The method describes how to determine the viscosity of the laboratory wort using various kinds of falling ball viscometers.
Suitable for all worts and mashes
The amount of time required for a special ball to fall while sinking through a glass tube filled with a test fluid between two marks is measured. The precision of this method is increased if the time is measured using a photoelectric beam to an accuracy of 0.01 s, rather than manually with a stop watch.
The method describes how to determine the viscosity using a micro viscometer (e. g. Lovis).
Suitable for all worts and types of mash.
The measuring principle of the Lovis micro viscometer is based on the Höppler “Falling Ball Viscometer”. A ball of known dimension rolls through a closed capillary, which is inclined at a defined angle. Inductive sensors detect the ball along an exactly defined distance of approximately 100 mm or 25 mm. The rolling time is measured by the instrument and is used for dynamic viscosity calculation. The temperature is precisely regulated by thermoelectric Peltier elements and checked by a Pt-100 temperature sensor. A temperature accuracy of ±0.02 °C and repeatability of ±0.005 °C can be reached.
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.
Determination the viscosity in beverages
wort, beer, beer-based beverages, juices, beverages in general
The amount of time required for a special ball to fall while sinking through a glass tube filled with a sample liquid between two marks is measured. The precision of this method is increased if the time is measured using a photoelectric beam to an accuracy of 0.01 s, rather than manually with a stopwatch.
Determination of the viscosity of beverages using a micro-viscometer.
Wort, Beer, Mixed beer beverages, Non-alcoholic soft drinks, Juices, Beverages in general
The measuring principle of the micro viscometer is based on the Höppler "Falling Ball Viscometer". A sphere of known dimension rolls through a closed capillary inclined at a defined angle. Inductive sensors detect the ball over a precisely defined distance of approx. 100 mm or 25 mm. The rolling time is measured by the device and used for dynamic viscosity calculation. The temperature is precisely controlled by thermoelectric Peltier elements and checked by a Pt100 temperature sensor. A temperature accuracy of ± 0.02 °C and a repeatability of ± 0.005 °C can be achieved.
Applicable for all (laboratory) worts
The quantitative determination described here is based upon a separation of analytes using reverse phase chromatography after pre-column derivatization and detection with fluorescence detection.
Aside from the quantitative determination of the individual amino acids (methods using an ion exchanger, HPLC, GC), cumulative methods of determination are customary. However, these methods also measure NH4+ ions and amines to some degree.
With methods involving color reactions, the amino acids display color at different levels of intensity. Therefore, the reaction is based upon a “standard amino acid”; glycine usually serves as the standard amino acid for comparison.
With the ninhydrin method, the color yield varies with the individual amino acids between 70 and 105 %, based on glycine. Up to approx. 30 % of ammonium salts are quantified using this method and up to approx. 7 % of proline.