Malt intended for use in beer brewing or elsewhere in the food industry
The value of pH is defined as the negative decadal logarithm of the concentration of hydrogen, or more precisely, hydronium ions:
\(\text{ pH }=-\log{ c_{ H_{ 3 }O^{ + } } }\)
The pH scale, ranging from 0–14, is based on the dissociation equilibrium.
The pH value of a liquid is commonly determined with a pH measurement device consisting of the measurement electrode (glass) and the reference electrode (e.g., silver/silver chloride electrode), which is connected to a signal amplifier and a display instrument. The device is calibrated using standard buffer solutions.
The pH reading displayed is determined through the difference in electrical potential between the reference solution in the electrode and the solution being measured.
Generally, a pH measurement system is used, in which the measurement and reference electrodes are combined to form a single unit.
Determination of the total oxygen content (dissolved and in the headspace) in filled containers
The bottled or canned beer is brought to 20 °C and mechanically shaken, thereby achieving equilibrium between the oxygen dissolved in the beer and the oxygen present in the headspace (Henry’s and Dalton’s laws). By directly measuring either the oxygen in the beer or in the headspace, the total oxygen can be calculated through referencing a table of values, which includes the headspace volume as a percentage of the fill volume.
Determination of the fermentation cellar yield in order to monitor brewhouse operations
Wort from the midpoint of chilling/pitching wort
The fermentation cellar yield is calculated using the value determined for the amount of extract contained in a batch of wort relative to the amount of extract present in the raw materials used to produce the wort.
The gelatinization temperature can be determined using a rotary viscometer (e.g., Amylograph or Viscograph, Brabender GmbH & Co. KG, Germany [4] or a Rapid-Visco-Analyser, RVA, Perten Instruments, a PerkinElmer Company, USA [8]).
A suspension consisting of a finely ground sample and water is produced, whose precise mixing ratio should correspond to the analysis protocol for the adjunct in question. However, since for many cereals and pseudocereals no official analysis protocol exists, the initial weight for the adjuncts listed in table 2 has been determined empirically [3].
Once the suspension is prepared it is attempered according to a pre-programmed temperature/time program, and the viscosity is determined on a continuous basis by means of a rotor and a rotary torque measurement (fig. 1). When gelatinization begins, an increase in the viscosity is registered, and the corresponding sample temperature is defined as the gelatinization temperature. The standard evaluation criterion (PT) is a viscosity increase of at least 24 cP (≙ mPas) within six seconds.
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
visual assessment
This method describes how to determine whether kernels are cracked as part of the visual and manual inspection of a lot of barley.
Barley intended for the production of malt is to be evaluated on the basis of the characteristics described below.
Visual assessment