Hops and hop products intended for use in beer brewing or elsewhere in the food industry
After extraction with toluene, the α-acids and β-acids in the hops and hop pellets are determined using spectrophotometry.
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 iso-α-acids, α-acids and β-acids in beer, beer-based beverages and wort
Suitable for all beer, beer-based beverages and wort
iso-α-Acids (isohumulones), α-acids (humulones) and β-acids (lupulones) are chromatographically separated using this method.
The bitter substances are chromatographically separated by means of RHPLC. The humulones and lupulones are detected at 314 nm, whereas the iso-α-acids are detected at 270 nm.
Equipment
Analytical balance, ± 0.0001 g
Water bath, 20 °C
Ultrasound bath
Centrifuge, 750 g
Vials, crimp caps, crimping tool
Disposable syringes, 20 ml
Syringe filter, 0.45 µm, PTFE
High performance liquid chromatography set up for gradient operations, column oven 35 °C, UV-VIS detector (270 nm and 314 nm)
High pressure liquid chromatograph and UV-VIS detector, equipped for gradient operation
HPLC column, Machery & Nagel CC 125 / 4 Nucleodur 100 5 C18 EC or a comparable column
Graduated cylinder, 1000 ml, 50 ml
Beaker, 50 ml
Volumetric flasks, 100 ml, 50 ml
Volumetric pipettes, 30 ml, 10 ml
Erlenmeyer flask, 100 ml
This method describes how to perform sensory analysis using the DLG Quality Assessment scheme for beer.
beer
According to the DLG scheme of sensory evaluation for beer, the criteria aroma, flavor, fullness, liveliness and the quality of the bitterness are each evaluated on a five-point scale. Any faults in the aroma or flavor are to be described, although a number of descriptors are already provided on the form. The fullness is assessed in accordance with the parameters of the particular beer style. In evaluating the bitterness, quality is of prime importance, not intensity.
The method describes the procedure for conducting a taste test according to the DLG tasting scheme for beer-based beverages.
Beer-based beverages
The form for the sensory analysis of beer-based beverages as part of the DLG Quality Assessment for Beer is provided for evaluating the following criteria:
Aroma:
Products are considered to be flawless if they possess pure, clean, typically fruity aromas. If a product is overly aromatized and/or oxidized or stale, points should be subtracted from its score.
Purity of Flavor:
A pure, clean, aromatic flavor is also desirable here, and if coupled with a well-balanced sugar to acid ratio, a perfect score is given. If a product is overly aromatized, exhibits off-flavors or is out of balance, i.e. if one of the relevant building blocks (sweet, sour, bitter) central to the flavor of a beer-based beverage is too pronounced, then this defect should be recorded on the form.
Liveliness:
The liveliness is assessed according to the five-point scale, the upper and lower limits of which are designated as “very lively” (5) to “very flat” (1).
Harmony:
The overall impression is evaluated under “harmony”.
This method describes the procedure for conducting a taste test using the DLG tasting scheme for various types of water.
Water, table water, mineral water, water with added aroma
The DLG Score Sheet for Water concentrates primarily on the attributes of aroma and flavor. The appearance is evaluated for possible aberrations through verbal remarks.
Aroma
The highest number of points is awarded for a pure aroma impression without off-aromas.
A lower score is given for the evaluations “still pure” or “off-aroma”, whereby the latter must be accompanied by a specific description.
In extreme cases, the product can be classified as “not able to be evaluated”. Additional documentation of off-aromas can be recorded under the “other faults” section.
Flavor
From the perspective of the DLG, a water sample will receive the highest number of points when it tastes “pure, typical” and “balanced”. Deviation from these attributes, the absence of freshness, and also a limited, one-sided character accompanied by off-flavors should result in lower scores.
Due to the nature of their very hedonistic and general character, the terms “not completely true to style”, “not completely fresh” and “not completely balanced” are difficult to use objectively.