Nowadays, most soy sauces are made from skimmed soybeans. Why skimmed? Soybeans contain fat and oil. When the soybeans are mashed during the process of making soy sauce, those fats float on the surface and are removed. Skimmed soybeans have the oil removed in advance, which makes this step redundant and simplifies the process, but affects the quality of the end product. Soy sauce made from whole soybeans is mellow, rich, round and sweet, and has deep umami flavour because the fatty components of soybeans are broken down into glycerine during brewing. Whole soybean soy sauce contains just the right amount of oil, so it keeps its flavour and is less likely to oxidize.
Naturally brewed in wooden barrels and matured
Most soy sauces are mass-produced in a few months. On the contrary, naturally brewed soy sauces take six months to a year until the final product is ready. Steamed whole soybeans are mixed with chopped and roasted wheat. By adding a culture of mushrooms (aspergillus oryzae) - also called "Kōji" in Japan - a dry mash is created. Salt and water are then added, and the mash is allowed to ferment. The result is brewed slowly in wood barrels. During the fermentation process, the enzymes produce amino acids, which are responsible for the umami taste in soy sauce. The wheat starch also produces sugar, which gives the sauce a full-bodied taste. These ingredients determine the colour, aroma and flavour of the soy sauce. Depending on the producer's philosophy, some soy sauces are matured for up to 5 years. Finally, the almost finished soy sauce is wrapped in cloths, pressed, filtered and pasteurised - this way it can be kept longer.
Our suppliers are Japanese traditional families. Their soy sauces are brewed without additives in cedar wood barrels that have been used since the companies were founded, some of them over 150 years ago. As they mature for another one to three years, the taste and aroma deepen and are enriched, leading to a full and complex umami.
Why “Japanese” soy sauce?
There are also soy sauces in other Asian regions like China. Chinese soy sauce often contains flavour enhancers, acidifiers and preservatives and generally have a much higher salt content compared to the Japanese ones. Japanese traditional soy sauce uses only 4 ingredients: soybeans, wheat, water and salt. There are no chemical additives nor artificial colourings. In Europe, there are also many chemically produced soy sauces. They are not made from real soybeans but from soy extract. Taste and aroma are created by chemical process and additives such as corn syrup, molasses, glucose syrup and colourings.
Are genetically modified soybeans used in our soy sauces?
No. Our suppliers are committed to making traditional soy sauce and do not use genetically modified soybeans. Genetically modified soybeans have been genetically engineered to create a special enzyme that prevents herbicides from killing it. In Japan, there is no requirement to indicate the presence of genetically modified soybeans since the soy protein is broken down during the brewing period and is not detected in the product.
Light or dark in colour, or Tamari… what’s the difference?
Here are the main types of soy sauces:
- Koikuchi - "dark soy sauce" - is the most typical Japanese soy sauce. It contains soybeans and wheat in roughly equal proportions. It accounts for about 80% of the total production in Japan.
- Usukuchi - "light soy sauce" - the proportion of wheat is higher, it also has a higher salt content. Its share in the total production is about 10%.
- Saishikomi - "double brewed soy sauce" - this soy sauce is double fermented, which gives it additional complexity in taste.
- Tamari - consists mainly of soybeans. It accounts for 1% of the total production.