Koizumishuzou Co., Ltd. in Yawatahama, Ehime Prefecture, produced Koinose, a brand whose name invokes the vigor of a carp climbing a waterfall, using Gohyakumangoku rice and Ehime-developed EK-1 yeast under the guidance of experienced Igata-school toji. The brewery was known for low-temperature fermentation and meticulous attention to raw materials, yielding a powerful sake with a strong presence. Koizumishuzou has since ceased operations, making Koinose a closed chapter in Ehime sake history.
