Make Traditionally Hand-Brewed Soy Sauce at Home and Brew Up an Authentic Soy Aroma

Many friends are used to the bottled soy sauce in supermarkets, but actually with the most traditional handmade method, you can brew a jar of richly soy-aromatic purely brewed soy sauce at home too. Handmade brewing does not rely on additives for flavor, but on time and the natural fermentation of microorganisms. The soy sauce made this way tastes mellow and carries a sun-dried sunshine aroma. Below, let us walk you through the basic method and precautions for handmade purely brewed soy sauce.

Brewing principle: microorganisms are the main players

The core of purely brewed soy sauce is that soybean protein and wheat starch slowly decompose under the action of microorganisms. First boil the soybeans and mix in flour, then inoculate with Aspergillus to make soy koji. The enzymes secreted by Aspergillus break down protein into amino acids, which is the main source of the umami of soy sauce; starch is converted into sugars, giving the soy sauce sweetness and a bright red color. After that, add salt water and carry out a long period of sun by day and dew by night. Yeast and lactic acid bacteria continue to ferment, and rich layers of flavor accumulate little by little in this way.

Basic steps of handmade brewing

The first step is selecting materials and steaming the beans. Choose plump soybeans free of mold, soak them thoroughly, then steam them until they break apart with a pinch of the fingers, spread them out and cool until not hot to the touch. The second step is mixing with powder and making koji. Mix the cooled cooked beans with roasted wheat flour, spread them in breathable containers such as bamboo trays, and place them in a warm, ventilated place to culture. After a few days, the surface of the beans is covered with yellow-green spores, and the soy koji is made. The third step is putting it into the jar to sun-brew. Put the soy koji into a clean container, add a relatively high concentration of salt water and mix well, seal the mouth of the jar with gauze to prevent dust and insects, sun it by day and dew it by night, and stir often during this period so fermentation is even. Generally it must be sunned for several months, until the color of the soy mash turns dark and the soy aroma is obvious, before it is considered mature. The fourth step is drawing off the oil and sterilizing. After maturity, you can take out the raw soy sauce by drawing off the oil, or press and filter it, then boil it to sterilize and bottle it for storage.

These details must not be ignored

First, hygiene. All utensils must be washed and sun-dried, hands washed before handling, and the koji-making and sauce-sunning stages are the most afraid of contamination by stray bacteria. Once it turns black and smells bad, decisively give it up, do not be reluctant. Second, the salt amount must be sufficient. The concentration of salt water must not be lowered at will, otherwise it easily spoils and turns sour. Better to be on the salty side than to take the risk. Third, the environment must be stable. In the koji-making stage, if the temperature is too low the Aspergillus will not grow well, and for sunning the sauce, choose a spot with ample light and good ventilation, and pay attention to rain protection and moisture protection on rainy days. Fourth, have patience. Traditional pure brewing relies on sun by day and dew by night, and the cycle is counted in months. It cannot be rushed.

Handmade soy sauce brewing is not hard to say, the key lies in care and patience. For the first jar, do not be greedy for quantity; try it on a small scale, and after gaining experience, expand the scale. This way you can experience the joy of traditional agricultural product processing, and the whole family can eat soy sauce with more peace of mind.