Routine Use of a Programmable Calculator for Computing Alcohol, Real Extract, Original Gravity, and Calories in Beer. K. J. Siebert, The Stroh Brewery Company, One Stroh Drive, Detroit, MI 48226. J. Am. Soc. Brew. Chem. 38:0027, 1980.

Formulas and a calculator program that accurately calculate alcohol, real extract, original gravity, and calories from either refractive index or immersion refractometer scale readings and either specific gravity or apparent extract are explained. Two alternate computational approaches are compared and contrasted with the use of tables. One such program has been successfully used with a programmable printing calculator for routine quality control for more than nine months. This has resulted in increases in speed, operator convenience, and accuracy.

Keywords: Brewing, Calculation, Calories, Density, Formulas, Refractive index, Specific gravity