Search: turbidity

The formation of haze is forced through the addition of formaldehyde and storage at 0 °C. The difference in the turbidity formed and the turbidity at the beginning is compared.

A water sample containing undissolved substances diminishes the incident light radiation and scatters it unevenly in all directions. The intensity of the scattered radiation depends on the wavelength of the incident light, on the measurement angle and on the form and size of the suspended particles. The results of the turbidimetric analysis are related to a “standard formazin turbidity”.

Strong supercooling causes reversible turbidity in beer, which depends on the condition of the beer and is caused by precipitated polyphenol-protein complexes. The addition of alcohol reduces the solubility of the complexes and thus accelerates the formation of turbidity.

The cold test, which can be performed very quickly, allows predictions to be made about the expected permanent turbidity of the beer. Immediately after filtration or bottling, the AKT provides indications of the turbidity potential of a beer and the effectiveness of stabilization measures, which can then be evaluated and modified if necessary.

The influence of oxygen is not recorded by the test.

Beer is cooled strongly (to -8 °C) in a cuvette with the addition of alcohol (up to 6 %) (down to -8 °C). The turbidity formed in a specified time (40 min) is measured (EBC formazin units).

If a beam of light strikes a particle with a diameter larger than the wavelength of the light, the light is scattered. In measuring turbidity during the lautering process, it has been shown that only light scattered in a forward direction should be measured to achieve a meaningful correlation between the concentration of solids and the measurement value. Measurements performed at a 90° angle do not correlate with the amount of solids in wort due to particle size and dependence on color. Measurements performed at a 12° angle not only measure the amount of scattered light, but also the absorption (light transmission). The utilization of dual light beams eliminates disruptive factors, such as color, the age of the lamp and window fouling.

Measuring the turbidity during lautering serves to monitor and control lauter bed cutting operations and recirculation of the turbid wort as well as the quality of milling and mashing processes. There is a direct relationship between the turbidity profile during lautering, the results of the photometric iodine test and the solids content of the lauter wort.

The degree of turbidity present in a beer sample can be compared to a clear beer of the same brand and style to which EBC formazin standard solution has been added to produce haze in the beer. The degree of turbidity can be determined through visual comparison of the two beers.

If a beam of light strikes a particle in a liquid, the light is scattered. This phenomenon is referred to as turbidity. In measuring turbidity during the lautering process, it has been shown that only light scattered in a forward direction should be measured to achieve a meaningful correlation between the concentration of solids and the measurement value. Measurements performed at a 90° angle do not correlate with the amount of solids in wort due to particle size and dependence on color. In addition to the amount of scattered light, the absorption (light transmission) is also measured. The utilization of dual beams eliminates disruptive parameters such as color, lamp age and window fouling.

For monitoring filter efficacy, measurements employing forward scattered light are advantageous (measured at an angle ranging from 11 to 25°).

With a suitable turbidity measuring device, the visual impression of turbidity is quantified.