Chili soy sauce is a type of Asian sauce that gives foods a salty, sweet, sour, bitter, and spicy flavor. The sauce is made by combining soy sauce with either chili sauce or fresh chilies. Many companies make their own variations of chili soy sauce, but it is also easy for people to make at home. The sauce is usually used in Asian cuisine but can enhance the flavor of dishes from all over the world.
Asian cuisine has made use of a sauce similar to modern soy sauce for thousands of years, but in its modern form, soy sauce has only been made since the 1700s. The process of making this type of sauce is quite involved and requires multiple fermentations. In the first fermentation step, salt water, soy beans and crushed wheat are cooked and then combined with aspergillus, which is a type of mold. This mixture is allowed to sit for a few days before bacteria and yeast are added. Over the next few months, the yeast consumes sugars in the wheat and soy and excretes alcohol while the bacteria consumes lactose and secretes lactic acid. The resultant sauce is salty, bitter, sour and slightly sweet from the residual sugars left in the wheat.
Many types of Asian cuisine attempt to balance each of the flavors in a dish. Soy sauce is considered to be a good balance of the four flavors it represents but does not include spiciness, which is an important component in many dishes. Chili soy sauce gives dishes the heat that regular soy sauce lacks.
Though they are commonly used in Asian cuisine, chilies were only introduced to this part of the world in the 1500s, once explorers started bringing plants from North and South America to Europe, Asia, and Africa. The flavor of chilies was so popular that they quickly worked their way into many traditional dishes and sauces from all over the world, becoming an intricate component of many types of cuisine. Chili sauce is made by combining chopped chili peppers with a liquid, such as vinegar, oil, alcohol or water. The sauce can be eaten right away but most preparations also allow it to keep for long periods of time. Though chili soy sauce is a relatively new food, the combination of a chili sauce and a soy-like sauce is not a new idea.
Making chili soy sauce is as simple as combining these two types of sauces together. The process of making soy sauce is quite intricate, and the chilies do not benefit from the fermentation process so there is no reason to combine chilies and soy sauce before the soy sauce has finished fermenting. Any kind of chili sauce can be added to soy sauce to give it heat, but Asian chili sauces are usually preferred. It is also possible to allow sliced or chopped chilies to sit in soy sauce in order to infuse the soy sauce with the heat of the chilies without altering its flavor profile significantly.