After sake (nihonshu), shochu is the second traditional drink of Japan.

Shochu is a destillate that was originally produced in Japan, contains about 25% alcohol by volume and was first produced on the island of Kyushu in the south of Japan.

Shochu is normally divided into two categories: the singly distilled premium brands such as Honkaku shochu or Awamori and multiply distilled mass-produced products such as Korui shochu. Here at shizuku, the expression shochu always refers to the singly distilled premium brands.

Honkaku shochu and Awamori are spirits that are produced in a process called pot still distillation. The majority of this destillate contains about 25 per cent alcohol by volume, some up to 45 per cent alcohol by volume. In Japan, this is the upper limit regulated by law. Honkaku shochu and Awamori are therefore stronger than wine or sake but are mostly weaker than whisky or other spirits known in Europe or the US.

Honkaku shochu has been produced in Japan since the sixteenth century. Machines for distillation were imported to the Ryukyu chain of islands from Indo-china and then sent to Satsuma – the western part of the present-day Kagoshima Prefecture on Kyushu. This is one of the reasons why Kyushu is the home of shochu. Depending on the area, shochu are produced on the island of Kyushu with different regional main ingredients.

Awamori, which was originally produced on the Ryukyu islands (Okinawa), has also been brewed in Japan since the fifteenth century. Only long-grained Thai rice and black koji are used in its production. With 30 to 43 per cent alcohol by volume, it is higher than that of Honkaku shochu.

Honkaku shochu is brewed from the following main ingredients: barley, rice, sweet potato, sugar cane, sesame or buckwheat. It is clear from such different ingredients alone how broad the bouquet variety of shochu is.

Shochu is a multifaceted drink, which can be enjoyed in different ways depending on the season and your personal taste (drinking experience). Shochu is also a great accompaniment to meals.

Base ingredients - barley, sweet potato, rice etc.
Depending on the variety, the main component is added in the production process once the second mash has received the relevant treatment. It is this mash that gives the alcohol the base for its bouquet.

If you want to know more about the main ingredients, you can read more about this subject in the section on shochu varieties.

Water
No alcoholic drink can be produced without water. The same also goes for shochu, which contains up to 70 to 80% water. In Japan, natural water is usually soft and therefore low in minerals - something that is preferential for the production of shochu. Using soft water can bring out a distinct bouquet and also intensify the flavour of the main ingredients.

Koji
Koji are Aspergillus oryzae fungi. In the shochu production process, it is usually rice - less frequently, barley - that is inoculated with koji. This creates enzymes, which break down the starch in the steamed rice and as a result, dextrose, which is essential for the fermentation process, can be produced. In the section on shochu production, shizuku explains which varieties of koji are used to produce shochu and to what extent the choice of koji affects the flavour of the final product.

Washing, soaking and steaming rice
As in the production of sake (nihonshu), koji-rice, which is rice fermented with yeast, is made by first washing the rice, soaking it and then steaming it.

Making rice-koji
The steamed rice is then inoculated with koji (Arpergillus oryzae mould). The enzymes that are created in this process break down the starch in the steamed rice and as a result, dextrose (glucose), which is essential for the fermentation process, can be produced.

It normally takes between 36 and 48 hours to produce rice-koji. It is only at this point that the rice-koji has attained the desired balance of flavour, temperature and bouquet and that the enzyme content and chemical substances are ready for further use. Afterwards, the rice-koji is cooled to prevent the fungus from reproducing any further.

Unlike in production of nihonshu, there are three different types of koji that can be used to create shochu: yellow, white and black.

Yellow koji are also used in the production of sake. As this type of koji mould is very sensitive to changes in temperature, to prevent acidification in the mash (moromi), the temperature has to be carefully monitored during fermentation. In the warm, southern regions of Japan, this poses a significant challenge. Shochu that have been produced with yellow koji are usually strong and fruity and therefore also very popular among the younger generation.

White koji are easy to cultivate and the enzymes allow for quick saccharification. For these reasons, the use of white koji mould has been widespread since the Taisho period (1912 to 1926). The final product has a refreshing, mild and syrupy flavour.

Black koji are most effective in extracting the flavour and character of the base ingredients. Black koji moulds produce a lot of citric acid, which counteracts acidification in the mash (moromi). Thanks to the what is known as the ‘new black koji’ (new kuro koji), a strong, syrupy and mild bouquet of the highest quality is achieved. Since the 1980s, new kuro koji have increased in popularity.

