This article was published on July 16, 2025, at 5:21 a.m. on the ChosunBiz RM Report site.
Regarding the method of soy sauce production, the long-standing controversy that some soy sauces are harmful to health has been brought back to the forefront. Recently, carcinogens were detected exceeding safety standards in soy sauce produced by the "acid hydrolysis method," reigniting the debate surrounding soy sauce manufacturing processes.
According to industry sources on the 16th, the Ministry of Food and Drug Safety announced that three companies, Monggo Foods, Obok Amino, and Obok Foods, had six soy sauce products that exceeded the safety limit (0.02 mg/kg) for 3-MCPD, and they will suspend distribution and initiate recall actions.
3-MCPD is a substance generated during the production process of soy sauce when plant proteins like soybeans are hydrolyzed. In 2013, the International Agency for Research on Cancer (IARC) under the World Health Organization (WHO) classified it as a "Group 2B carcinogen." This classification indicates that, while animal studies have confirmed carcinogenic effects, there is insufficient evidence in human studies.
The products subject to recall by the Ministry of Food and Drug Safety include two types of Monggo soy sauce (mixed soy sauce), two types of Obok soy sauce (mixed soy sauce), one type of Obok genuine soy sauce (mixed soy sauce), and amino acid solution (acid hydrolyzed soy sauce). Soy sauces are broadly classified based on production methods into ▲traditional soy sauce ▲brewed soy sauce ▲acid hydrolyzed soy sauce ▲mixed soy sauce. Traditional soy sauce involves fermenting and aging traditional meju, which is soy protein decomposed by natural mold, with brine. It is produced alongside doenjang (fermented soybean paste). Brewed soy sauce is produced by culturing molds with soybeans and wheat, mixing them with brine, followed by fermentation and aging.
The above two methods typically require more than six months for aging, during which 3-MCPD is almost undetectable. Traditional condiment brands mainly produce traditional soy sauce, while brewed soy sauces include clean source sunshine-aged soy sauce from Chungsungwon and Sempio brewed soy sauce.
In contrast, acid hydrolyzed soy sauce undergoes a chemical process where soybean protein is decomposed using hydrochloric acid at high temperatures, followed by neutralization and aging. In this process, 3-MCPD is generated naturally. This method allows for mass production within hours, making it widely used in commercial and processed food products. Currently, many soy sauces available in the market are in the form of mixed soy sauce, blended with brewed soy sauce rather than standing alone as acid hydrolyzed soy sauce. In fact, most of the products involved in this issue were mixed soy sauces.
The debate over whether the detection of 3-MCPD in acid hydrolyzed soy sauce is harmful to human health has been ongoing for decades. Concerns over the safety of soy sauces containing 3-MCPD were first raised in 1996, prompting the government and relevant industries to pursue measures for reducing 3-MCPD levels. After 3-MCPD became an issue for Samhwa Foods' genuine soy sauce in 2016, the standards for 3-MCPD in acid hydrolyzed soy sauce and mixed soy sauce have been gradually strengthened, setting them at 0.1 mg/kg by July 2020 and at 0.02 mg/kg starting January 2022.
However, some sectors of the industry believe that concerns over acid hydrolyzed soy sauce are excessive. 3-MCPD is also produced when cheese or bread is heated. As a result, it is often detected in products like bread, cheese, and donuts. In the U.S., the maximum allowable level is set at 1 mg/kg, while Europe, like Korea, adopts a maximum threshold of 0.02 mg/kg.
The Joint Expert Committee on Food Additives (JECFA), an international organization specializing in risk assessment, sets the maximum allowable limit at 4 micrograms (µg) per kilogram of body weight. For instance, for a 60 kg adult, exposure of up to 240 µg is considered to have no impact on health. An industry insider stated, "In Korea, the average exposure to 3-MCPD through soy sauce consumption is less than 0.002 µg per kilogram of body weight per day."
There are also calls for stricter regulations on the blending ratios and labeling of soy sauces for consumers. In particular, organizations related to traditional condiments, such as the Korean Soy Sauce Association, argue that products like acid hydrolyzed soy sauce, which are not fermented, should not be classified as soy sauce.
A soy sauce industry representative noted, "Consumers cannot know the ratio of acid hydrolyzed soy sauce to brewed soy sauce used in making blended soy sauce. Even if it's made with 1% brewed soy sauce and 99% acid hydrolyzed soy sauce, it can still be labeled as blended soy sauce. Specific labeling standards for content need to be established."
Meanwhile, the soy sauce industry is closely monitoring the potential impact of this controversy. This is because Park Jin-sun, the representative of Sempio Foods, is mentioned as a candidate for the chair of the Korea Food Industry Association. Sempio is a leading soy sauce manufacturer in Korea, producing various products, including acid hydrolyzed soy sauce.