The method describes how to determine the iso-α-acids, α-acids and β-acids in hop extracts and isomerized extracts by means of high-pressure liquid chromatography.
Hop extract and isomerized hop extract intended for use in beer brewing or elsewhere in the food industry
Hop extracts and isomerized hop extracts are dissolved in methanol. The iso-α-acids, α-acids and β-acids are separated using hig-pressure liquid chromatography (HPLC) with gradient elution and measured spectrophotometrically at a wavelength of 270 nm (iso-α-acids) and 314 nm (α-acids and β-acids).
Determination of the total extract in the spent grain through enzymatic digestion
Wet spent grain, dry spent grain
The total extract is obtained through boiling the spent grain followed by enzymatic digestion with technical enzymes (Termamyl 120 L and SAN Super 360 L). The available residual extract represents the difference between total extract and soluble extract.
Determination of the total extract in the spent grain using the diastase method
Wet spent grain, dry spent grain
The total extract is obtained through boiling the spent grain followed by enzymatic digestion with diastase obtained from malt. The available residual extract represents the difference between total extract and soluble extract.
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 soluble extract in wet spent grain obtained by pressing
Wet spent grain
Wet spent grain is pressed using a manual press.
Determination of the soluble extract in the spent grain through rinsing
Wet spent grain, dry spent grain
The soluble extract in the spent grain is determined by rinsing with H2O at 70 °C.