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.
This method describes how to determine the quantity of lime water necessary for softening water used in brewing (brewing liquor) and food production.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Through the addition of lime water or 'milk of lime,' the hydrogen carbonates and free carbon dioxide are transformed into carbonates and are then largely precipitated:
Ca(HCO3)2 + Ca(OH)2 → 2 CaCO3 + 2 H2O
Mg(HCO3)2 + Ca(OH)2 → MgCO3 + CaCO3 + 2 H2O
CO2 + Ca(OH)2 → CaCO3 + H2O
Calcium carbonate is insoluble and precipitates out. By contrast, magnesium carbonate is to a large extent soluble in water. The addition of one more equivalent weight of Ca(OH)2 transforms magnesium carbonate into insoluble magnesium hydroxide:
MgCO3 + Ca(OH)2 → CaCO3 + Mg(OH)2
However, the amount calculated for this form of water treatment would lead to a surplus of lime in the water (and a higher than desired pH), since an especially high alkalinity is required for the quantitative precipitation of magnesium hydroxide. Therefore, the “split treatment” method, as it is known, is preferred, i.e., the quantity of lime water calculated for the total quantity is added to ⅔ of the untreated water. An excess of lime results, and therefore, the magnesium hydrogen carbonate is also precipitated. The addition of approx. ⅓ of the untreated water diminishes the lime surplus and causes the complete precipitation of calcium hydrogen carbonate. By doing so, the hardness caused by calcium carbonate is entirely eliminated, and the hardness caused by magnesium carbonate is to a large extent as well.
The method describes how to determine the residual alkalinity in the water used as an ingredient in beer production (brewing liquor).
The residual alkalinity is calculated using the following parameters: total hardness, calcium hardness and magnesium hardness.
Water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
The level of carbonate removal in the water treatment system is monitored using the analysis for the p and m values. The standard values specified in the analysis should not be exceeded.
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.
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.