What Is Shoyu? There Is More Than Meets The Eye When It Comes To This Condiment | CoolJapan

What essential condiment can be found on the table of most Japanese restaurants? Soy sauce, of course! Known as shoyu, Japanese soy sauce is the pillar of a lot of Japanese foods. Savoury and packed with umami notes, this well-loved condiment has the ability to elevate flavours and make a dish come alive.

Shoyu being poured

(Photo from: jcomp)

Here is where it gets better. Did you know that there are actually many types of Japanese soy sauce? The shoyu used for dipping is not the same sauce as that used in broths. Even though shoyu is made from a common base of fermented soybeans, a variation in the brewing process creates different taste profiles. Yes, just like tea and sake.

Let’s take a dip into the world of shoyu and discover more about Japanese gastronomy!

A brief glimpse into the makings of shoyu

Since centuries ago, soy sauce has been consumed by the Japanese and today, this indispensable seasoning is ingrained into the eating habits of the people. It is believed that shoyu first originated from China but it actually gained popularity within Japanese cuisine way earlier. The Japanese people loved it and by the Nara period (710-793), soy sauce was already playing a main role as a seasoning.

So is there a difference between Chinese and Japanese soy sauce? Yes, of course!

Chinese-style soy sauce uses only soybeans, while Japanese-style soy sauces are made with a mixture of soy and wheat. It undergoes a slow but complex natural fermentation process, developing in flavour and aroma over several months. This produces a clear, dark-brown sauce that is deliciously rich with nuanced flavours.

Shoyu selections in supermarket

A staggering variety of soy sauce can be found in a typical Japanese supermarket. (Photo from: Kansuke)

Throughout the years, many types of shoyu emerged, influenced mainly by regional preferences and brewing method. From the classics to varietal blends, the choices are mind-boggling. So the next question is, which type of shoyu should we buy?

The five categories of Japanese soy sauce

Koikuchi Shoyu

Sushi in Koikuchi Shoyu

Aromatic with rich flavours, Koikuchi Shoyu is the go-to soy sauce for most Japanese dishes. (Photo from: Normman)

This is the most common type of soy sauce in Japan, accounting for about 80% of domestic production. Koikuchi is probably the shoyu that most of us are familiar with as well. It is made with almost equal parts of soybeans and wheat, with a salt concentration of about 16%.

Discerning palates would have realised that besides saltiness, there is a mellow sweetness, subtle acidity and deep umami flavours. Reddish-dark brown in colour, Koikuchi shoyu has a wide range of uses and can be said to be truly versatile.

At the table, Koikuchi shoyu makes a great dipping sauce and in the kitchen, it is a wonderful seasoning for most Japanese recipes. If you are a novice Japanese cook, you will not go wrong with this all-purpose soy sauce. 

Shiro Shoyu

Shiro Shoyu on a dish

Shiro Shoyu is popular among chefs for its ability to add flavour without overpowering a dish. (Photo from: Wiki public domain)

Also known as white soy sauce, the lightest of all the soy sauce family is the Shiro shoyu. Hailing from the Hekinan district of Aichi prefecture, this pale golden soy sauce has the lightest and clearest colour because it is fermented for a shorter time.

Although it has the lightest colour, its salt concentration is as high as 18%. Using wheat as its main ingredient and a small portion of soybean, Shiro shoyu has milder umami flavours but a unique sweetness.

Shiro soy sauce does not change the colour of dishes, making it a useful seasoning in cooking and preserving the tastes of original ingredients. It can be regarded as a more flavourful substitute for salt and is good to make clear soups, tamagoyaki (sweet omelette roll) and takikomi gohan (seasoned rice).

Usukuchi shoyu

Nimono (simmered dish) with kombu, bamboo shoot, konnyaku and nameko.

Nimono (simmered dish) with kombu, bamboo shoot, konnyaku and nameko. (Photo from: Froggieboy / CC BY-SA 4.0)

Originated in the Kansai region, Usukuchi shoyu is a light-brown soy sauce with a surprisingly higher salt content of 18-19%.  This soy sauce is lighter in colour because its fermentation process is shorter. Similarly made from soybeans and wheat, Usukuchi has the extra ingredient of fermented rice.

With a milder aroma and less intense flavours, the Usukuchi is perfect for enhancing the original flavours of ingredients — just like how you would use salt in Western cooking. This clear, light-brown soy sauce is best used for cooking dishes such as soups and stews. Its light colour does not darken the appearance of the dish, resulting in a more appetizing visual experience.

Some easy Japanese recipes that you can use Usukuchi shoyu with are Udon soup, Nimono (simmered vegetables or meat) and the crowd-favourite Chawanmushi.

Saishikomi shoyu

Saishikomi Shoyu for sashimi

The full-bodied Saishikomi shoyu is particularly good for sashimi and sushi. (Photo from: João Pedro)

The special Saishikomi shoyu comes from Yamaguchi prefecture and accounts for only about 1% of Japan’s soy sauce production volume. It is often referred to as the refermented or double-brewed soy sauce because this variety is made by adding unheated soy sauce instead of salt during the brewing process.

To make the Saishikomi, twice as many raw ingredients are used and the maturation period is also longer. This creates an exquisite shoyu with a beautiful dark hue, is lusciously rich and bursting with fragrance.

As it contains more umami notes and natural sweetness than other soy sauces, this premium Saishikomi shoyu is an ideal pairing with raw fish. Besides sashimi, it also does a fantastic job in elevating the natural taste of food, such as sushi, chilled tofu and meat dishes.

Tamari shoyu

Tamari Shoyu on crackers

One traditional way to savour the rich taste of this premium soy sauce is yummy Senbei rice crackers. (Photo from: DryPot /CC BY 2.5)

Mainly produced in the Chubu region, this flavourful aged soy sauce is made primarily with soybeans. Aged for one year, the Tamari Shoyu is packed with umami, and prized for its richness and unique aromatic properties. Its slow fermentation process also results in a darker appearance and thicker consistency.

Tamari shoyu presents some of the highest umami levels of all soy sauce types, making it popular as a dipping sauce. It has a good balance of flavours and is less salty than the typical soy sauce. If you enjoy sashimi, this is the soy sauce you should go for.

You can also use Tamari shoyu for grilling meats and fish, or as a glaze. Unlike traditional Japanese soy sauce, little to no wheat is added, making it a good gluten-free alternative.