The Chemistry of Soy Sauce

IntroductionSoy sauce is a condiment unique to Asia. Being part chinese, my mother as well as relatives from her side of the family use soy sauce in many asian dishes. It is a part of my culture and i love to use it in food.

Composition of ...

Soy sauce is first made by soaking soybeans in water and steaming them. Wheat is then roasted and crushed to begin fermentation. It is the carbohydrates that give the sauce the aroma and the sweetness. Salt is dissolved in water to control bacteria growth. A key factor in the making comes from the Aspergillus, a type of fungus, to to increase the growth of koji mold. this is mixed with soybeans and wheat and is moved to an environment suitable for koji mold growth. The koji is then mixed with a salt water solution and is aged and fermented in a tank. During the fermentation period, processes such as lactic acid fermentation, alcoholic fermentation and organic acid fermentation take place each are essential to the flavor, aroma, and color to the sauce. After aging the soy sauce is then pressed from the mixture and strained through three layers of fabric. the process continues for numerous hours to produce a rich color and flavor. The product known as raw soy sauce is left in a clarifier tank for three to four days to separate its many components. The soy sauce is then ran through a steam pipe to heat it for pasteurization purposes as well as stopping the activity of enzymes and preserving color and taste.

Chemistry's Role

Carbohydrates in the wheat give the sauce its aroma and flavor.

During the aging period, the aspergilus mold breaks down the proteins and starches into amino acids and sugars. Then lactic acid bacteria transitions the sugars into lactic acid while The molds and koji produce ethanol.

Through proper fermentation the optimal flavor and aroma for rich soy sauce is produced.

ethanol fermentation

C6 H12 O6 ---> 2 C2 H5 OH + 2 CO2 + NRG

Glucose ---> Alcohol + carbon dioxide + NRG

lactic acid fermentation

C6H12O6 --> 2C3H6O3+2ATP

Sugar (glucose) → Lactic Acid + Carbon Dioxide + Energy (ATP)


About the Author

Matthew Orion Oyola is a junior at senior high who enjoys music and comics. Being of Asian and hispanic descendants, he is very open to trying new foods his favorites being from asian and hispanic cultures. He greatly enjoys the company of his closest friends and causing mischief so watch your back.