Soy sauce (shoyu, raw?, organic?)

Soy sauce (shoyu) is a traditional Japanese seasoning sauce made from fermented soybeans and wheat. It is available in organic quality and an unpasteurized soy sauce is now available on the market, although it is not raw in the sense of being raw food.

Use in the kitchen

What is shoyu? 'Shoyu' is the Japanese word for 'soy sauce'. Shoyu is a Japanese-style soy sauce. It is made from soybeans, wheat, water, sea salt and molds of the genus Aspergillus ⁸, which are often called 'koji' in Japanese. ²¹

In Japanese cuisine, different variants of Shoyu are used: 'Koikuchi-Shoyu', 'Usukuchi-Shoyu', 'Tamari-Shoyu', 'Saishikomi-Shoyu' and 'Shiro-Shoyu'. They differ in color, taste and salt content. ²² We briefly introduce three of these sauces here:

The most common is the Koikuchi-Shoyu. This is also simply called Shoyu. Koikuchi-Shoyu has a dark brown color and a rich aroma. The salt content is on average 17 to 18%; one tablespoon of Shoyu contains about ½ Teaspoon of salt. Koikuchi-Shoyu is used for sauces, soups and stir-fried dishes or simply as a dip. Koikuchi-Shoyu gives dishes a dark brown color, a wide range of flavors and is a little milder than tamari, for example. ¹

The second type of soy sauce is usukuchi shoyu - the light soy sauce. To make light shoyu, the wheat is only lightly roasted. In addition, more salt is added to slow down the fermentation. Sometimes a little mirin (sweet rice wine) is also added. This shoyu is lighter, the taste is less strong and the soy sauce contains a little more salt (19%). Therefore, light shoyu is used in recipes in which a too dark color and too strong a taste are undesirable (e.g. in soups). ¹

The third type is Tamari -Shoyu. Tamari is traditionally only produced in a few Japanese prefectures: Aichi, Gifu and Mie. Tamari consists mainly of soybeans. It therefore contains little to no wheat. Only a small amount of water is added for fermentation. After 20 months of fermentation, Tamari is slightly thicker than the other varieties. In contrast to the other Shoyus, Tamari is not used as a "basic ingredient", but only sparingly as a seasoning sauce to enhance the flavor. Tamari should only be added at the end of the cooking time. ¹

The sweet soy sauce Ketjap-Manis is a thick seasoning sauce from Indonesia, sweetened with palm sugar.

The most important thing when cooking with shoyu is to heat the soy sauce carefully. Brief cooking preserves the natural aroma, taste and color. Due to the high salt content, shoyu should also only be added to cooked dishes towards the end of the cooking time so that the ingredients do not lose too much juice. However, this effect can be particularly delicious in some dishes: If you fry tofu with shoyu, the tofu loses water and you get a crispy, browned tofu. Sesame goes particularly well with this. When cooking pan or wok dishes, you can let shoyu run over the hot edge of the pan at the end. This quick "burning" gives the dish a caramelized taste. ¹

Shoyu is a wonderful ingredient for pickling and marinating. The soy sauce has a high salt content, mild acidity (pH is around 4.8) and low alcohol content. All of these properties make it useful for preserving food. ¹

Due to the manufacturing process, shoyu has a special taste - 'umami'. 'Umami' is the fifth taste that we can perceive with our taste buds, alongside sweet, sour, bitter and salty. This taste is often described as savory and meaty. ¹³

A classic question when cooking with salty ingredients is: what do I do if I use too much? How can I compensate for too much soy sauce? Although you can mask the salty taste with sweet or sour ingredients, it is recommended to dilute the dish. Too much salt at once can be very unhealthy (more on this in the chapter 'Effects on Health').

Vegan recipe for broccoli with shoyu dressing

Ingredients (serves 2): 1 broccoli, 1 tsp Dijon mustard, 1 garlic clove (diced), 60 ml komezu ( rice vinegar), 2 tsp finely grated carrot, 1 ½ tsp finely grated onion, 1 tsp ginger juice (or grated ginger), 2 tsp shoyu, ½ tsp corn syrup, 2 tsp sesame seeds (coarsely ground and roasted), 60 ml rapeseed oil, 1 tsp sesame oil.

