This method describes the fluorimetric determination of high-molecular weight β-glucans in laboratory worts.
Suitable for all types of (laboratory) worts
The fluorochrome Calcofluor forms a complex with high molecular weight β-glucans (molecular weight greater than 5 kDa). Complex formation results in an increase in fluorescence; however, this fluorescence is extremely unstable due to photochemical degradation.
Reproducible measurements for fluorescence and determination of β-glucan are possible through measurement in an automatic analysis system based on flow injection (flow-injection analysis). The apparatus is calibrated using purified barley β-glucan standard solutions.
The method describes the analysis for optically evaluating the (Congress) mash.
Malt intended for use in beer brewing or elsewhere in the food industry
Optical evaluation of the appearance of (Congress) wort
Malt intended for use in beer brewing or elsewhere in the food industry
The value of pH is defined as the negative decadal logarithm of the concentration of hydrogen, or more precisely, hydronium ions:
\(\text{ pH }=-\log{ c_{ H_{ 3 }O^{ + } } }\)
The pH scale, ranging from 0–14, is based on the dissociation equilibrium.
The pH value of a liquid is commonly determined with a pH measurement device consisting of the measurement electrode (glass) and the reference electrode (e.g., silver/silver chloride electrode), which is connected to a signal amplifier and a display instrument. The device is calibrated using standard buffer solutions.
The pH reading displayed is determined through the difference in electrical potential between the reference solution in the electrode and the solution being measured.
Generally, a pH measurement system is used, in which the measurement and reference electrodes are combined to form a single unit.
Malt intended for use in beer brewing or elsewhere in the food industry
The determination of the color of the Congress wort is carried out by measuring the absorbance of the wort at 430 nm and then multiplying the value by a specified factor.
Malt intended for use in beer brewing or elsewhere in the food industry
After boiling for two hours on a reflux condenser, the wort is clarified using membrane filtration. The color is measured with a spectrophotometer.
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).