Hop extract intended for use in beer brewing or elsewhere in the food industry
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).
Hops and hop products intended for use in beer brewing or elsewhere in the food industry
Hop constituents are distributed between an aqueous acidic methanolic phase and diethyl ether. Hop bitter substances extracted with ether are subsequently separated according to their different solubility properties in cold methanol and hexane into fractions: total resins, soft resins and hard resins. The soft resins are further separated according to their capacity to form complexes with lead salts into α-acids (conductometer value) and a β-fraction.
This method describes how to perform sensory analysis of hop-accentuated beers.
beer
Kaltner (2000) developed a score sheet for assessing beers with a strong hop flavor, which on one hand is based on the DLG quality assessment of beer (refer to S.590.53.700 Einzelprobenprüfung zur Qualitätskontrolle von Bier - DLG-Prüfschema für Bier). The criteria aroma, flavor, fullness, liveliness and bitterness are evaluated using a five-point scale in half-point steps, where 5 denotes a pure attribute and 1 indicates major faults. On the other hand, the quality and distinction of the hop aroma and bitterness are assessed. The aroma and flavor of the hop impression are also distinguished. The evaluation is also based on a five-point scale with an intensity of 5 corresponding to the attribute “perfume-like” and 1 to “not perceptible”. Under “quality of the hop aroma” a score of 5 is considered “pleasant” and 1 “unpleasant”. Additionally, the score sheet provides space for describing the sensory impression of the appeal of a particular hop note. The intensity of the bitterness is also evaluated on a five-point scale, and in this case, 5 denotes a very strong impression, and 1 a very weak one.
The appeal of the bitterness has been plotted on a graph and is expressed using the following terms:
rapidly diminishing (low intensity)
fine, harmonious (moderate intensity and pleasantly lingering)
hard (high intensity and fleeting)
lingering (high intensity and persistently lingering)
This method describes how to conduct a simple descriptive test.
beer, beer-based beverages, non-alcoholic beverages, mineral water
This simple descriptive analysis provides a method for articulately communicating sensory attributes. The method can be utilized to formulate a list of attributes for the profile test. The list of attributes must then be statistically corroborated and reference samples employed to ensure that all of the testers identify the same reference substance for each of the given attributes (e.g., rancid butter, sweaty = reference substance butyric acid).
Determination of bittering units in beer, beer-based beverages and wort.
This method is not suitable for beer, beer-based beverages or wort, which contain saccharin, p-hydroxybenzoic acid ester, salicylic acid or sorbic acid.
The bitter substances, primarily iso α-acids, are extracted using iso-octane from the acidified sample, and their concentration in the extract is determined spectrophotometrically [1].