Preparation: Mix all the ingredients in a large bowl, except the sesame oil and broccoli. Cover and place the dressing in the fridge for 30 minutes. Meanwhile, cut the broccoli into florets and wash well. Then steam for about 2-4 minutes. Take the dressing out of the fridge. To serve, drizzle the broccoli with the sesame oil and garnish with a generous amount of the dressing. This goes well with rice, shirataki noodles or fried tofu.

Vegan recipes with soy sauce (shoyu) can be found under the note: " Recipes that have the most of this ingredient ".

Purchasing - Storage

Soy sauce (Koikuchi) Shoyu is available all year round in large supermarkets such as Coop, Migros, Denner, Volg, Spar, Aldi, Lidl, Rewe, Edeka, Hofer, Billa, as well as in Japanese and Asian grocery stores. Health food stores, organic food stores and organic supermarkets such as Denn's Biomarkt or Alnatura sell Shoyu made from organically grown wheat and soybeans, some of which are also produced using a traditional process. Usukuchi-Shoyu, the light soy sauce, is mainly found in Japanese grocery stores. However, this is almost always interchangeable with Koikuchi-Shoyu, even if dishes with Koikuchi-Shoyu have a stronger color and a stronger Shoyu flavor.

There is also reduced-salt soy sauce (Genen Shoyu). Low-salt shoyu usually contains preservatives and other additives that replace the salt (and its preservative effect). ¹

The availability of soy sauce (shoyu) varies depending on the size of the store, catchment area, etc. You can find our recorded food prices for the DA-CH countries above under the ingredient image - and by clicking you can see their development at different suppliers.

Storage tips

Unopened soy sauce (shoyu) lasts for about one and a half years. Once opened, you should store the soy sauce in a cool place, tightly sealed. The refrigerator is a good place for this. ¹

Ingredients - Nutritional values - Calories

The ingredients of soy sauce (Shoyu) offer 53 kcal/100g. Of this, 0.57 g/100g is fat. Carbohydrates are 4.9 g/100g and proteins 8.1 g/100g. Soy sauce contains a lot of salt: this example sauce contains 14 g/100g of table salt, which is many times the daily requirement (581.3%). ²

Among the essential micronutrients in soy sauce, manganese is particularly important. At 1 mg/100g, it contains 51% of the daily requirement. Of course, you don't eat that much soy sauce: you take about 10-20 g of soy sauce per meal (1-2 tablespoons). A better source of manganese is pine nuts (8.8 mg/100g) or brown rice (4 mg/100g). ²

The soybeans also contain amino acids, e.g. tryptophan with 0.1 g/100g. Rusks and rice flakes contain a similar amount. This is not an insignificant amount when you consider that protein-rich chickpeas (raw) contain 0.2 g/100g. You can get more tryptophan from whole foods: e.g. goa beans (0.76 g/100g) or whole soybeans (0.59 g/100g). ¹

Threonine – a truly essential amino acid – is found in soy sauce at 0.27 g/100g. Similar amounts are found in wholegrain rice and soft wheat semolina. More of it is found in lupin flour (1.4 g/100g) and other pulses ( kidney, soy or goa beans). ²

In addition, soy sauce contains large amounts of potassium (435 mg/100g) and isoleucine (0.32 g/100g). ¹

The alcohol content (ethanol) in soy sauces varies and ranges from 1-3% vol. ²¹

In addition to nutrients, soy sauce (shoyu) also contains bioactive substances with antioxidant effects, among other things. Firstly, secondary plant substances from the soybean and secondly substances created by fermentation with koji: polyphenols (isoflavones, furanones, pyranones), melanoidins, free amino acids (proline, leucine and aspartic acid), furan ketones, phenolic acids, organic acids, β-carbolines and peptides with low molecular weight. ^3,7 In the next section, you will learn what effects these substances can have on our health.

The complete ingredients of soy sauce (shoyu), the coverage of the daily requirement and comparison values with other ingredients can be found in our nutrient tables. In the article Nutrients explained you will get a detailed insight into the topic.

Effects on health

How healthy is soy sauce? Or should we ask: How unhealthy is soy sauce? Whether a food is healthy or unhealthy for us depends, of course, on many individual factors: quantity, production process, predisposition and lifestyle aspects. ⁶ Nevertheless, here is an attempt to summarize the effects of soy sauce (shoyu) on health. Unfortunately, studies too often emphasize one-sidedly positive aspects, because they are usually created for the purpose of being able to sell or promote something more credibly.

