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The quantity of soluble dry matter is determined refractometrically. This is related to the percent by weight of sucrose in an aqueous sucrose solution, which under defined conditions possesses the same refraction index as that of the product being analyzed. The amount of soluble dry matter is expressed in g per 100 g of solution. The refraction index is not determined directly for non-alcoholic soft drinks, but rather by means of a scale based on the percentage of sucrose by weight (°Brix). Since the °Brix scale uses sucrose, correction factors for other sugars must be taken from tables for each individual type of sugar. The presence of other substances, such as organic acids, minerals and amino acids, has an effect on the refraction index of a product. Due to the high acidity of citrus juices and citrus juice concentrates, correction factors are also necessary for measuring their °Brix values.

Titratable acidity represents the sum of the free acids present in a beverage, with the exception of the dissolved carbon dioxide (carbonic acid). In fruit juices and the beverages prepared from them, they usually consist of malic acid, citric acid and tartaric acid.

The titration of the degassed beverage sample (freed from carbonic acid) is carried out potentiometrically using 0.25 mol/l sodium hydroxide solution either to a pH of 7.0 calculated as tartaric acid or to a pH of 8.1 calculated as citric acid.

Volatile acids are distilled using steam, and the distillate is analyzed through titration. Sulfurous acid present in the distillate is determined iodometrically and subtracted from the total.

The pH value influences the enzymatic degradation processes during mashing and determines the solubility of the proteins, the hop bitters and the coloration during wort boiling. Furthermore, there is a dependence between the pH of the wort and that of the beer prepared from it. Beers with high pH values are more susceptible to chemical-physical turbidity due to inadequate protein coagulation in the brewhouse. Measuring the pH of wort and beer is therefore part of routine quality control.

The pH value is determined electrometrically [1-4].

Determination of pH is always done in the same way for wort, beer, beer-based beverages, NAB, juices and beverages.

Carbonated beverages must be decarbonated before measurement.

The amount of time required for a special ball to fall while sinking through a glass tube filled with a sample liquid between two marks is measured. The precision of this method is increased if the time is measured using a photoelectric beam to an accuracy of 0.01 s, rather than manually with a stopwatch.

Capillary viscometers measure the kinematic viscosity of Newtonian fluids, unlike falling ball and the rotational viscometers, which directly measure the dynamic viscosity. However, with values for the kinematic viscosity and the density of the test liquid, the dynamic viscosity can be calculated.

The time required for a volumetrically defined amount of fluid (the volume between two marks on the tube of the viscometer) to flow through a capillary of a defined length is measured.

1 square meter per second of a homogenous fluid with a dynamic viscosity of 1 Pa × s and a density 1 kg/m³

The unit for expressing kinematic viscosity (the relationship of viscosity to density = viscoplasticity) is 1 m²/s = 10⁶ mm²/s

The kinematic viscosity is expressed as 1 square meter per second of a homogenous fluid with a dynamic viscosity of 1 Pa × s and a density 1 kg/m³.