The history of soy sauce is a bit like the sauce itself, kind of murky. What is consistent is that the precursor to soy sauce is something called jiang. Jiang was a method of preservation popular with the prehistoric people of Asia involving preserving meat and fish with salt. This process produced a bi-product, a salty liquid leeched from the meat that was used to season other foods. This seasoning was developed in China and originally involved many forms of protein: meat, fish and vegetable. Here’s one bit of murkiness, some claim given the difficulty of obtaining meat and fish, vegetable became the predominate protein source and eventually soybeans were selected as the ingredient of choice, and soy sauce was made. While others place the selection on soy as a result of the increased popularity of Buddhism in the sixth century that added vegetarian restrictions to the diet. Regardless, the Chinese have relied on soybeans as a food source for at least 5 millennia. Soy was called Ta Teou, or “big bean”, and declared one of the five sacred grains, along with rice, wheat, barley, and millet. Nutritionally, soybeans provide a healthy and inexpensive source of protein – two pounds of soy flour contains approximately the same amount of protein as five pounds of meat.
A modification to murky idea #1 was proposed by Mark Kurlansky in his book: Salt, A World History which essentially states that soy sauce owes its existance to fish sauce. The Chinese added soybeans to ferment with the fish and that over time they assumed a greater proportion in the sauce until they replaced the fish entirely. At that point jiang became jiangyou. As fish sauce became an increasingly popular condiment in China, oh about 2,500 years ago, the population farther in-land naturally wanted to enjoy this special sauce on their table. The problem was that the farther inland the cook went, the harder fish were to acquire, so like any thrifty cook, they began substituting other ingredients, and by trial and error chose soy beans. The ratio increased in soybeans favor the farther the cook was from the ocean until it completely replaced the fish. Et voila, soy sauce was made.
Regardless of its somewhat questionable provenance, soy sauce is a staple in kitchens around the world prized for the umami flavor it imparts. From China it spread to other parts of Asia and soon reached global popularity. As the sauce became invaluable in the new respective kitchens, the recipes were tweaked to account for local tastes – color, viscosity, level of saltiness, sweetness. Today, cooks well versed in cooking with soy sauce keep multiple jars handy depending on what they are cooking. Chowhound has a discussion board where cooks pipe up on their favorite brands.
How Soy Sauce Is Made Today
Soy sauces are made by mixing either grains, soybeans or some combination of the two with yeast. Traditionally, soy sauces were fermented under natural conditions, such as in giant urns and under the sun (much like fish sauce), for several months which was believed to contribute additional flavours. However, today, most commercially produced soy sauces are fermented under laboratory like conditions, with loads of machinery involved. As you might imagine, this mechanized process significantly reduces manufacturing time with the help of chemical hydrolization and the addition of previously missing ingredients: corn syrup, caramel coloring, to name a few. Side by side, these new products lack the savory flavor and complexity of the traditional soy sauces, and often leave a metallic after taste.
The Manufacturing Process
Traditional brewed method
Brewing, the traditional method of making soy sauce, consists of three steps:
- brine fermentation
Soybeans and wheat are crushed and blended together under controlled conditions. Water is added to the mixture and boiled until the grains are thoroughly cooked and softened. The mash, as it is known, is then cooled to about 80°F (27°C) before a seed mold (Aspergillus) is added. The mixture matures for three days in large perforated vats through which air is circulated. This resulting culture of soy, wheat, and mold is known as koji.
The koji is transferred to fermentation tanks, where it is mixed with water and salt to produce a new mash called moromi. Lactic acid, bacteria and yeasts are added to promote further fermentation. The moromi mash ferments for several months, during which time the soy and wheat paste turns into a semi-liquid, reddish-brown “mature mash.” This fermentation process creates over 200 different flavor compounds.
After approximately six months of moromi fermentation, the raw soy sauce is separated from the cake of wheat and soy residue by pressing it through layers of filtration cloth. The liquid that emerges is then pasteurized. The pasteurization process serves two purposes: 1. it prolongs the shelf life of the finished product, and 2. it forms additional aromatic and flavor compounds. Finally, the liquid is bottled as soy sauce.
Non-brewed method (chemical hydrolysis)
Instead of fermenting, many manufactures artificially break down the soy proteins by a chemical process known as ‘hydrolysis” because it is much faster – a few days as opposed to several months for brewing, and therefore cheaper.
In this method, soybeans are boiled in hydrochloric acid for 15-20 hours to remove the amino acids. When the maximum amount has been removed, the mixture is cooled, halting the hydrolytic reaction. The amino acid liquid is neutralized with sodium carbonate, pressed through a filter, mixed with active carbon, and purified through filtration. This solution is called “hydrolyzed vegetable protein”. Caramel color, corn syrup, and salt are added to this protein mixture to obtain the desired color and flavor. The mixture is then refined and packaged.
Sauces produced by the chemical method are harsher and lack the desired taste profile compared to the traditionally brewed sauces. The difference in taste occurs because the hydrolysis method tends to be more complete than its fermentation counterpart. This means that almost all the proteins in the non-brewed soy sauce are converted into amino acids, while in the brewed product more of the amino acids stay together as peptides, providing a different flavor. The brewed product also has alcohols, esters, and other compounds which contribute a different aroma and mouth feel.
In addition to the brewed method and the non-brewed method, a semi-brewed method exists which is essentially a hybrid of the two in which hydrolyzed soy proteins are partially fermented with a wheat mixture. This method produces higher quality sauces than straight hydrolysis.
As you might image, the non-brewed soy sauces are considerably cheaper than their more time and labor intensive brethren.
You may be surprised to learn that many soy sauces sold in US grocery stores contain zero soy beans as they are made entirely from fermented wheat. (My bottle of Kikkoman soy sauce was made with a combination of both wheat and soy, with wheat being the greater of the two ingredients.) So people suffering from celiac disease and wheat allergies must be alert so they can monitor the ingredients. Although there are many types of soy sauce, all share the common traits of salty and “earthy” tasting; used to season food while cooking or as a condiment on the table.
I visited my local Asian market and found an aisle lined with soy sauces, and the ingredients were relatively few, some had more preservatives than my liking, but the order of ingredients could not be more different. Some had more soy bean than wheat, others had this order reversed. Some used wheat flour. Wheat was by far the alternative grain of choice. Who knew soy sauce could be so complicated?
Chinese Soy Sauce
Chinese soy sauce is made mostly from soybeans, with some other grains thrown in to smooth out the flavor. In China, this sauce is considered essential it is poured on rice, used for stir-frying and as a dipping sauce. It is used in place of salt. Think about it, when you make a Chinese dish, how often do you use salt? Very little, I bet, as that required saltiness comes from sauces like soy sauce or fish sauce.
The two basic types of soy sauce used in Chinese cooking are light and dark.
Dark soy is aged much longer than light soy, and coupled with the addition of molasses gives it a brownish-black color, and more viscous texture. Dark soy is used in cooking as the heat helps develop its flavor and is used in braising and basting meats. Dark soy sauces is avoided when the color of the dish matters, as it will darken the color – nothing like a monotone plate of unidentifiable something. Of the two types, it is the least used – the light soy sauces is considered more utilitarian. If the dish requires, light soy sauce may be added to thin the dark sauce.
As its name suggests, light soy has a lighter color and a saltier flavor when compared to the dark soy, but it is by no means pale. It is mainly used more in cooking, as the rather pungent odor and darker color of dark soy sauce can ruin the taste or appearance of a dish. The light soy sauce made from the first pressing of the soybeans is called tóuchōu, which is loosely translated as first soy sauce, or referred to as a premium light soy sauce. Touchōu is sold at a premium because, like extra virgin olive oil, the flavor of the first pressing is considered superior. A further refinement comes with an additional classification of light soy sauce, shuānghuáng, which is double-fermented to add further complexity to the flavour. These latter two sauces are more delicate and are usually reserved for dipping.
Ideally, both have a home in the pantry. Variations include such flavors as mushroom and shrimp soy sauces, infused with the flavors of mushrooms and brine shrimp respectively. I found a soy sauce with fish roe that just sounds intriguing. Another type, thick soy sauce is a dark soy sauce thickened with starch and sugar, and often contains MSG. This sauce is not often used in cooking but as a dipping sauce or poured on food as a finish for additional flavor.
According to the About page on Chinese food, the best soy sauces are imported from China (Pearl River Bridge brand is an example) or Hong Kong.
A Japanese Buddhist priest came across this seasoning while studying in China and brought the ideae back to Japan, where he made his own improvements on the recipe. One major change the priest made was to make the paste from a blend of grains, specifically wheat and soy in equal parts. This change mellowed the flavor while enhancing the taste of other foods without overpowering them. By the 17th century this recipe had evolved into something recognizable as the soy sauce we know today.
This evolution occurred primarily as a result of efforts by the wife of a warrior of one of Japan’s premier warlords, Toyotomi Hideyori. In 1615 Hideyori’s castle was overrun by rival troops. His wife, Maki Shige, fled to the village of Noda where she learned the soy brewing process and eventually opened the world’s first commercial soy sauce brewery. [source: answers.com]
The Japanese word “tamari” (a type of soy sauce) is derived from the verb tamaru or “to accumulate”, and refers to the fact that tamari was traditionally the liquid byproduct produced during the fermentation of miso.
Japanese soy sauce or shō-yu (しょうゆ, or 醤油), is divided into 5 main categories depending on differences in their ingredients and method of production. Most Japanese soy sauces include wheat as a primary ingredient, and its the starch from the wheat that lends them a slightly sweeter taste than their Chinese counterparts. They also tend towards an alcoholic sherry flavor, due to the addition of alcohol in the product. Japanese and Chinese soy sauce are not really interchangeable in recipes; the Chinese dark soy sauce comes closest to the Japanese version in flavor.
Even among the Japanese varieties, they are not considered interchangeable, and their use is often regional within Japan.
Koikuchi (濃口) “strong flavor” originates in the Kantō region, its usage eventually spread all over Japan. Over 80% of the Japanese domestic soy sauce production is of koikuchi, and may be considered the typical Japanese soy sauce. It is produced from roughly equal quantities of soybean and wheat. This variety is also called kijōyu (生醤油) or namashōyu (生しょうゆ) when it is not pasteurized. It has a dark brown color, rich flavor, and complex aroma. It has a salt content of 18% and is the work horse of the soy sauce world, used with all the proteins in all manner of preparation.
Usukuchi (淡口) “light flavor” is popular in the Kansai region of Japan, it is both saltier and lighter in color than koikuchi. The lighter color arises from the addition of amazake, a sweet liquid made from fermented rice, or mirin and the wheat used is more lightly roasted than in koikuchi. Also, the increased saltiness is attributed to more salt being added to slow the fermentation. The salt content here, hovers at 19%. This sauce is used in recipes where refined color and a weak flavor are required.
Tamari (たまり) is produced mainly in Japan’s Chūbu region. Tamari is darker in appearance, richer flavour, and thicker in texture than its Japanese counterparts as it contains little or no wheat, so it is popular with people suffering from wheat intolerances. It is the “original” Japanese soy sauce, as its recipe most closely resembles the soy sauce originally introduced to Japan from China. Technically, this variety is known as miso-damari (味噌溜り), as this is the liquid that runs off miso as it matures. This sauce is traditionally produced in only three Japanese prefectures, Aichi, Gifu and Mie. This sauce is almost 100% soy beans, with only a small addition of water added to the fermentation mixture. Tamari is preferred as a condiment rather than a cooking ingredient , and if added to a dish, it is towards the end of the cooking process.