The following effects have been observed in studies to date: promotion of gastric secretion, blood pressure lowering effect, antimicrobial activity, anticarcinogenic effects and the soy sauce is said to help prevent cataracts. ⁵ In addition, antioxidant effects, antihyperuricemic (hyperuricemic = increased uric acid levels → factor for gout) and platelet aggregation-inhibiting activities have been shown. Platelet aggregation inhibitors prevent blood platelets from sticking together and thus reduce the body's ability to form blood clots. ⁷

However, the underlying studies are rare and the effects have not been fully researched. A 2019 study tested the physiological effects of soy sauce on nematodes ( Caenorhabditis elegans). The researchers observed that the nematodes that were fed soy sauce stored less fat than the control group that was given salt water. An earlier study showed that salt promotes fat accumulation. ⁹

Does soy sauce reduce fat accumulation? Interestingly, the consumption of soy sauce had the effect of reducing the accumulation of fat in the bodies of the nematodes, despite the high salt content. The reason for this is still questionable, however, and the results cannot be transferred to humans with certainty. ⁹

This study also showed that soy sauce has an antioxidant effect (keyword: secondary metabolites). Oxidative stress is closely linked to our health. It damages our cells and DNA, which causes us to age faster and leads to various diseases. The nematodes reacted with an increased tolerance to oxidative stress after consuming soy sauce. ⁹

Increased resistance to pathogens was also observed in the nematodes. Soy sauce increased the expression of several anti-stress genes. ⁹

Since C. elegans has many genes that are similar to those of higher animals (including humans), the results of this study could also be extrapolated to humans. ⁹

Dangers - Intolerances - Side effects

Soybeans and wheat are among the eight most common allergens. Paradoxically, soy sauce - which contains both wheat and soy - has an anti-allergenic effect. During fermentation, microorganisms completely break down the allergens. ⁵

Nevertheless, allergic reactions can sometimes occur. However, it is unclear whether this is due to the histamine contained or other substances. ¹⁶

Too much salt – according to the WHO, that is more than 2 g of sodium or 5 g of salt per day for healthy adults ²⁴ – is unhealthy for us humans. To illustrate: a level teaspoon of salt weighs about 5 g; a tablespoon of soy sauce contains about 1.4 g of salt. High salt consumption, although this can vary from person to person, increases the risk of cardiovascular disease and high blood pressure. ²⁰

Soy sauce (shoyu) may also contain sugar or other additional ingredients – please read the manufacturer’s ingredient list.

Carcinogens can form during the production of soy sauce through chemical hydrolysis. The byproduct ethyl carbamate (EC) is also a concern for manufacturers. ²¹ Although EC is considered moderately toxic, the IARC ( International Agency for Research on Cancer) has classified it as "probably carcinogenic to humans". ²⁵

Ecological footprint - animal welfare

The CO ₂ footprint of soy sauce is approximately 0.65-1.2 kg CO ₂ eq/kg ¹¹ - according to a Danish calculation, even 1.64 kg CO ₂ eq/kg. This value can vary depending on the growing area, production method and packaging.

The water footprint is approximately 600-1986 l/kg. ^10,12 We could only find two studies on this, with the higher value being based on a calculation that used soy sauce without wheat.

To illustrate: Meat and fish, which are also said to have the taste 'umami', cause a CO ₂ footprint of 13.6 (beef, average) and 2.4 kg CO ₂ eq/kg (fish, wild caught, mass produced, frozen). ¹⁴ Other condiments, such as ketchup or mustard, have a greenhouse gas effect of 1.9 and 1.8 kg CO ₂ eq/kg respectively. ¹⁵

For detailed explanations of various sustainability indicators (such as ecological footprint, _CO2 footprint, water footprint), see our article: What does the ecological footprint mean?

Animal welfare - species protection

Growing soy involves some ecologically problematic aspects. This is not due to the plant itself, but to the production method. Read about this under the ingredients soybean or soy milk.

Worldwide occurrence - cultivation

Shoyu is a soy sauce made according to Japanese tradition. This country therefore produces Shoyu in particular and exports the soy sauce all over the world. There is now also Shoyu that is produced in the EU from regional and organic ingredients, for example in Germany.

