Malt intended for use in beer brewing or elsewhere in the food industry
Determination of the "air volume" (gas volume other than carbon dioxide) in the headspace of bottles and cans
Suitable for determination in beer, mixed beer beverages and carbonated beverages
The method provides valuable information on effective and uniform foaming and undercap gassing during can filling.
The gas in the headspace of bottles and cans is captured under a funnel filled with water and subsequently migrates very slowly through a column of liquid containing potassium hydroxide or sodium hydroxide, whereupon the carbon dioxide also contained in the headspace is bound by the caustic solution. The remaining gas, consisting of nitrogen and oxygen, is captured in a burette, from which the volume can be read. The value from the burette is expressed as “air in headspace” [1].
Determination of dissolved oxygen concentration using electrochemical oxygen sensors with an optochemical sensor
The basis for these O2 measurements is the detection of photoluminescence produced by an oxygen-sensitive layer. The change in photoluminescence depends on the partial pressure of the oxygen. Given the values for the partial pressure of the oxygen and the temperature, the amount of oxygen gas dissolved in the liquid can be calculated. The oxygen sensor determines the O2 content of the liquid by means of optical detection through a photoluminescent process, in which an oxygen-sensitive layer is exposed to blue light. In doing so, the molecules in this layer become excited and reach a higher energy state. In the absence of oxygen, the molecules emit a red-colored light. If oxygen is present, it collides with the molecules in the oxygen-sensitive layer. The molecules in the oxygen-sensitive layer, which have collided with oxygen, cease to emit light (refer to figure 1). For this reason, a relationship exists between the oxygen concentration and the intensity of the emitted light as well as the intensity and the rapidity with which the intensity of the light diminishes. The intensity of the light is reduced at higher oxygen concentrations, although the rate at which it does so increases. The temperature of the product and the time interval between the light signal and the emission of light (phase shift) are both measured and used to calculate the oxygen content.
The device’s construction enables the state of the blue LED to be monitored using a photodiode. Another photodiode – with a red filter – measures the oxygen-dependent red light (refer to figure 2). This light is emitted by the luminophores due to photoluminescence (fluorescence) after they reach an excited state through exposure to the blue light. As a result of this exposure, the electrons of the luminophores are elevated to a higher energy level. As they return to their original energy level, they emit a red light.
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.
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
This method describes how to determine whether a lot of grain is contaminated with ergot visually through manual inspection.
Barley intended for the production of malt; therefore, the kernels are to be evaluated on the basis of the characteristics described below.
A representative sample of grain is visually inspected for the presence of ergot sclerotia.