The Quiet Power of Soy Sauce

Yuki Gomi, chef, teacher and friend of The Wasabi Company, talks us through how to learn to taste, choose and use soy sauce with intention as well as sharing her recipe for fast (but full flavoured) Kaeshi Sauce. See more from Yuki at Japanese Food. Simply. All photos by Keiko Oikawa.

I’ve always felt that an underrated hero of a Japanese kitchen is the humble bottle of soy sauce. It usually sits quietly in the cupboard, overshadowed by more glamorous ingredients like miso, yuzu or sake, yet if you explore it a little more deeply, a whole world opens up. In this article I want to share what soy sauce truly is, how it became so central to Japanese cooking, why trying different varieties is worth your time and how nine of my favourite types go far beyond the standard bottle of soy sauce many of us keep at home. At the end you will also find my recipe for a simple and reliable kaeshi sauce, something I make often and use in many dishes.

Soy sauce, or shoyu, is a fermented seasoning made from soybeans, often combined with wheat and salt. Its earliest roots trace back to China, but in Japan the style evolved into something unique. The story often leads back to the town of Yuasa in Wakayama during the 13th century, when a monk named Kakushin brought miso-making knowledge from China. The liquid that naturally separated during miso fermentation turned out to taste wonderful and became the precursor to Japanese soy sauce. Over time, especially by the Edo period, soy sauce became an indispensable seasoning in households across Japan and later an export to the wider world.

Why is soy sauce essential in Japanese cooking? First, it provides deep umami, the savoury taste that anchors nearly every soup, glaze and dressing. Second, it gives balance. Instead of adding plain salt, Japanese cooking often relies on a seasoning that has salty, sweet and savoury qualities all at once. Third, it is flexible. Soy sauce can be used for cooking, finishing and dipping. Fourth, it provides colour and aroma, which can be dialled up or down depending on the type. And finally, it offers a sense of cultural continuity. Simply using it connects your cooking back to centuries of Japanese food tradition.

If you treat soy sauce as a simple salty liquid, it is easy to overlook its potential. If you explore different bottles, however, you begin to understand that flavour, age, aroma and even colour can vary widely. This is where the fun begins. Below is a guide to nine soy sauces I enjoy and use in different ways. A big thank you to The Wasabi Company who stock several of my favourites and who have also introduced me to some rare varieties from traditional Japanese producers. All products are available to order, via the links shown below, meaning you can easily try several types from a single supplier.

3 Year Aged Soy Freeze Dried

Aged for three years and then freeze dried, this is not a typical liquid soy sauce but a powerful flavour concentrate. You can use it where you want the depth of a long-aged soy sauce without adding additional liquid. I particularly like using it in marinades or seasoning mixes when I want a mature soy flavour.

Aosa Seaweed Soy Sauce

This combines the rich umami of soy sauce with the fresh marine notes of aosa seaweed. The result is salty, sweet and umami with a clean ocean-like aroma. It works beautifully with tofu, sashimi, rice dishes, grilled vegetables and as a dipping sauce. A small drizzle instantly adds complexity.

Crystal Clear Soy Sauce

A clear soy sauce that retains flavour without colour. This is ideal for dishes where the natural appearance of the ingredients matters. It works particularly well with delicate fish, carpaccio and vegetables. Try it with fresh wasabi for a clean and refined dipping sauce.

Gluten Free Tamari from Igeta Shoyu

A deep and rich tamari made without wheat and fermented in cedar barrels for two years. The flavour is bold yet balanced, with subtle woody notes. It is excellent with sushi and sashimi and equally good for stews, marinades and sauces. It is a reliable all-purpose soy sauce that also suits gluten free cooking.

Heisei Shoyu Soy Sauce

This special edition celebrates the end of the Heisei era. Made with red sake, Kyushu soybeans and wasanbon sugar, it has a gentle sweetness and a smooth finish. I use it when I want a round, sweet flavour, especially for glazing dishes like yakitori or enhancing subtly flavoured fish.

Nama Shoyu Fresh Double Fermented Soy Sauce

Unfiltered, unpasteurised and double fermented, this soy sauce has a deep aroma and a wonderfully complex flavour. Since it is fresh and full of character, I usually serve it as a dipping sauce or drizzle it over simple dishes. It is best appreciated when allowed to shine on its own.

Organic Soy Sauce - Wasabi Company’s Brand

Made from whole organic soybeans and aged in cedar casks for at least one year, this soy sauce is clean and balanced. It contains no artificial additives and pairs well with sushi, sashimi, vegetables and marinades. When I want a pure, natural flavour, this is the bottle I reach for.

Shiro Shoyu Tsubaki White Soy Sauce

A pale soy sauce made with more wheat than soybeans. It gives seasoning without darkening your food, making it ideal for lighter dishes and colourful ingredients. It has a salty, bright flavour. It will darken if heated strongly or exposed to oxygen over time, so I store it in the fridge to help retain its colour.

Smoked Soy Sauce

Smoked over cherrywood, this soy sauce delivers a bold smoky aroma. It is meant to be used sparingly and can transform simple dishes such as poached eggs. A tiny splash adds depth to sauces, marinades or grilled foods.

