Soy sauce

Soy sauce is a dark, savory liquid condiment with a deep umami taste.

It is a staple ingredient in East and Southeast Asian cooking. People use it as a seasoning during cooking or as a dipping sauce. It is often paired with rice, noodles, sushi, or sashimi. Some people even mix it with ground wasabi for dipping.

Because it is indefinitely shelf-stable, it is easy to store and use. This liquid is valued for its saltiness and its ability to enhance the flavor of many dishes.

Traditional production involves a complex biological process.

First, soybeans are soaked in water and boiled until they are soft. Wheat is then roasted and crushed. These ingredients are mixed to form a grain mixture. A culture of Aspergillus spores is added to this mixture. Aspergillus is a genus of fungus used for fermenting ingredients. Common species include Aspergillus oryzae, Aspergillus sojae, and Aspergillus tamarii. These molds have high proteolytic capacity, meaning they break down proteins. Other microbes like Saccharomyces cerevisiae yeast and Lactobacillus bacteria also participate. The yeast converts sugars into ethanol. The bacteria create lactic acid to increase acidity.

There are two primary methods of fermentation used today. High-salt liquid-state fermentation (HLF) is the traditional approach. In HLF, the mixture is placed in a salt brine. This requires a high salt concentration of 17% to 20%. This salinity inhibits undesirable microbes while allowing halophiles to survive. This process is slow and requires an aging period of 90 to 180 days. Constant stirring of the moromi, or mash, is necessary. Moromi is the mixture of wheat, salt, soybeans, water, and yeast. Sometimes, moromi is exposed to direct sunlight to help decompose nutrients.

Low-salt solid-state fermentation (LSF) is a modern, faster alternative. This method was created to meet high market demand. LSF uses pure cultures at higher temperatures. It also uses a lower brine concentration of 13% to 15%. In LSF, the koji is mixed with an equal weight of brine. This creates a solid moromi. The elevated temperature accelerates the fermentation process significantly. The aging period for LSF is only 15 to 30 days. This makes it much cheaper to produce than traditional methods. However, LSF may lack the flavor depth found in HLF.

The history of soy sauce begins in ancient China.

It was created in its current form about 2,200 years ago. This occurred during the Western Han dynasty. Before this, people used fermented fish with salt and soybeans. Eventually, soybeans became the principal ingredient. By the Song dynasty, the term jiàng yóu became the accepted name. In Korea, brewing began during the Three Kingdoms era. Mural paintings from the 4th century show jars used for brewing. In the Philippines, soy sauce was recorded in 1613 in documents regarding adobo.

Soy sauce has traveled across the globe through international trade. In 1647, the Dutch East India Company began exporting it from Japan. In 1737, records show seventy-five large barrels were shipped from Japan to Java. Thirty-five of those barrels were then sent to the Netherlands.

By the mid-19th century, Japanese soy sauce mostly disappeared from European markets. This was because Europeans could not access Aspergillus oryzae. Without this specific fungus, they could not replicate the brewing process. In the United States, production began in Hawaii in 1905. Before 1976, some Americans used the insulting term "beetle juice" to describe it.

Today, soy sauce is a global commodity found in almost every kitchen.

It relates to many different fields, including microbiology and food science. The dark color of the sauce comes from an amino-glycosidic reaction. This occurs when the Aspergillus mold breaks down proteins and starches. The resulting interaction between amino acids and sugars is called Maillard browning. This process creates the specific color and aroma of the sauce. Whether made through slow HLF or fast LSF, soy sauce remains a vital part of global culinary traditions.