2.2.4. Activated starter
Activated starter was prepared by mixing 1 kg A. kawachii
starter, 12.5 g SAF-Instant yeast and 1500 mL sucrose water solution
of 15 g/1000 mL in a container, and incubated at 25 C for 30 h
under aerobic condition.
2.3. Fermentation process for original fermented mashes
One kilogram rice was rinsed 3 times to remove the impurities,
followed by soaking in water (w25 C) for 2 h until saturation of
water adsorption. Excessive water was removed, and the soaked
rice was then steamed for around 40 min to allow the full gelatinization
of rice. The steamed rice was cooled down from more
than 95 C to less than 30 C within 10 min in an air blast cooler
(YW-30, Yaegaki Co., Japan), then the steamed rice was transferred
to a 5 L plastic fermentation container. 2 L water, 20 g modified
starter, and 200 g activated starter were added into the container
and incubated at 22 C until the completion of the fermentation,
which took 7 days. At the end of fermentation, the whole mash
was mixed and filtered, the coarse filtrate was used as original
fermented mash (OFM). In the whole process of turbid rice wine
preparation, no food additives were allowed to be added, so as to
investigate the effects of different rice cultivars on the quality of
turbid rice wine. Triplicate fermentations for each rice cultivar
were carried out.
2.4