Sake and Shochu, do you know them?

As craft spirits continue to thrive, the ancient Japanese spirit, Shochu, is gaining growing interest among Europeans and Americans. But what exactly is Shochu? Modern Shochu can be divided into two legally defined categories:

• Shochu distilled continuously to a high alcohol degree. Generally, it lacks the distinct characteristics of the raw material and is consumed locally, sold at a low price.
• Shochu distilled to a relatively lower alcohol degree using pot stills, which retains the distinct aromas and textures of the raw material. This category includes Honkaku Shochu and Awamori.

Shochu production and raw materials

Various starch-based ingredients such as sweet potatoes and grains (rice, barley, wheat, or buckwheat) are used to produce Shochu. The choice of raw material is closely tied to the region and local traditions. The production process of Shochu begins with the preparation of the raw material. When the base is a grain, it is first polished to remove the bran (the first layer after the husk), leaving around 75-80% of the grain. The outer part mainly contains sulfur compounds that would produce unpleasant aromas if fermented. The grain is then washed to remove dust and generally steamed. The cooking process softens the starches, making them soluble for saccharification. For a sweet potato base, the potatoes are simply cut into small cubes before being steamed as well.

The KOJI Stage

The next stage is to create the substance that will convert the starches into sugars (the saccharification process). This is necessary because starch is a long molecule that yeast cannot process. Instead of using the cereal’s own enzymes, released during malting in whisky production, Shochu uses a mold called Koji. Spores are spread over the cooked raw material, developing under warm and humid conditions, releasing enzymes that convert the starch into fermentable sugars. The process takes two to three days. There are different types of Kojis: the main ones are Yellow Koji, mostly used in sake production, and Black and White Kojis used for Shochu production. The latter two are used as they release several beneficial substances, such as ascorbic acid.

The FIRST MASH

The fermentation process is divided into two stages called Shikomi. The goal of the first Shikomi is to cultivate yeast in a small amount with about one part water and one part Koji, allowing for rapid multiplication. Koji also produces acid; in sufficient concentration, it helps protect the batch from contamination. A batch without intermediate steps would dilute the acid, slow down yeast multiplication, and risk contamination by unwanted yeasts or bacteria. This process typically takes five to six days. The first Shikomi accounts for between one-fifth to one-third of the final volume. The final product of the first Shikomi is called the first Moromi (fermentable mash).

The SECOND MASH or second Shikomi

During the second brewing (second Shikomi), the main ingredient (rice, barley, or sweet potatoes) is mixed with water and then added to the first Shikomi. The main ingredient determines the style and legal category of Shochu. Fermentation lasts one to two weeks depending on the ingredient used. The alcohol content will reach about 14-20%. After this stage, the mash is transferred to the pot still for distillation.

Shochu DISTILLATION

By law, Honkaku Shochu or Awamori must be distilled only once in a pot still. Distillers use two different techniques: atmospheric distillation and vacuum distillation. In atmospheric distillation, the temperature of the Moromi (fermented mash) rises to approximately 85-95°C. This heating creates rather rich aromas. On the other hand, with vacuum distillation, the pressure inside the still is reduced, allowing the Moromi to be distilled at 45-55°C. This method produces lighter distillates with a more subtle style. Many distilleries use a combination of both methods to create complexity.

Shochu AGING

Most Shochu is aged in pottery for a few months to allow additional reactions between different aromatic compounds. Lighter styles may be released on the market after just a few weeks in stainless steel tanks, which do not add complexity.

Discover emerging trends in the world of spirits and their styles

SHOCHU STYLES

• Sweet potato (Imo Shochu): Shochu made from sweet potato as a base, typically using rice Koji. Most Shochu is made in Kagoshima prefecture, but Miyazaki prefecture also produces large volumes.
• Satsuma Shochu: Geographical Indication for Shochu made from sweet potatoes in Kagoshima prefecture, excluding the Amami Islands.
• Barley (Mugi Shochu): Shochu made from barley as a base, usually using rice Koji. The largest producers are concentrated in Oita and Miyazaki.
• Iki Shochu: Geographical Indication for barley Shochu made on Iki Island. Koji must be made from rice.
• Rice (Kome Shochu): Shochu made entirely from rice (rice Koji and a rice base). Kumamoto prefecture is the major production region.
• Kuma Shochu: Geographical Indication for the Kuma district in Kumamoto prefecture.
• Sake-Kasu Shochu: Shochu made from sake lees. Water is traditionally added to the sake lees to restart a second fermentation, thanks to the remaining sugars and yeast from sake production. Generally made in sake-producing regions such as Saga and Fukuoka.
• Awamori: Shochu produced from long-grain rice from Thailand, unlike the round rice traditionally used in Japan. It differs from Honkaku Shochu due to its unique Shikomi process, where all the rice is converted into Koji and added at once in the fermentation tank instead of the traditional two-stage Shikomi process. This method is made possible by using black Koji, which produces different enzymes and substances that protect the mash.
• Ryūkyū Awamori: Geographical Indication for Awamori produced in Okinawa prefecture.
• Brown sugar (Kokutō Shochu): Made from rice Koji and diluted brown sugar as the base for the second Shikomi.

Other ingredients

The Japanese National Tax Agency allows a list of about 40 ingredients to flavor Shochu (using Shiso leaves, sesame seeds, seaweed, teas, buckwheat, etc.).

The world of spirits is a wonderful one. Are you eager to discover this world and the art of mixology? Train for the spirits sector careers with WiSP!