Soy sauce is a staple condiment in many households and restaurants around the world. But have you ever wondered how this savory, umami-rich sauce is made?
The answer lies in the process of fermentation. Fermentation is a crucial step in the production of soy sauce, and it’s what gives this condiment its unique flavor and aroma.
In this article, we’ll take a closer look at how soy sauce uses fermentation to create its signature taste and explore the history behind this beloved condiment.
So, grab a bottle of soy sauce and let’s dive in!
How Does Soy Sauce Use Fermentation?
The process of making soy sauce involves four main ingredients: soybeans, wheat, salt, and water. However, it’s the process of fermentation that transforms these simple ingredients into the complex and flavorful condiment that we know and love.
The first step in the fermentation process is to create a koji mixture. This is done by combining steamed soybeans and roasted wheat with a specific strain of mold, usually Aspergillus oryzae or Aspergillus sojae. The mixture is then left to ferment for several days in large wooden vats. During this time, starches are broken down into simple sugars, proteins into amino acids, and oils into fatty acids.
The koji mixture is then combined with water and salt to create a moromi, or solid-state mash. This mixture is then fermented with lactic acid bacteria and yeast for several months. The secondary fermentation process is what creates the hundreds of flavor molecules found in soy sauce. The longer the fermentation process, the deeper the flavor profile becomes.
One of the key players in this fermentation process is the salt-tolerant yeast Zygosaccharomyces rouxxi. This yeast contributes to the characteristic toasty, malty flavors of soy sauce. Other major flavor products include ethanol and lactic acid.
After completion of the fermentation process, the raw soy sauce is filtered and pressed through cloth. The liquid filtrate is then pasteurized and bottled.
What Is Soy Sauce?
Soy sauce is a condiment that is commonly used in Asian cuisine. It is a dark, salty liquid that is made from soybeans, wheat, salt, and water. The fermentation process is what gives soy sauce its unique flavor and aroma. During fermentation, enzymes break down the proteins and carbohydrates in the soybeans and wheat to create amino acids, simple sugars, and fatty acids. These compounds then interact with the salt and other microorganisms to create hundreds of different flavor molecules. The resulting soy sauce can vary in sweetness, acidity, saltiness, aromaticity, texture, thickness, and the intensity of caramelization. Soy sauce is often used as a flavor enhancer for a variety of dishes, including meats, vegetables, soups, and noodles. It has also been found to have preservative properties due to its acid, alcohol, and salt content. Overall, soy sauce is a versatile and flavorful condiment that has been enjoyed for centuries.
The History Of Soy Sauce
Soy sauce has a long and rich history that dates back to ancient China over 2,500 years ago. The original predecessors of soy sauce were jiang and chi, which were made by fermenting meat or fish and soy nuggets respectively. During the Han dynasty around 220 BCE, Buddhism was beginning to expand into China from India, and one of the precepts for Buddhists includes refraining from harming living beings. As a result, the original fermented sauce was split into two different fermentation products to prevent monastic and lay practitioners from eating foods produced from animals – fish sauce, and soy sauce as the vegetarian alternative.
Soy sauce’s origin can be traced back to the need to preserve meats, vegetables, and grains with salt. The wheat was fermented with soybeans, water, and salt. Soybeans eventually became the primary ingredient in this combination that came to be known as soy sauce. Several hundred years later, this process was introduced to Japan and from there it spread to the rest of Asia. It was first exported to the U.S. in the 1800s.
The traditional method of making soy sauce requires several months and involves creating a grain mash from boiled soybeans and roasted, crushed wheat. Different types of yeast cultures are then added to this mash. The mixture is then brewed with a wet or dry salt brine, breaking down the ingredients through first and secondary fermentation into flavor compounds that characterize what we know is soy sauce in all its depth of flavor, or umami glory.
Today, there are many different types of soy sauces available, ranging from plain soy sauce to light to dark and even double dark. They vary by flavor, texture, and color. Of the brewed kind, light soy sauce is thinner and lighter in color, leans toward the saltier side, and is meant to accent the flavors of what is being cooked. Blended soy sauces are brewed but are then blended with sweet or savory elements to add a different layer of flavor, texture, or color. In this family, dark or old soy sauce is sweeter and less salty and might even have molasses or caramel color added, developing more flavors as it cooks. Other blends include mushroom or shrimp, great for finishing a dish.
