Determination of the viscosity of beverages
wort, beer, beer-based beverages, NAB, juice, beverages in general
Capillary viscometers measure the kinematic viscosity of Newtonian fluids, unlike falling ball and the rotational viscometers, which directly measure the dynamic viscosity. However, with values for the kinematic viscosity and the density of the test liquid, the dynamic viscosity can be calculated.
The time required for a volumetrically defined amount of fluid (the volume between two marks on the tube of the viscometer) to flow through a capillary of a defined length is measured.
1 square meter per second of a homogenous fluid with a dynamic viscosity of 1 Pa × s and a density 1 kg/m³
The unit for expressing kinematic viscosity (the relationship of viscosity to density = viscoplasticity) is 1 m²/s = 106 mm²/s
The kinematic viscosity is expressed as 1 square meter per second of a homogenous fluid with a dynamic viscosity of 1 Pa × s and a density 1 kg/m³.
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.
Applicable for all (laboratory) worts
The Congress wort is heated in order to inactivate the amylolytic enzymes. Afterwards, 16 g/100 ml yeast is added, and the wort is allowed to completely ferment out in approx. 7 h.
This method describes how to determine the fermentable carbohydrates in wort or in the Congress wort using high performance liquid chromatography.
Applicable for all (laboratory) worts
Fructose, glucose as well as disaccharides and trisaccharides (maltose and maltotriose) are determined using high performance liquid chromatography (HPLC).
Wort or beer is deionized using an ion exchanger. The sample is filtered and concentrated using a solid-phase column and analyzed chromatographically. The concentration of the sugars present in the sample is calculated from the chromatograms obtained by analysis of the calibration solutions.
This method describes how to determine the organic acids in wort and the Congress wort using a cation exchanger.
Applicable for all (laboratory) worts
A cation exchanger based upon a sulfonated, crosslinked styrene/divinylbenzene copolymer is used to determine various organic acids in wort. Due to the high ligand density, the separation mechanism is based upon a combination of ion exclusion, ligand exclusion and steric exclusion; detection is performed using a UV detector.
Suitable for analysis of all (laboratory) wort samples
Iron is measured using the AAS technique by directly aspirating the diluted sample into an acetylene oxygen flame or electrothermally (graphite furnace); the measurement is made at 248.3 nm.