Making the first mash (first stage moromi)
At this point, rice-koji, water and yeast are mixed together in a vat and the first fermentation process begins. During the production of first stage moromi, the temperature has to be monitored carefully. The aim of this step is to encourage the yeast, which is responsible for alcohol production, to multiply.

Rice-koji is normally used in the production of first stage moromi. However, a trend has recently developed in which either 100 per cent barley or 100 per cent sweet potato are used.

A 100 per cent barley shochu is not made with rice-koji, but, as the name suggests, with barley-koji. Nevertheless, the preparation process for barley-koji production is basically the same: hulling, washing, soaking and then steaming the barley grains before they are covered with the koji-moulds.

Preparing the base ingredients
After this, the base ingredients are prepared and then added to the first stage moromi.

First of all, the barley (mugi) is hulled and then polished, as is the case with rice in the production of sake. Similar to the rice polishing ratio (seimaibuai) in sake, in shochu production there is a barley polishing ratio (seibakubuai), which is normally about 60 per cent. The barley grains are polished to remove any unwanted materials such as proteins and fats in the outer layer.

The sweet potatoes (imo) are first washed, sorted, steamed for about an hour and then crushed. So that the potatoes can be used in the production process, they are made smaller to lessen their fibrous consistency.

The rice that is used in the production of kome shochu is called (kome) and is invariably cultivated in Japan. So that the rice can be used in the production process, it is first washed, polished, soaked and then steamed.

In the production of sake rape shochu (kasutori / sake kasu), the residue left over after pressing out the sake is mixed into the main mash in its original form.

Sesame (goma) is added to the fermented rice-koji or barley-koji in its original form. Because of its high fat content, sesame usually only makes up 10 to 20 per cent of the mash. This stops the final product from taking on a fatty and oily flavour. Unlike in most of the varieties listed above, it is not sesame that is added to the main mash (second stage moromi), but the homogeneous liquid that was produced following the primary fermentation before this is distilled.

In the production of Awamori, it is only Thai-rice from the Indica group that is used. The grains are long, thin and the fat and protein content is low in comparison with Japonica rice. The Thai rice is washed, polished, soaked and then steamed.

Brown sugar (kokuto) is first dissolved and then added to the main mash. In comparison with the production of most of the varieties listed above, in brown sugar shochu, the sugar is not added to the main mash in one but in two stages before this is distilled. This two-stage process enables the yeast to remain active and as a result, allows for a trouble-free fermentation process.

Because buckwheat (soba) is not capable of much fermentation, a mixture of soba and rice or soba and barley is normally used in the production of soba shochu. After undergoing heat treatment, the buckwheat is hulled and added to the rice or barley mash in this state.

Making the main mash (second stage moromi)
The relevant base ingredient is added to the first stage moromi, which has completely fermented after approximately six days. The mixture is then stirred until it is homogeneous. In traditional distilleries, the master distiller still carries out this process today with a type of paddle.

In the primary fermentation, the koji moulds convert the starch in the respective base ingredients into sugar, which in turn is converted into alcohol. This process lasts approximately eight days. The result is a clean, homogeneous and somewhat viscous liquid.

By virtue of the acidity created by the koji mould, a sour, mild alcohol scent is now diffused, which corresponds more and more to the final product shochu. Up until this point, the main mash, which contains about 14 per cent alcohol by volume, still had to be distilled.

Distillation and storage
Shochu is produced with the traditional pot-still method. Alcohol distillation is intermittent. This means that only one batch can be distilled at a time, and after each one, the still has to be completely cleaned.

As far as shochu distillation is concerned, there are two methods used:
With low pressure (40 to 60 degrees Celsius), the shochu produced are more refreshing and mild. With standard pressure (approximately 90 degrees Celsius), the shochu produced are stronger and the flavour of the base ingredient is more intense.

The distilled liquid, which is abstracted through a tap, contains a very high alcohol by volume percentage of about 70 and is called hanatare. Subsequently, it is stored for about three months and as a result, it develops a mild, balanced bouquet.

Bottling
Once it has been stored, a shochu is blended or diluted with water, just as with blends in whiskies. Depending on the variety and the distillery culture, it is at this point that a shochu is bottled or, prior to this, left to mature for another few years.

Normally, shochu contains 20 to 25 per cent alcohol by volume. For shochu, the legal upper limit in Japan is 45 per cent.