This method describes the determination of four hop aroma compounds found in hops and hop products using gas chromatography.
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
The hop oil obtained through steam distillation (refer to links) is dissolved in an organic solvent, separated into its components by means of gas chromatography and determined with a flame ionization detector. The contents are expressed as a percentage of the area of each component compared to the overall area of the peak.
Whole hops intended for use in beer brewing or elsewhere in the food industry
Evaluation of the appearance of hop cones is performed through visual and manual inspection.
Whole hops intended for use in beer brewing or elsewhere in the food industry
Evaluation of the appearance of hop cones is performed through visual and manual inspection.
Whole hops intended for use in beer brewing or elsewhere in the food industry
Evaluation of the appearance of hop cones is performed through visual inspection and sensory assessment.
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
A reliable sampling method for whole hops and hop products is a prerequisite for obtaining suitable material for analysis. The effort involved in collecting the sample depends upon how uniform the hop product is.
This method describes how to determine iso-α-acids, α-acids and β-acids in isomerized pellets by means of reverse phase high pressure liquid chromatography (RP-HPLC).
Isomerized pellets intended for use in beer brewing or elsewhere in the food industry
The bitter substances in isomerized hop pellets contain a substantial amount of iso-α-acids; however, in addition to these, non-isomerized α-acids and β-acids are also present. In order to determine their content, a specific method is required.
After milling, the substances in question are extracted from the isomerized pellets using a diethyl ether/methanol mixture and a hydrochloric acid solution. The iso-α-acids, α-acids and β-acids dissolved in the ether phase are separated using reversed-phase high-performance liquid chromatography (RP-HPLC) and an elution gradient. They are then measured spectrophotometrically at wavelengths of 270 nm (iso-α-acids) and 314 nm (α-acids and β-acids).