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.
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.
Hop extract intended for use in beer brewing or elsewhere in the food industry
SO2 in the Karl Fischer solution creates an ester with methanol, which is neutralized through a reaction with a base. The anions of methylated sulfuric acid are the reactive component in the chemical reaction. In the water titration, the methyl sulfite anions are oxidized by iodine to form methyl sulfate. The endpoint can be determined either by a color change (addition of a starch solution) or electrochemically.
This method describes how to determine the true color of water by means of spectrophotometry.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The color of water is determined by measuring the absorbance at a minimum of three wavelengths at various points across the visual spectrum:
λ1 = 436 nm (obligatory), λ2 = 525 nm, λ3 = 620 nm (for λ2, λ3 minor deviations are permitted). If necessary, measurements at additional wavelengths must be carried out.
This method describes how to determine the color of water by visual means.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
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.