---

Having a small collection of soy sauces is worthwhile for several reasons. Different dishes call for different characteristics, and no single soy sauce can provide everything. Using a variety encourages creativity and helps you refine your sense of flavour. It also makes cooking more enjoyable, because you begin to notice subtle differences that were previously invisible.

Once you start exploring soy sauces, the next step is learning how to use them efficiently. One of the most helpful tools for this is kaeshi sauce, a classic Japanese seasoning concentrate. It combines soy sauce, mirin and sugar into a ready-made base that you can turn into broths, marinades and dipping sauces in minutes.

Kaeshi has a long and quietly important history in Japanese cooking. It first developed in soba shops during the Edo period, when noodle makers needed a reliable seasoning base that could be prepared ahead of time and kept consistent from day to day. By combining soy sauce, mirin and sugar in precise proportions, they created a concentrated seasoning that could be quickly diluted into broth or used as a foundation for flavouring other dishes. Over time, every soba shop developed its own version, often guarded as closely as a family treasure. Even today, when you visit a traditional soba-ya, you can sense the pride behind their kaeshi. It forms the backbone of the entire menu.

In modern Japan, kaeshi still retains that role, but it has also become a useful tool in home kitchens. Busy cooks appreciate it because it is flexible, stores well and delivers instant balance without needing to measure out multiple seasonings. Instead of adjusting soy sauce, mirin and sugar separately every time, a good kaeshi gives you that precise sweet-savoury-salty harmony with just one spoonful. Many chefs also rely on it for consistency in sauces and noodle broths, treating it almost like a culinary shorthand for depth and balance. It is one of those quiet building blocks that links contemporary cooking back to Edo-era craftsmanship.

I find kaeshi particularly helpful on busy days. If I have a jar ready in the fridge, it means that making a noodle broth, a glaze or a dipping sauce is only a few minutes away. When I come home hungry and want something warm and simple, I often dilute kaeshi with dashi, add soba or udon, and finish with sliced spring onion. It always feels comforting and complete, no matter how quickly it comes together. I also rely on it for quick weekday cooking such as stir-fries, tofu dishes or giving vegetables a gentle sweet-savoury complexity.

Another way I like to use kaeshi is as a quiet “fixer” when a dish needs balance. If something tastes a little flat, overly salty or sharp, a small spoon of kaeshi often solves it. The sugar and mirin soften rough edges and the soy sauce adds depth, acting like a miniature reset button. It is especially useful when adjusting simmered dishes, soups or sauces, because instead of adding three seasonings separately, kaeshi brings all of them in the right ratio with almost no effort.

What I also enjoy about kaeshi is that it encourages mindfulness in seasoning. Because the base is so simple and well balanced, I find myself paying closer attention to ingredients and proportions. It brings me back to the lessons of my mentor, Chef Sekizawa, who taught me that seasoning should be intentional rather than habit. Preparing kaeshi in advance reduces the pressure later, but it also sets a calm tone in the kitchen. It makes me feel part of a long line of cooks who have relied on these same foundational flavours.

Over time, kaeshi has become more than a soba-broth concentrate in my kitchen. I use it to marinate salmon before grilling, brush it over aubergine slices before roasting, and occasionally add a touch of it to tamagoyaki for a rounder flavour. A small amount whisked into a salad dressing gives it an unmistakable Japanese character. When guests visit, I sometimes use kaeshi as the base of a dipping sauce for tempura or gyoza, which always feels like sharing a little fragment of my cooking heritage with them.

Time Saving Kaeshi Sauce Recipe

Below is my time saving kaeshi sauce. This recipe is special to me because it reminds me of my mentor, Chef Sekizawa, a master soba noodle chef in Japan. His commitment to precision taught me the importance of balance. This simple kaeshi uses only soy sauce, mirin and sugar, without dashi, and it gives a clean and versatile flavour. Coconut sugar has become my preferred sweetener for this because it adds a gentle, rounded taste.

Makes approximately 300 ml

Ingredients

• 300 ml Japanese soy sauce or tamari
• 6 tablespoons sugar (brown or coconut sugar works well)
• 90 ml hon mirin (6 tablespoons)

Method

1. Heat the mirin gently in a small saucepan until it begins to simmer and the alcohol evaporates.
2. Add the soy sauce and sugar and stir until the sugar is fully dissolved.
3. Bring briefly to the boil, remove from heat and allow to cool.
4. Transfer to a clean container and store in the refrigerator.

Some of My Tips and Notes

• Soup base for noodle broths: dilute one part kaeshi to five or six parts dashi for soba or udon.
• Simmered dishes and marinades: use as a glaze or marinade for grilled or broiled dishes such as yakitori, teriyaki or grilled fish.
• Dipping sauce: mix kaeshi with dashi or water for tempura, dumplings or chilled noodles.
• Stir-fries: add a splash to vegetables, meat or tofu for quick seasoning.
• Storage: keep refrigerated and use within about two months.

I hope this guide encourages you to explore soy sauce more deeply. Even a single new bottle can change the way you cook and taste Japanese food at home.

Enjoy experimenting and discovering your favourites, and I hope my kaeshi becomes a useful sauce in your kitchen.

 

---