Evaluations of properties and flavors of beer with local fruits as auxiliary ingredients

Abstract

The Liquor Tax Law in Japan was revised in 2018, and the revision has significantly deregulated both the variety and the quantity of the auxiliary ingredients permitted for use in beer. Consequently, we prepared worts containing three citrus fruits (Kara, Miekinan4gou, and Summer fresh), passion fruit, and atemoya that were local fruits in Mie Prefecture, and brewed beers by fermenting the worts with top-fermenting yeast or bottomfermenting yeast. By the fourth day from the beginning of fermentation, various sugars included in the worts, such as glucose, fructose, maltose, and maltotriose, were substantially decreased, and had been utilized for ethanol fermentation. The flavors of the fruits, especially organic acid and the volatile terpenes, remained in the beers. Microorganisms were detected in the juices of the passion fruit and atemoya, but were not detected in the beers in which these fruit juices were employed as auxiliary ingredients. The antibacterial action of the alcohol and hop likely had a sterilization effect. The results of sensory evaluations indicated that, although the fruit flavors remained in the beer, the conditions of fruit addition need to be optimized.