Fermentation Science, Brewing & Beverage QC
Brewing Plato, Real Attenuation & Balling ABV Formula
Calculate Apparent Attenuation (P_o - P_a)/P_o, Carl Balling’s Real Extract RE = 0.1808*P_o + 0.8192*P_a, Real Degree of Fermentation (RDF), and Finished Beer Alcohol by Volume (% ABV).
Correct hydrometer ethanol buoyancy distortion with Carl Balling’s Real Extract!
When brewer’s yeast ferments maltose into ethanol (specific gravity 0.794 < water 1.000) and CO2 gas, low-density ethanol makes a brewer’s hydrometer sink deeper than unfermented residual sugars warrant! Consequently, Apparent Extract P_a (°Plato) understates true residual dissolved solids, inflating Apparent Attenuation AA = (P_orig - P_a) / P_orig by ~22%! Carl Joseph Napoleon Balling’s foundational zymotechnology stoichiometry (standardized by ASBC Beer-4) recovers true residual sugar mass as Real Extract RE (°P) = 0.1808 * P_orig + 0.8192 * P_a, Real Degree of Fermentation RDF = (P_orig - RE) / P_orig = 0.8192 * AA, Alcohol by Weight ABW_% = (P_orig - RE) / (2.0665 - 0.010665 * P_orig), and Alcohol by Volume ABV_% = ABW_% * (Final_SG / 0.794)!
Verify in a brewhouse cellar QC log—Original_Wort_Extract P_orig = 12.5 °Plato (B2), Apparent_Final_Extract P_a = 2.5 °Plato (B3), and Finished_Beer_SG = 1.010 (B4): Apparent Attenuation is (12.5 - 2.5) / 12.5 = 0.8000 (80.00% in E2); Balling Real Extract RE is 0.1808 * 12.5 + 0.8192 * 2.5 = 2.260 + 2.048 = 4.308 °Plato (E3); Real Attenuation RDF is (12.5 - 4.308) / 12.5 = 0.6554 (65.54% in E4); and Finished ABV_% equals (8.192 / 1.9331875) * (1.010 / 0.794) = 5.39% ABV (E5)!
| ASBC / Balling Cellar QC Metric (P_orig=12.5 °P, P_app=2.5 °P, Final SG=1.010) | Formula | Verified Output |
|---|---|---|
| Apparent Attenuation (AA) | (P_orig - P_app) / P_orig | 0.8000 (80.00% Hydrometer) |
| Balling Real Extract RE (°Plato) | 0.1808 * P_orig + 0.8192 * P_app | 4.308 °P (True Residual Solids) |
| Real Attenuation (RDF) | (P_orig - RE) / P_orig | 0.6554 (65.54% True Sugar Drop) |
| Finished Alcohol by Volume (% ABV) | ABW_% * (Final_SG / 0.794) | 5.39% ABV (0.00% @ P_app=12.5) |
Balling Real Extract & % ABV Stoichiometric Formula
Validate plausible wort extract 0 < P_orig <= 40, fermented extract P_a <= P_orig (P_a can dip slightly negative down to -2 °P in ultra-dry brut beers!), and positive Final_SG!
=LET(p_or, B2, p_ap, B3, sg_f, B4, IF(OR(p_or <= 0, p_or > 40, p_ap > p_or, p_ap < -3, sg_f <= 0.98, sg_f > 1.2), "Invalid Wort Gravity", LET(re_p, 0.1808 * p_or + 0.8192 * p_ap, ab_w, (p_or - re_p) / (2.0665 - 0.010665 * p_or), ROUND(ab_w * (sg_f / 0.794), 2))))Unfermented pitched Wort Identity Check (P_app = 12.5 °P)
Set Apparent_Extract B3 = 12.5 (= P_orig before yeast lag phase ends): Real Extract equals 12.500 °P, both AA and RDF equal 0.0000, and ABV equals 0.00%!
=IF(ISTEXT(E5), E5, ROUND((B2 - E3) / B2, 4))Try the example
Use the original values or change them to test your understanding.