Wheat malt intended for use in the production of beer
This method describes how to determine the electrical conductivity of water using a conductivity meter.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The electrical conductivity of a water sample is regarded as a sum parameter of all of the ions dissolved in the water sample. The electrical conductivity is determined by the ion concentration and the types of ions as well as the temperature and the viscosity of the solution. Due to dissociation of the water molecules themselves, water containing no dissolved extraneous ions possesses an extremely low electrical conductivity of ≤1 µS/cm-1. Drinking water often exhibits conductivity between 100 and 1000 µS/cm-1 (limit threshold according to the Trinkwasserverordnung – TrinkwV (the regulations governing drinking water in Germany): 2500 µS/cm-1 at 25 °C). By comparison, rainwater exhibits a value for electrical conductivity between 30 and 60 µS/cm-1, while that of sea water is commonly 42,000 µS/cm-1.
Determination of the dissolved nitrogen (N2) content using heat conductivity in carbonated and non-carbonated beverages that have been nitrogenated
This analysis is suitable for determining the concentration of dissolved nitrogen (N2) in carbonated and non-carbonated beverages that have been nitrogenated.
Dissolved nitrogen in a liquid medium is measured using the same procedure as the CO2 determination, i.e., using heat conductivity.
CO2 is employed as a purge gas in the beverage industry. Therefore, in order to measure nitrogen, the change in thermal activity and CO2 and N2 is used. The thermal conductivity is determined in a small measurement chamber, which in turn is separated from the material being measured by a semipermeable membrane. Diffusion through the membrane changes the thermal conductivity in the measurement chamber.
The gas volume in the measurement chamber is fully replaced in cycles of 10–20 s. The changes in thermal conductivity over time are a measure of the diffusion of N2 through the membrane, which allows the concentration in the medium to be calculated, taking temperature into account.
The calculation for the concentration of N2 is achieved using the change in thermal conductivity in the measurement chamber, also taking the temperature into account.
Since the thermal conductivity of oxygen is similar to that of nitrogen, a second channel may need to be used to compensate for any oxygen in the medium [1].
This method describes how to determine the mycological status of a lot of barley as part of visual and manual inspections.
Kernels with a visually recognizable fungal infection is distinguished primarily by a black but at times pinkish red (barley) or white (wheat) discoloration over part or all of its surface. Pinkish red or white kernels indicate an infection by a species of Fusarium.
This method describes how to determine whether a lot of barley or wheat is contaminated with Fusarium graminearum using mannitol agar.
Fusarium graminearum contamination in barley or wheat can be visually determined with the naked eye after three to five days of incubation on mannitol agar.
Fusarium culmorum contamination in barley or wheat can be visually determined with the naked eye after three to five days of incubation on mannitol agar to which malachite green has been added.