Changes of wort characteristic components through low thermal stress boiling

This paper systematically studied the changes of wort characteristic components under various low thermal stress boiling, and separation methods of Dimethyl-Sulfide (DMS) accumulated in wort due to low thermal stress boiling. Compared with conventional boiling, the combined boiling (boiling at 3% evaporation rate and 98 degrees C holding temperature for 30 min) demonstrated that the change rates of solidifiable nitrogen, iso-alpha-acid and color were no more than 5%, the absorbance of thiobarbituric acid (TBA) reaction mixture decreased by 13.7%, and DMS can be separated by vacuum film stripping after whirlpool. For 98 degrees C holding temperature boiling, the differences in absorbance of TBA reaction mixture, iso-alpha-acid and color were 16, 11.6 and 5%, respectively. The solidifiable nitrogen content was equivalent to the 28 mg/L limit and DMS must be removed by vacuum film stripping two times. From the perspective of application, it is necessary to improve the separation efficiency of DMS subsequently.