Is soy sauce vegan? (a complete guide)

This guide discusses whether soy sauce is vegan and what type of soy sauces exist in Asian cuisine. We also talk about the importance of soy sauce in various dishes.

Is soy sauce vegan?

Soy sauce is vegan because it is obtained by fermenting soybeans with cereals, water, and salt. Originally from China, it is widely used in Asian cuisine, in China, Indonesia, Japan, Korea, Malaysia, and Singapore and, to a lesser extent, in Thailand, Vietnam, Cambodia, and the Philippines.

The main fermentation processes of soy sauce are low-salt solid-state method and high-salt dilute-state method, the former of which dominates nearly 90% of the market due to its high production efficiency and low cost. Optimizing fermentation process is a key way to improve the nutritional value and flavor of low-salt solid-state soy sauce (2).

Soy sauce is made using essentially five basic raw ingredients: soybeans/soybean flakes (as the main protein source), wheat/wheat flour (as the main carbohydrate source), salt, water, and Aspergillus oryzae/Aspergillus sojae, salt-tolerant yeast and lactic acid bacteria. There are essentially two general production processes: traditional fermentation and acid hydrolysis. Acid hydrolysis, also known as “chemical hydrolysis” uses high concentrations of acid for the initial polymer breakdown of soybeans and wheat. Traditional fermentation uses starter cultures of microorganisms which secrete enzymes capable of breaking down the proteins, lipids, and starches into peptides, free amino acids, volatiles, and saccharides. Flavor and color development during the production process are attributed to enzymatic reactions, along with additional non-enzymatic Maillard reactions occurring between amino acids and reducing sugars, as well as Strecker degradation of amino acids, lipid oxidation, and esterification (3).

Salty, but much tastier and more nutritious than salt, soy sauce is an ingredient without which Asian cuisine cannot exist. 

Although there are many different soy sauce types, they all have in common the salty taste and the brown color. Its taste is difficult to describe; Asians have unique words that call it “umami” (Japanese) and “xian Wei” (Chinese), both meaning “good taste.”

Despite their appearance, soy sauces produced in different crops and regions differ quite slightly in taste, consistency, and aroma. 

The soy sauce in China

“Jiang you,” as the Chinese call it, is not a sauce in the strict sense of the word, as we Europeans perceive sauces, but a liquid extracted from salted and fermented soybeans. A name closer to reality might be the “essence” of soy. However, the name “sauce” has become commonplace, and I will continue to use it in this article.

A good quality soy sauce is as famous in China as a one-year-old wine in Europe.

During the Han Dynasty (206 BC – 220 AD), Jiang was sold along with wine, vinegar, and other liquids, which shows that it was already produced in large quantities. With the Song Dynasty (960 – 1279), Jiang was considered one of the seven daily necessities of any Chinese household, oil, rice, fuel, tea, rice vinegar, and salt.

Obtaining Jiang you (soy extract) is a long and cumbersome process. Soybeans are first cleaned, soaked, steamed, cooled, mixed with yeast culture and wheat flour, incubated for 3-5 weeks (depending on the season and local climate), fermented in brine for 6-24 days. Monday, exposed to the hot summer sun for 100 days, pressed, filtered, pasteurized, and bottled. 

The quality of the final product depends on the professionalism of the one who directs the industrial process and who supervises each stage of it: a selection of soybeans, preparation of yeast culture, proportions between different ingredients, times of each processing phase, and temperature regime. Heat-treatment/ sterilization is also an important process for the unique taste and quality control of soy sauce. Maillard reaction products remarkably increased during heat-treatment, which had an impact on the overall taste of soy sauce (1).

Avoid Chinese soy sauce brands that do not come from China, Hong Kong, or Taiwan, as most of them are prepared synthetically and do not have the naturally obtained product’s taste and aroma.

