P-19 - Investigation of Brewing Parameters for Improving Wheat Beer Filterability

In Japan, barley malt beer and wheat beer are commonly clarified by filtration. However, wheat beer often presents filtration challenges. This issue is particularly sensitive in large-scale breweries, as poor filterability may reduce productivity. From the above, the improvement of wheat beer filterability processes is highly desirable. Therefore, this study aimed to determine the main factors affecting the filterability of wheat beer. We hypothesized several factors with the potential to improve wheat beer filterability: wort boiling time, hop dosage, addition timing, yeast type, and addition rate. To evaluate these parameters, eight beers were brewed on a 100-L pilot-scale apparatus. These beers were subjected to originally developed microscale filtration system. The eight beers were labeled as No.1-1, No.1-2, No.1-3, No.2, No.3, No.4-1, No.4-2, and No.4-3, respectively. No.1-1 was a top-fermented beer brewed with 60% wheat malt employed as our control sample for poor filterability. Beers No.1-2 and No.1-3 were brewed with double and triple yeast rates compared to the control. Beer No.2 was boiled for 180 min, twice the boiling time of the control. Beer No.3 was brewed by eliminating late hopping from No.2, using only kettle hopping, with double amounts of kettle hops. Beers No.4-1, No.4-2, and No.4-3 were bottom-fermented beers brewed under the same conditions as No.1-1, No.1-2, and No.1-3, respectively. Our results showed that the filterability of beer No. 3 was significantly improved by the extension of the boiling time and increased amount of kettle hops. The improved filterability under these conditions is attributed to the promotion of hot-break formation during the wort boiling process. Furthermore, the filterability of beers No.4-2 and No.4-3 was also improved using double and triple bottom-fermenting yeast rates compared to top-fermenting yeast. From these results, we can conclude that the filterability of wheat beer can be improved by changing the wort boiling time, the amount of kettle hops added, the type of yeast added, and the yeast addition rate. These results provide interesting possibilities for improved filtration processes and the overall productivity of large breweries.