Calculateur de Degré d'Alcool de Bière Gratuit
Calculez le degré d'alcool (ABV) de votre bière à partir des densités initiale et finale.
ABV
5.25 %
Formule
## How to Calculate Beer ABV ### Formula **ABV = (OG - FG) x 131.25** This is the standard homebrewing formula. OG (original gravity) is measured before fermentation, and FG (final gravity) is measured after fermentation is complete. ### Apparent Attenuation **AA = (OG - FG) / (OG - 1) x 100%** Attenuation measures what percentage of the available sugars were fermented. Most beer yeasts achieve 65-80% apparent attenuation. ### Taking Gravity Readings Use a hydrometer or refractometer. Hydrometers are calibrated to 60°F; adjust for temperature differences. Refractometer readings after fermentation need a correction factor because alcohol changes the refraction.
Exemple Résolu
A pale ale with OG 1.050 and FG 1.010.
- 01ABV = (1.050 - 1.010) x 131.25 = 5.25%
- 02Attenuation = (1.050 - 1.010) / (1.050 - 1) x 100 = 80%
- 03This is a well-attenuated beer at a standard strength.
Questions Fréquentes
What is a normal original gravity?
Light beers: 1.030-1.040. Standard ales and lagers: 1.040-1.060. Strong ales: 1.060-1.080. Barleywines and imperial stouts: 1.080-1.120+.
Why is my final gravity too high?
Common causes: fermentation temperature too low, not enough healthy yeast, or too many unfermentable sugars. Warm the beer to the upper end of the yeast range and swirl gently. If FG is stable for 3 days, fermentation is done.
Is this formula accurate for high-gravity beers?
The simple formula works well up to about 7% ABV. For stronger beers, the alternate formula ABV = (76.08 x (OG - FG) / (1.775 - OG)) x (FG / 0.794) is more accurate.
Apprendre