Like wine, or other alcoholic beverages, soy sauce is damaged by exposure to air (oxidation): it loses its taste and aroma. So buy small quantities and use them within 2-3 weeks of opening the bottles, if you can not store them away from air, light, and heat. Some sauces do not contain preservatives. So the safest method of storage is in the refrigerator. A study showed that the oxidation during storage caused a reduction in the phenolic compounds as well in the contents of total volatiles of soy sauce. The storage temperature and the packaging material had a great influence on these losses. Higher temperatures of storage led to greater losses and the use of PET bottles to store the product led to the decrease of the aroma compounds of the soy sauce during storage, because the PET material showed sorption of these compounds, when compared to the product stored in glass bottles (1).

As a general rule, similar to wine, light soy sauce is used in seafood, fish, white meat, vegetables, soups, or stir-fries. Dark soy sauce is suitable for red meat and heavier cooking techniques, such as baking, boiling, baking. This variety is used during cooking at higher temperatures or at longer cooking times, as it develops its aroma and taste only when heated.

The ideal mixture for dip consists of light soy sauce and one part dark soy sauce, the same proportion being suitable for marinades.

Most Chinese food is pre-seasoned in the kitchen, so although some dishes require certain specially prepared sauces or dip, there is generally no need for additional seasoning.

Other FAQs about Sauces which you may be interested in.

Does simmering thicken a sauce?

Does Thai fish sauce taste fishy?

How do you neutralize fish sauce?

The soy sauce in Indonesia

Indonesian soy sauce is called “kecap” (a term called fermented sauces, pronounced “checeap”), from which it seems to derive the English word “ketchup.”  “Kecap asin” is salty, similar to the Chinese light type, but a little thicker and with a stronger flavor; it can be replaced in Chinese light sauce recipes.

The soy sauce in Malaysia and Singapore

In Singapore and Malaysia, soy sauce is generically called “douyou.” The dark sauce is “jiangyou,” and the light “Jiang qing.” Kicap is of two types:

• “Kicap lemak,” similar to kecap manis, but less sweet.
• “Kicap cair” is the equivalent of kecap anis.

The soy sauce in Japan

The Japanese soy sauce, called “sho-yu,” has five main categories, depending on the ingredients and the production method. Chinese and Japanese soy sauces cannot be substituted for each other in recipes.

The soy sauce in Korea

Korean soy sauce, called “joseon ganjang,” is a by-product obtained from the manufacture of “donjeang” (fermented soybean paste). It has a dark color and a thin consistency and is made entirely of soy and brine. However, this sauce is about to be removed from the market by another type of soy sauce, in Japanese style, cheaper, called “waeganjang.”

The soy sauce in Vietnam

Vietnamese soy sauce, called “xi dau”, a name derived from the Cantonese language, is used mainly for seasoning, or as a dip, for a large number of dishes. However, Vietnamese cuisine uses soy sauce mainly for cooking.

The soy sauce in the Philippines

One type of soy sauce product used as a spice in Filipino cuisine is “toyo”. Filipinos also prefer to use a kind of fish sauce called “pati” and cane vinegar called “suka.”

The bottom line

Soy sauce is vegan and widely used in Asian cuisine. It is obtained by fermenting soybeans with cereals, water, and salt – it has no dairy products. 

This particular spice appeared about 2200 years ago, in western Ancient China during the Han Dynasty, where it was used to season various dishes. It spread to East and Southeast Asia and even further, gaining more and more popularity in Europe and the West. Let’s not forget the health benefits of soy sauce consumed in various dishes. The nutrients contained in soy sauce help us enjoy a healthier life. Soy sauce contains polyphenols, which have been associated with many health benefiting properties related to digestion and brain function, as well as acting as antioxidants in combating chronic diseases (3).

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References

1. Liang, Ru, et al. Characterizing the effect of packaging material and storage temperature on the flavor profiles and quality of soy sauce. J food sci technol, 2020, 57, 1544-1552.
2. Ruan, Luchen, et al. Improved umami flavor of soy sauce by adding enzymatic hydrolysate of low-value fish in the natural brewing process. LWT, 2022, 155, 12911. 
3. Diez-Simon, Carmen, et al. Chemical and sensory characteristics of soy sauce: a review. J Agric Food Chem, 2020, 68, 11612-11630.