Japan: New invention permits to quickly measure the factor causing the early flocculation of yeast in brewing materials

A new invention patent was assigned to Kirin Beer Kabushiki Kaisha for providing a method for quickly measuring factors causing early flocculation of yeast contained in brewing materials, and a method for quickly determining early flocculating property of yeast by using the measuring method, European Patents released October 24.

Yeast at late logarithmic growth phase or thereafter is prepared, and the yeast is mixed, suspended with water-extracted high-molecular weight fraction of test material sample from oat or malt in a buffer solution, and by measuring the precipitation level of the mixed and suspended yeast, it is possible to measure factors causing early flocculation of yeast contained in brewing materials without performing a fermentation process as in conventional method, in a quite short time period, with a minute amount of sample.

The water-extracted high-molecular weight fraction of the test material sample can be easily prepared by extracting brewing materials with water, and then by using ethanol precipitation, or dialysis, ultrafiltration, gel filtration, and the like. Further, precipitation level of yeast can be measured accurately with an easy and simple means such as a measuring method using optical density by using OD600.