The Fermentation Process
The fermentation process of soy sauce is a crucial step in creating the complex and unique flavor profile of the condiment. The process begins with the creation of a koji mixture, which is made by combining steamed soybeans and roasted wheat with a specific strain of mold. The mixture is then left to ferment for several days in large wooden vats. During this time, starches are broken down into simple sugars, proteins into amino acids, and oils into fatty acids.
The next step is to create a moromi, or solid-state mash, by combining the koji mixture with water and salt. This mixture is then fermented with lactic acid bacteria and yeast for several months. The secondary fermentation process is responsible for creating the hundreds of flavor molecules found in soy sauce. The longer the fermentation process, the deeper the flavor profile becomes.
One of the key players in this fermentation process is the salt-tolerant yeast Zygosaccharomyces rouxxi. This yeast contributes to the characteristic toasty, malty flavors of soy sauce. Other major flavor products include ethanol and lactic acid.
Once the fermentation process is complete, the raw soy sauce is filtered and pressed through cloth. The liquid filtrate is then pasteurized and bottled. It’s important to note that there are two main methods for making soy sauce: traditional brewing, or fermentation, and non-brewed methods, or chemical-hydrolyzation. The traditional brewing method takes up to six months to complete and results in a transparent, delicately colored broth with balanced flavor and aroma. The non-brewed sauces take only two days to make and are often opaque with a harsh flavor and chemical aroma.
The Role Of Microorganisms In Soy Sauce Fermentation
Microorganisms play a crucial role in the fermentation process of soy sauce. The koji mold, which is added to the mixture of soybeans and wheat during the initial stage of fermentation, breaks down the proteins into simple amino acids. These amino acids include glutamic acid and glutamine residues, which are essential in creating monosodium glutamate (MSG) – the primary flavor enhancer in soy sauce.
During the secondary fermentation process, lactic acid bacteria and yeast are added to the mixture. The lactic acid bacteria lower the pH of the moromi, resulting in the acidic pH range of soy sauce products, while the yeast contribute to the toasty, malty flavors of soy sauce. The fermentation process also breaks down starch into simple sugars, which contribute to the sweet flavor of soy sauce.
The microorganisms involved in the fermentation process vary depending on the region and type of soy sauce being produced. Different strains of mold and bacteria can produce different flavor profiles, giving rise to a wide range of soy sauce flavors.
Types Of Soy Sauce And Their Fermentation Methods
Soy sauce can be broadly classified into two types based on their fermentation methods: traditional brewed soy sauce and chemical-hydrolyzed soy sauce.
Traditional brewed soy sauce, also known as natural fermented soy sauce, is made using the traditional fermentation method. This method involves the use of koji mold, lactic acid bacteria, and yeast to ferment a mixture of soybeans, wheat, salt, and water. The fermentation process can take up to six months and results in a transparent, delicately colored broth with a balanced flavor and aroma. The longer fermentation time allows for a deeper flavor profile and a more complex taste. Traditional brewed soy sauce is considered to be of higher quality than its non-brewed counterpart.
Chemical-hydrolyzed soy sauce, also known as non-brewed soy sauce, is made using a chemical process that involves the hydrolysis of soy protein. This method is much faster than the traditional brewing method and takes only two days to produce. However, the resulting soy sauce is often opaque with a harsh flavor and chemical aroma. The non-brewed method is commonly used in industrial production due to its efficiency and lower cost.
There are also different types of soy sauces within each category based on regional variations in ingredients and fermentation processes. For example, Japanese soy sauce tends to have a sweeter taste compared to Chinese soy sauce, which is saltier. Tamari soy sauce is a type of Japanese soy sauce made without wheat and has a richer flavor profile.
Health Benefits Of Soy Sauce
Soy sauce has been used for centuries in Asian cuisine, and it’s not just for its delicious taste. Studies have shown that soy sauce contains antioxidants and anti-inflammatory properties that can provide several health benefits.
One of the main health benefits of soy sauce is its potential to aid digestion. Soy sauce contains enzymes that help break down proteins and enhance gastric juice secretion, which can improve overall digestion. Additionally, the fermentation process of soy sauce creates beneficial bacteria that can support the growth of healthy gut flora.
Another benefit of soy sauce is its potential to lower cholesterol levels. Soy contains isoflavones, which are compounds that have been shown to improve cholesterol levels in the body. However, it’s important to note that soy sauce should be consumed in moderation due to its high sodium content.
Soy sauce also has potential anti-allergenic properties. The fermentation process of soy sauce breaks down proteins into amino acids, which can reduce the likelihood of allergic reactions. However, those with soy or wheat allergies should be cautious when consuming soy sauce and should opt for gluten-free or tamari varieties.
