Discovering Shochu: Episode 12 – The Differences between Honkaku Shochu & Korui Shochu

According to the Liquor Tax Act in Japan, Shochu is defined by the distillation method. Honkaku Shochu refers to Shochu that’s distilled once using a single distillation machine and with an alcohol percentage of 45% or less.

Korui Shochu refers to shochu distilled using a multiple distillation machine and with alcohol percentage of up to 36%.

Single distillation machine (Pot Steel): There are 2 types of single distillation methods, Atmospheric Distillation & Vacuum Distillation.

Atmospheric distillation is the traditional distillation method. Shochu is distilled under normal atmospheric pressure (about 176-194 degrees F). It is the best method to bring out the aroma of the ingredient and highly suited for aging. (Fig.1) Reference: Boiling point of water is 212 degrees F.

Vacuum Distillation lowers the pressure inside the distillation machine and distills the shochu at about 104-140 degrees F. This reduces the unpleasant steamy aroma and instead brings out the light and refreshing aroma of shochu. (Fig.2)

Multiple Distillation machine (Patent Steel): There are dozens of shelves inside the distillation machine used to make Kourui Shochu. Moromi mash is added in the middle shelves, and as the liquid pours down to the lower level, the steam vaporizes the liquid which then gets cooled and turns into Shochu.

Shochu made with this method loses most components of the ingredient except alcohol (ethanol). It produces color-less Shochu with a clear and refreshing taste.

Multiple distillation doesn’t refer to the process of distilling multiple times but rather adding the moromi mash ingredient successively to the distillation machine. (Fig.3)

Requirements of Shochu:  In order for distilled liquor to be called shochu, it must meet several criteria:

1) Ingredient must not contain:

• Fermented grains (malt): to distinguish from Whiskey
• Fruits (except date palm):  to distinguish from Brandy
• Saccharine substance* (sugar, honey, maple syrup): to distinguish from Rum*Exception: Kokuto (brown sugar) Shochu distilled in Amami Island, Kagoshima Prefecture is permitted.

2) Moromi mash and Genshu must not:

• Undergo ash (carbon) filtration: to distinguish from Vodka
• Include Juniper berries: to distinguish from Gin

3) Absorbance or optical density: Through aging, shochu takes on an amber color. To differentiate from Whiskey, the color must not be too dark (spectrometer must be less than 0.08). If Shochu is too dark, it must be adjusted by blending aged shochu with lighter colored shochu.

4) Added Sugar: The addition of sugar is permitted but the amount of sugar must be under 2% and it must be clearly indicated on the Shochu label.  Shochu with added sugar can be classified as Single Distilled Shochu but not as Honkaku Shochu. Note: Kokuto (brown sugar) Shochu is considered Honkaku Shochu because no sugar is added to the ingredient.