This method describes how to determine the capacity for water imbibition (moisture uptake) in barley.
Barley intended for the production of malt is evaluated on the basis of its capacity for water imbibition.
Barley is steeped according to a defined scheme, and the absorption of the steeping liquor by the kernels at defined times is determined by calculating the moisture content. The moisture content after 72 h steeping time is used to assess the absorption of steeping liquor or the capacity for water imbibition in barley.
Potassium permanganate oxidizes many organic and certain inorganic substances more or less completely in acidic, neutral or alkaline solutions. The volume of potassium permanganate required in the analysis is determined potentiometrically. Since oxidation depends on the type of solution, on its temperature and on the reaction time, the procedure described below must be followed precisely.
In acidic solutions, permanganate ions are typically reduced to manganese(II) ions:
MnO4- + 5 e- + 8 H3O+ → Mn2+ + 12 H2O
In alkaline solutions, the reduction results in tetravalent manganese only:
MnO4- + 3 e- + 4 H3O+ → MnO2 + 6 H2O
Since in both cases the titration takes place in an acidic solution, this is irrelevant for the calculation. By adding oxalic acid, both the excess permanganate ions as well as the tetravalent manganese are reduced to manganese(II) ions:
2 MnO4- + 5 C2O42- + 16 H3O+ → 2 Mn2+ + 24 H2O + 10 CO2
MnO2 + C2O42- + 4 H3O+ → Mn2+ + 6 H2O + 2 CO2
Boiler water for use in the production of beer and other foods
Analogous to the p and m values obtained in the determination of acid capacity (pH 8.2 and 4.3), this analysis is performed according to W-000.13.031 Acid Consumption (Alkalinity, p-Value and m-Value)/Acid Capacity to pH of 8.2 and/or 4.3 for Water. The alkaline capacity of the boiler water is determined through titration of the sample with 0.1 N sodium hydroxide (instead of hydrochloric acid) to a pH of 4.3 and/or 8.2.
Whole hops intended for use in beer brewing or elsewhere in the food industry
Evaluation of the appearance of hop cones is performed through visual inspection and sensory assessment.
As is the case with drinking water, water employed for the production of beer and soft drinks must be neutral in odor and taste.
beer, beer-based beverages, non-alcoholic beverages, mineral water
A qualitative test is performed after shaking the water in a sealed, odor-neutral bottle. Water possessing an odor is measured quantitatively on the basis of a sensory threshold. Water possessing an odor is diluted with odorless water until the odor is barely perceptible (by at least three people). The ratio of the total volume (water with odor + odorless water) to the volume of the mixture containing the water sample is designated as the odor threshold. The taste test should always be performed after evaluating the odor, since the perception of odor can be influenced by flavor.
This method describes how to determine the acid consumption or acid capacity of water.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods