There's a lot more to soy sauce than this bottle. Soy sauce is one of Asia's greatest culinary exports: it's used in so many cuisines today, and it represents a positive side of globalism that wouldn't exist otherwise. However, soy sauce is widely misunderstood as something to pour over white rice (don't do that please) or Chinese takeout food, but it hasn't reached national awareness yet that it can be an artesanal product just like beer and wine. It is one of the most complex, intricately flavored ferments in existence; sustainable and environmentally friendly; and it's relatively inexpensive. The English word soy comes from the Japanese term shoyu for soy sauce, which originally stems from Chinese jiangyou , or literally oil on the surface of bean paste. Shoyu is one of the most complex fermented foods, as it involves aspergillus oryzae molds, LAB, and yeasts in two distinct forms, all of which have different metabolisms and byproducts. There are two main types in Japan: tamari, which is made with soybeans alone, and shoyu, which contains wheat and soybeans. It's easy to confuse miso and soy sauce in their process, as soy sauce was originally invented from the miso making process, but the difference is that aspergillus oryzae is grown upon grains and the soybeans, whereas miso has just the grain inoculated. This diversity of substrate fermentation causes in the words of Sandor Katz a “formation of more complicated metabolic compounds, a higher degree of protein hydrolysis and liquefaction, and the production of much sharper and stronger flavor in shoyu than in miso”. Soy sauce is essentially the liquid on top of the bean paste. This fluid appears on the top for 2 reasons:
OnThere is some controversy around consuming soy products, as it is supposed to raise estrogen levels and cause hormonal abnormalities. However, most of the health problems like the antinutrient isoflavones in soybeans can be negated by fermenting them, and many complications arise from consuming the beans raw. All cultures that consume soybeans traditionally ferment the beans first for this reason, to remove saponins and indigestible compounds that inhibit nutrient absorption and irritate the stomach lining. The process of making soy sauce starts with the soybeans: usually they are boiled because they don't cook properly when steamed. Thus, wheat acts as a mediator of moisture, and another source of starch upon which the mold can act upon. In the first stage, the soybeans and toasted wheat are combined with the aspergillus and left to ferment for about 3 days until a mycelium coating has formed around the outside. It is then poured into a salt brine, around 6% and fermented for a minimum of 6 months, and many traditional ferments age from 1-3 years. Soy sauce can also be aged in barrels like alcohol to develop cask flavors, like Bluegrass soy sauce in Kentucky (see above picture) or smoked soy sauce, but it's usually fermented in a large cedar vat called a kioke . According to the book Culinary Treasures of Japan on the role of koji, or inoculated rice in soy sauce: "[E]nzymes from the koji and the naturally occurring yeasts and bacteria slowly breakdown the complex carbohydrates, proteins, and oils of the wheat and soybeans into sweet sugars, aromatic alcohol, and flavorful amino and fatty acids.” The mash that forms is then called moromi, and once all of the shoyu has been extracted from the top layer, it can be sold to farmers as animal feed. On a side note, this is actually a half-decent idea for some of our excess soybean reserves: it's such a huge cash crop, yet a good portion ends up as animal feed, completely unnatural, or soybean oil, which damages the environment in its production methods. Why don't we direct some more of these soybeans towards human consumption rather than feeding cows soybeans? (insert thinking emoji here). Obviously it's not that easy, but just a thought for consideration. Nama shoyu, or raw and unpasteurized shoyu is considered to be the best quality and healthiest type because of its organic molecule and amino acid concentration, as well as the presence of beneficial microbes. However, there are many different kinds of soy sauce outside of Japan as well: in Indonesia, they produce this: Kecap Manis (pronounced ked-chap mahn-iss) is fermented with palm sugar, clove and anise, and then reduced to a sweet and syrupy consistency. In Vietnam and Thailand, there is tuong, made from toasting soybeans first, lacto-fermenting them, and then inoculating with aspergillus. You get the message - China has around 5 or 6 varieties, and don't get me started on Japan: Unfortunately, many of these varieties are produced commercially or replaced by commercial products. Commercial shoyu is manufactured by the acid hydrolysis of defatted soybeans, i.e after they are extracted for oil, and it does not involve fermentation. Acid hydrolysis extracts free amino acids from the proteins by using HCL (hydrochloric acid) and warm temperatures to break down the vegetal matter, then neutralizing the mixture with NACO32-(sodium carbonate). The reaction yields salt, an organic sediment called humin, and hydrolyzed vegetable protein (HVP), which is supposed to taste like meat broth, thanks to the amino acids threonine. Unsurprisingly, the result is less attractive in aroma and flavor because of “the lack of aromatic substances such as esters, alcohols, and carbonyl compounds which are derived from the fermentation process”, according to the Journal of Industrial Microbiology. Some countries use a mix of both processes, but fermentation is the best way to go for flavor. Japan has pushed back against this complete industrialization: according to the Soy Info center, “In 1963 the Japanese Ministry of Agriculture and Forestry ( Norinsho), with the support of the Japanese Shoyu Association, set the first Japanese Agricultural Standards (JAS) for shoyu; fermented shoyu was still allowed to contain up to 80% HVP. By 1964 HVP constituted only 30% of Japan's total shoyu volume and 20% of the total was still semichemical shoyu”. Although Kikkoman and many of the commercial brands are Japanese, traditional fermentation is still the preferred method of preparing soy sauce. This is in part due to the advances made in the 70s:
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