Shiro (白) “white” is a very light colored soy sauce. Compared to tamari, shiro soy sauce uses mostly wheat and little soybean, lending it a light appearance and sweet taste. It is more commonly used in the Kansai region to highlight the appearances of food, for example sashimi.
Saishikomi (再仕込) “twice-brewed”substitutes previously-made koikuchi for the brine normally used in the process. Consequently, it is much darker and more strongly flavored. This type is also known as kanro shoyu (甘露醤油) or “sweet shoyu”.
Shoyu (koikuchi) and light colored shoyu (usukuchi) as sold in Japan by Kikkoman.
Other varieties of Japanese soy sauce include:
Gen’en (減塩) Reduced salt. Some Japanese cooking experts advise against this soy sauce as the salt is commonly replaced by preservatives and other additives.
According to Hiroko Shimbo in her book, The Japanese Kitchen, most Japanese kitchens stock three types of shō-yu: koikuchi, usukuchi, and tamari to accommodate the unique features in taste, color and saltiness. She also advises that a key point to remember when cooking with shō-yu is to add it towards the end of the cooking process to preserve its flavor, color and texture. Also due to its high salt content, adding it towards the end helps prevent the foods from leaching too much of their juices. When stir frying, the shō-yu is added by running it over the heated inside wall of the wok to add a nice caramelized flavor to the dish.
All of these varieties are sold in the marketplace in three different grades according to how they were produced
Honjōzō hōshiki (本醸造 方式) Contains 100% naturally fermented product.
Shinshiki hōshiki (新式 方式) Contains 30-50% naturally fermented product.
Tennen jōzō (天然 醸造) Indicates no added ingredients except alcohol.
All the varieties and grades are sold according to three official levels of quality:
Hyōjun (標準) Standard pasteurized.
Tokkyū (特級) Special quality, not pasteurized.
Tokusen (特選) Premium quality, or limited quantity.
Other terms unrelated to the three official levels of quality:
Hatsuakane (初茜) Refers to industrial grade used for flavoring.
Chōtokusen (超特選) Implies the best.
My friend, Robert-Gilles of Shizuoka Gourment has a great post on Japanese soy sauce here complete with some good photos of the process.
Korean Joseon Ganjang
Korean soy sauce, (called Joseon ganjang, 조선간장) is a byproduct of the production of doenjang (Korean fermented soybean paste). Joseon ganjang, thin and dark brown in color, is made entirely of soy and brine, and has a saltiness that varies according to the producer. Wide scale use of Joseon ganjang has been somewhat superseded by cheaper factory-made Japanese style soy sauce, called waeganjang (hangul: 왜간장/倭간장). According to the 2001 national food consumption survey in Korea, traditional fermented ganjang comprised only 1.4% of soy sauce purchases.
In Indonesia, soy sauce is known as kecap (also ketjap or kicap) (a catchall term for fermented sauces) from which according to one theory the English word “ketchup” is derived. Two main varieties exist: salty and sweet.
Kecap asin is a salty soy sauce, similar to Chinese light soy sauce or Japanese shoyu, but usually somewhat thicker with a stronger flavor. This sauce does not immediately develop its flavor in a dish, so advice I’ve seen states to add a little, wait a few minutes, taste and adjust as necessary.
Kecap manis is a sweet soy sauce with a thick, almost syrupy consistency and a pronounced molasses flavor thanks to the addition of palm sugar. Star anise and garlic are also added to the recipe.
Kecap manis sedang is a medium sweet soy sauce, which has a less thick consistency and saltier taste than Manis.
In Singaporee and Malaysia, soy sauce in general is dòuyóu (豆油); dark soy sauce is called jiàngyóu (醬油) and light soy sauce is jiàngqīng (醬清).
Malaysia, which has language and cultural links with Indonesia, uses the word ‘kicap’ for soy sauce. Kicap is traditionally of two types: kicap lemak and kicap cair. Kicap lemak is similar to kecap manis but with very much less sugar while kicap cair is the Malaysian equivalent of kecap asin.
