approx 4.16\,\mathrm{g\cdot L^{-1}\cdot vol^{-1}}\)

Glossary

Volumes of CO₂

Liters of CO₂ (at STP) dissolved per liter of beer. Typical ales: 2.2–2.6 vol; German wheat: 2.6–3.0+ vol.

Residual CO₂

CO₂ already dissolved from fermentation, determined primarily by the warmest beer temperature prior to bottling.

Priming Sugar

Fermentable added at bottling to produce CO₂ in sealed bottles. Different sugars have different yields.

Worked Example

Scenario: 20 L of American Pale Ale at 20 °C, target 2.5 vol CO₂, using dextrose, 500 mL bottles.

  1. Convert 20 °C → \(T_F = 68\) °F. Compute residual: \(V_{res} \approx 3.0378 - 0.050062·68 + 0.00026555·68^2 \approx 0.85\) vol.
  2. \(\Delta V = 2.5 - 0.85 = 1.65\) vol to add.
  3. Sugar mass \(m = 1.65 × 20 × 3.86 \approx 127.4\) g (≈ 4.49 oz).
  4. 500 mL bottles → ≈ 40 bottles. Per-bottle dosing ≈ \(127.4 g / 40 \approx 3.2\) g each.

Best Practices & Safety

  • Use the warmest post-fermentation temperature to avoid over-carbonation.
  • Batch priming is more consistent than per-bottle dosing.
  • Boil the priming solution (e.g., sugar in 250–350 mL water per 20 L), cool, then rack beer on top.
  • Gently invert the bottling bucket to mix; avoid splashing to minimize oxygen pickup.
  • High-carb styles (> 3.0 vol) require thick-glass bottles rated for higher pressure.

Authoritative Sources

  • ASBC (American Society of Brewing Chemists) CO₂ solubility/carbonation tables and common polynomial fits.
  • Palmer, J. (2017). How to Brew, 4th ed. Brewers Publications – priming fundamentals & style ranges.
  • Lallemand Brewing – Bottle Conditioning Guide (CO₂ targets, process control).

FAQ

Which sugar should I use?

Dextrose and sucrose are most predictable. DME has lower fermentability (higher grams required). Honey varies by source and moisture; use as an approximation or weigh carefully.

Why does temperature matter?

Colder beer holds more CO₂. Warmer beer retains less residual CO₂, so you need more priming sugar to reach the same target carbonation.

Is per-bottle dosing safe?

Yes if weighed accurately, but batch priming is more consistent and reduces variance that can lead to under- or over-carbonation.

How much water for the priming solution?

Enough to dissolve the sugar fully without adding significant volume. A practical range is 10–20 mL per 10 g sugar (≈ 200–300 mL per 20 L batch).