The method is suitable for beer brewed to any original gravity or to any alcohol content.
Volatile compounds in beer are concentrated through distillation and extracted with dichloromethane. The solvent phase is analyzed with a gas chromatograph. The linearity of the detector and the determination of the concentrations of analytes in the sample are achieved by using multiple concentration levels within the relevant range and through evaluation of the relative area under the peaks.
Determination of copper content in beer
This method is also suitable for dark and turbid beers. The turbidity particles must be evenly distributed before sampling.
This method is based on the formation of a yellowish-brown, (insoluble in aqueous medium) copper (II) chelate with zinc benzyl dithiocarbamate (ZDBT), a compound that may be extracted with trichloroethane.
The sample is extracted with petroleum ether in a Soxhlet apparatus equipped with a reflux condenser; the solvent is evaporated and the crude fat residue weighed.
The gelatinization temperature can be determined using a rotary viscometer (e.g., Amylograph or Viscograph, Brabender GmbH & Co. KG, Germany [4] or a Rapid-Visco-Analyser, RVA, Perten Instruments, a PerkinElmer Company, USA [8]).
A suspension consisting of a finely ground sample and water is produced, whose precise mixing ratio should correspond to the analysis protocol for the adjunct in question. However, since for many cereals and pseudocereals no official analysis protocol exists, the initial weight for the adjuncts listed in table 2 has been determined empirically [3].
Once the suspension is prepared it is attempered according to a pre-programmed temperature/time program, and the viscosity is determined on a continuous basis by means of a rotor and a rotary torque measurement (fig. 1). When gelatinization begins, an increase in the viscosity is registered, and the corresponding sample temperature is defined as the gelatinization temperature. The standard evaluation criterion (PT) is a viscosity increase of at least 24 cP (≙ mPas) within six seconds.
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
visual assessment
This method describes how to evaluate the degree of contamination present in a lot of barley as part of the visual and manual inspection process.
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
Visual inspection for the presence of foreign grain or contaminants. Also refer to R-110.22.011 Sortierung von Gerste.