A type of soy sauce based product popular in the Philippines is called toyo. The flavor of Philippine soy sauce is milder compared to its Asian counterparts—adapted to the Filipino palate and its cuisine. It is thinner in texture and has a saltier taste compared to its Southeast Asian counterparts, much more similar to the Japanese shōyu. It is used as a staple condiment to flavor many cooked dishes and as a marinade during cooking, it is also a table condiment, and is usually mixed and served with kalamansi (a small Asian citrus-lime).
Taiwanese Soy Sauce
The history of soy sauce making in Taiwan can be traced back to the provinces of Fujian and Guangdong in southeastern China. The cultural and political gap between Taiwan and China, a result of the First Sino-Japanese Warr in 1895, when China ceded Taiwan to Japan, brought changes to traditional Chinese soy sauce making in Taiwan. Some of the top Taiwanese makers adopted the more sophisticated Japanese soy sauce making technology and never looked back. Taiwanese soy sauce is perhaps best known for its black bean variant, known, not surprisingly, as black bean soy sauce (黑豆蔭油).
See-ew Khaaw (See-eu Khao) or white soy sauce is also called ‘thin soy sauce’ or ‘light soy sauce’. Don’t confuse this with ‘low sodium’ or a healthier version of light. What they mean is it’s somewhat translucent; not as thick as black soy sauce. Preferred brands seem to be ‘Healthy Boy’ and ‘Boat Brand’ also called Nguan Chiang. The brand with the dragonfly on the label is also tasty.
See-ew Dam is a black soy sauce that is thick and black. It has a different flavor than white soy sauce and is mainly used in Chinese-Thai cooking and marinades.
See-ew Khao Het Hom – Soy Sauce with Mushrooms. The woodsy essence of straw mushrooms is blended with the light, thin soy sauce (see-ew wahn) to make a wonderfully useful condiment. Healthy Boy is the recommended brand.
See-ew Wahn (See-eu wan) is a sweet soy sauce and is both darker and blacker than black soy sauce. Its sweetness comes from a hint of molasses. It might be labeled very informatively: Dark Sweet Soy Sauce. [source: realthairecipes]
Note: Don’t use Chinese or Japanese soy sauce when you cook Thai food. The flavor is totally different. Thanks to Leela at SheShimmers for ensuring that I used the correct Thai words. Leela, also posted on Thai soy sauce and other similar Thai seasoning sauces. She is a font of information on Thai cooking and culture, and if you have not discovered her blog, you are in for a treat.
Vietnamese Xì Dầu
Vietnamese soy sauce is called xì dầu, nước tương, or sometimes simply tương. Nước “water, juice, liquid” + tương, probably from 醬 “jam- or paste-like food, thick sauce”
I’ve only found one brand of Hawaiian Soy Sauce and it was started in 1946 in Kalihi, Hawaii by five Japanese families. According to the company website the term Shoyu is widely accepted in Hawaii to mean soy sauce (generically).
Problems with the Cheap Stuff
Many cheaper brands of soy sauces, popular in Southeast Asia and China, are made from hydrolyzed soy protein instead of brewed from natural bacterial and fungal cultures. As a result they do not have the natural color of authentic soy sauces, and so are typically colored with caramel coloring. They are derogatorily called Chemical Soy Sauce (化學醬油) in Chinese, but despite this name are the most widely used type because they are cheap. They are still useful, but for those accustomed to the naturally brewed product, they are bound to be disappointed. Similar products are sold as “liquid aminos” in health food stores in the US and Canada.
Watch out for artificial soy sauce containing chloropropanols 3-MCPD (3-chloro-1,2-propanediol) as this compound is carcinogenic. Also avoid the bottles containing the unregulated 1,3-DCP (1,3-dichloro-2-propanol) which are minor byproducts of the hydrochloric acid hydrolysis, as it may contribute to other health problems.
Here’s a site that has links detailing some of the health issues