This method describes how to determine the extract content of malt used to produce laboratory wort.
Malt intended for use in beer brewing or elsewhere in the food industry
The extract content of malt refers to the compounds from finely ground malt (fine grind), which are brought into solution during a standardized mashing process.
The extract content is determined by the weight ratio sL 20/20 of the wort on the basis of the official sugar tables (Plato tables) at 20 °C. sL 20/20 stands for the weight ratio of a volume of wort at 20 °C to the same volume of water at the same temperature.
Determination of the SGA20/20 submerged weight ratio of a liquid
Wort, beer, beer-based beverages, NAB, beverages, liquid
By precisely weighing the volume of a solution (wort or beer) against the same volume of a reference solution (water) at 20 °C, the relationship of the submerged weights (specific gravity), which are dependent on their buoyancy, is calculated through division and is expressed as SGA20/20 [1].
Determination/calculation of the apparent extract content from the SGA20/20 or the density of a liquid
wort, beer, beer-based beverage, NAB, beverage
Determine the SGA20/20 obtained from pycnometry or the density measured with a precision hydrometer or another device for measuring the density. Using the value from the SGA20/20 measurement or the density from the sugar, alcohol, original gravity and correction table according to GOLDINER/KLEMANN, BLOCK, KÄMPF or a polynomial, determine the apparent extract content of the sample.
Determination/calculation of original gravity, alcohol and real extract content after distillation of beer, beer-based beverages or beverages.
Beer, beer-based beverages, beverages
After distillation of the sample, the original gravity, alcohol and real extract content of the beer in beer-based beverages or other beverages can be determined from the densities of the distillate and residue.
beer, beer-based beverages, beverages
The refraction of a light beam as it passes from an optically less dense (sample liquid) to an optically denser medium (prism) is a function of concentration (alcohol/extract), temperature and wavelength. The density of the test liquid is a function of the concentrations of alcohol and extract content. Therefore, from the refractive index (or alternatively the refractive index nD20 and the density or the SGA20/20, the real extract), the alcohol and original gravity can be determined from nomograms or using regression equations.