The invention of soy sauce can be traced back to China. The first soy sauce was called 'jan'. It is not clear when soy sauce came to Japan. According to one report, a Zen monk named Kakushin discovered 'hishio', a mixture of soy sauce and miso paste. Kakushin brought miso from China to Japan in 1254. When he taught the production of miso in a village, he noticed that the liquid that was produced tasted excellent. This was the beginning of Tamari Shoyu. The first Japanese soy sauce business was founded around 1580. ¹⁷

The internationalization of Japanese soy sauce began in the Edo period (1688-1736). At that time, Japan was in a phase of national isolation, but trade between Nagasaki and Holland was the only exception allowed. Dutch and Chinese ships began to transport Japanese soy sauce to mainland China, other parts of Southeast Asia, and as far as Holland. Soy sauce was not transported in barrels, but in earthenware bottles called 'konpura bottles'. After that, soy sauce reached more and more countries. The versatile seasoning can now be found in kitchens all over the world. ¹⁷

Industrial production

According to connoisseurs, the shoyu bouquet has more than two hundred components that result from the lengthy fermentation process. For the sauce to reach this level of complexity, it takes at least 12 to 24 months using traditional (fermented) manufacturing methods. The basic ingredients used are soybeans, wheat, spring water, koji and sea salt. The wheat is roasted beforehand. The soybeans must be soaked in water and steamed in preparation. The wheat is then mixed with the soybeans and koji is added. Over the next 40 hours, the koji mold multiplies in the mixture. The sweet-smelling brew is then mixed with salted spring water and left to ferment in a wooden barrel for up to a year. While the high salt content prevents the growth of undesirable bacteria in the barrel, the good koji mold converts the proteins into amino acids and the starch into sugar, alcohol and organic acids. These give the shoyu its rich flavor and hundreds of aromatic compounds. Fermentation also increases the nutritional value of shoyu. The bacteria synthesize enzymes and vitamins and ensure a better amino acid balance. After fermentation and maturation, the mixture is pressed to separate the liquid (shoyu) from the mash. ¹ This special fermentation is also called 'moromi'. ^8,21

Finally, the soy sauce is filtered and heated to stop fermentation, sterilize it, and create an additional flavor component - a kind of caramel flavor. ²¹ Thanks to advanced cooling and transportation technologies, Japanese manufacturers can now sell non-heat-treated shoyu, called 'kijoyu' or 'namashoyu', which is still biologically active. Unpasteurized shoyu has a distinctive robust, natural flavor that some prefer. But even this soy sauce is not a raw product, because soybeans are only edible after being heated!

Most shoyu is now produced using a shortened, highly automated process. Fermentation takes place in temperature-controlled tanks, which reduces production time to four to five months. If production only takes a few days, it is acid-catalyzed production (read more about this under Tamari). The result is a shoyu that has fewer flavor components than a traditionally produced soy sauce. ¹ Not only does the taste suffer from the quick method, the health effects can also be worse. ^{21, 23}

More information

The koji mold used in soy sauce production is a filamentous fungus belonging to the genus Aspergillus. Three species are mainly used: Aspergillus oryzae, Aspergillus sojae and Aspergillus tamarii. A. oryzae is used in the production of sake, amazake (Japanese sweet drink), mirin (Japanese sweet rice wine), miso and soy sauce; while A. sojae is only used in the production of miso and soy sauce. A. tamarii is rarely used. ^19,21

Aspergillus niger is also interesting for the production of 'koji' because it increases enzymatic activity. ⁴ The wild ancestor Aspergillus flavus is a major producer of toxic aflatoxins, but also of antibiotics. The propagation and harvesting of molds for the production of soy sauce is a complex issue. ^{4, 18}

In addition to koji, halophilic (salt-loving) lactic acid bacteria and salt-tolerant yeasts are also involved in the fermentation process. ¹⁹

At the beginning of the 20th century, the Japanese chemist Kikunae Ikeda discovered that glutamic ions trigger a taste sensation of their own. He called this taste 'umami', which roughly means 'meaty, spicy, savoury'. He suspected that 'umami' is a signal for the ingredients of food, like the other flavours. There are theories that 'umami' signals when food contains proteins (proteins alone have no taste). Or it signals digestible proteins, such as those produced by cooking or fermentation. Another possibility is that it signals probiotic bacteria. However, these theories have not yet been confirmed. Much about 'umami' is unclear and still needs to be researched. ¹³

Alternative names

Shoyu is the Japanese word for soy sauce. In English it is called 'soy sauce' or just 'shoyu'.