This method describes the determination of the extract content of malt through the application of a complete extraction technique.
Malt intended for use in beer brewing or elsewhere in the food industry
Since the Congress mash method does not accurately quantify the extract content of malt, an attempt was made to eliminate the sources of error present in the method. The method described below incorporates the procedure for producing a Congress mash according to the EBC, followed by a complete extraction of the dissolved substances with a suitable apparatus. After the extraction is complete, the weight is determined. This method is preferred for determining brewhouse yield (e.g., during brewhouse equipment commissioning tests).
Determination of the fermentation cellar yield in order to monitor brewhouse operations
Wort from the midpoint of chilling/pitching wort
The fermentation cellar yield is calculated using the value determined for the amount of extract contained in a batch of wort relative to the amount of extract present in the raw materials used to produce the wort.
This method describes how to determine the extract content of roasted and caramel (crystal) malt by means of a modified Congress mash method.
Roasted and caramel (crystal) malts intended for use in beer brewing or elsewhere in the food industry
Pilsner malt, of which the moisture content, extract and color are known, is mashed together with roasted or caramel (crystal) malt according to the Congress mash method. The extract content of the roasted or caramel (crystal) malt is determined by taking the analysis values for the pilsner malt into account.
Determination of the fermentable extract in beer and wort
This method is suitable for all types of beer and wort.
Beer or wort is fully attenuated under agitation in an Erlenmeyer flask after yeast has been added. From the difference between the extract content prior to fermentation commencing (original gravity) and after fermentation is complete, the limit of attenuation is calculated.
Real extract minus apparent extract of the fully attenuated beer (from which the alcohol was removed) yields the value for “apparent attenuation”, because during the final stages of attenuation alcohol is produced.
The portion, which has actually been fermented, can be calculated through multiplication by the factor 0.81. This factor is related to the so-called attenuation quotient q [1].
Valid for all non-turbid beers
By incrementally adding increasing amounts of a saturated ammonium sulfate solution to beer, haze appears as a result of protein precipitation. The amount of the ammonium sulfate solution necessary to produce haze is directly proportional to the stability of the beer. The ammonium sulfate precipitation value expresses the ml of saturated ammonium sulfate solution that must be added to 100 ml of beer in order to produce a barely perceptible opalescence.
The Esbach reaction test provides an indication of the physical and chemical stability of beer, particularly for those which have been treated with bentonite [1, 2].
Suitable for all non-turbid beers
Higher molecular weight proteins are precipitated with the Esbach reagent (solution of picric acid and citric acid). The haze that is formed is determined spectrophotometrically.