Determination of the cold wort yield in order to monitor brewhouse operations
Wort from the midpoint of chilling/pitching wort
Instead of brewhouse yield, quite often the cold wort yield is calculated. Cold wort yield is particularly recommended for wort produced using adjuncts. Extract yield is understood as the amount of extract in a batch of wort relative to the amount of extract in the raw materials used to produce the wort.
Determination of the amount of cold break material in the pitching wort
Cast-out wort, wort from the midpoint of chilling/pitching wort (without yeast)
The hot break material (trub) and any hop particles which may be present in the wort, must first be removed. After the wort has been cooled to 2 °C, it is filtered through a glass fiber filter. The residue remaining on the filter is dried and then weighed.
Cold break material or cold trub refers to all material that settles out in the process of chilling wort after separation of the hot trub or hot break material. Cold trub can be filtered out of the wort and primarily consists of proteins (48–57 %), tannins (11–26 %) and carbohydrates (20–36 %). The amount of cold break material in wort depends on the quality and composition of the raw materials, brewhouse equipment and wort handling. In academic and professional circles, opinions regarding the significance of cold break material for downstream processes and for the quality of the finished beer are strongly divided [1, 2, 5]. Under certain circumstances, the quantity of cold break material in wort may exceed 250 mg/l, especially where accelerated fermentation is practiced. Ultimately, this can detract from the flavor of the finished beer [3]. Breweries, where removal of the cold break material has been practiced successfully, determine the quantity of cold break in their pitching wort at regular intervals, in order to evaluate the efficacy of their separation equipment.
Determination of the overall brewhouse yield during wort production in order to monitor brewhouse operations
Wort from the midpoint of chilling/pitching wort
Since determination of the hot wort yield can be problematic and the cold wort yield as described above does not represent a measure of the total extract obtained from the grain bill, an attempt has been made to record all of the extract recovered, with the exception of that remaining in the spent grain. This value is then compared to the laboratory yield. The result is expressed as the total yield (overall brewhouse yield) (OBYCW) in %.
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.
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.