Changes in malt wort dynamic viscosity during fermentation

Abstract

Physical properties particularly mechanical, rheologic, electric and thermophysical properties are important to know at quality valuation of food materials. Rheologic properties were measured by many authors and for many materials. Results from measuring of rheologic properties of malt wort are shown in this paper. Measuring was performed by digital rotational viscosimeter Anton Paar (DV-3P). First sample of malt wort was taken at the beginning of fermentation and second sample was taken after 3 hours of fermentation. Samples of malt wort were stored at temperature 3 °C and were measured in different days. Measurements were done after the temperature stabilization from 7 °C to laboratory temperature. Dependencies of dynamic viscosity on temperature and on time of fermentation are described. Temperature dependencies of malt wort viscosity are decreasing exponentially. Longer fermented sample had lower values of viscosity in all measurements. Measured values of dynamic viscosity were obtained with good precision and all drawn dependencies had very high coefficients of determination.

Keywords

• malt wort
• dynamic viscosity
• temperature
• storing time
• time of fermentation