A precise, professional-grade calculator to determine the exact priming sugar needed for 5-gallon batches. Built for homebrewers who want repeatable carbonation without guesswork—fully accessible, mobile-first, and lightning fast.
Calculator
Choose unit system
Switching units will auto-convert current inputs.
Total beer to be bottled. Includes losses into the bottling bucket. Default is 5.00 gal (18.927 L).
Use the warmest temperature your beer reached post-fermentation. This determines residual CO₂ and prevents over-carbonation.
CO₂ volumes express liters of CO₂ (at STP) dissolved per liter of beer. Typical range: 1.8–3.0 depending on style.
Picking a preset will fill the target field—you can still fine-tune it.
Each sugar yields different CO₂ per gram. The calculator applies a science-backed coefficient for each type.
All fields marked with * are required. Values update automatically as you type.
All calculations are rigorously based on the formulas and data provided by this source. We additionally cross-check the sugar yield coefficients using standard fermentation stoichiometry.
The Formula Explained
For beer temperature T in °F, residual dissolved CO₂ (volumes) is approximated by:
\[ V_{\mathrm{res}}(T_{°F}) = 3.0378 - 0.050062\,T + 0.00026555\,T^{2} \]
Convert Celsius to Fahrenheit before applying the formula: \[ T_{°F} = \frac{9}{5}T_{°C} + 32 \]
- Batch volume: Total beer to be bottled. Accepted in gallons or liters.
- Highest beer temperature: Warmest post-fermentation temperature; drives residual CO₂ estimate.
- Target CO₂ volumes: Desired carbonation level (volumes of CO₂ per liter of beer).
- Sugar type: Priming medium that dictates yield coefficient k_sugar.
- Residual CO₂: Estimated current dissolved CO₂ in volumes.
- Priming sugar (g / oz): Exact sugar mass to add to reach target CO₂.
- Per 12 oz bottle (g): Convenience measure dividing total grams by ~48 bottles in 5 gal (approx.).
How It Works: A Step‑by‑Step Example
Assume a 5.0 gallon batch, warmest beer temperature 68 °F, target carbonation 2.4 volumes, and table sugar (sucrose).
Round to the nearest gram and dissolve in 240–480 mL (1–2 cups) of boiled, cooled water before gently mixing into the beer.
Frequently Asked Questions (FAQ)
Do I use the bottling temperature or the warmest fermentation temperature?
Use the warmest temperature after fermentation. This yields the lowest residual CO₂ and avoids over-carbonation.
Why are sugar amounts different for sucrose and corn sugar?
They have different fermentable content per gram. The calculator applies a coefficient based on fermentation stoichiometry and widely used brewing references.
Is DME reliable for priming?
Yes, but DME contains unfermentables. Our coefficient (≈6.40 g/L/vol) is an average; weigh carefully to prevent under-carbonation.
Can I measure sugar in cups?
We recommend weighing. Cup measurements vary with packing density and humidity and can be off by 10–20%.
How many bottles do 5 gallons fill?
Roughly 48 standard 12 oz bottles (355 mL). Losses may reduce this total slightly.
What if my target is lower than residual CO₂?
You need zero priming sugar. Consider gently degassing or simply accepting a higher carbonation level.
Is there a risk of bottle bombs?
Yes, if you add too much sugar, bottle too early, or use weak bottles. Always confirm fermentation is complete (stable gravity readings) and measure sugar precisely.
Strumento sviluppato da Ugo Candido,. Contenuti verificati da,.
Ultima revisione per l'accuratezza in data: .