The source of soy

August 13, 2007 (Last Updated: January 11, 2019)
soy sauce

Soy sauce, thought to be one of the world’s oldest condiments, has been integral to Eastern cooking for 3 000 years. Fx went to a soy tasting at Lynton Hall, the renowned boutique hotel in KwaZulu-Natal


Soya beans can be traced back a remarkable 4 000 years, and Chinese Emperor Shen Nong declared them one of the five sacred crops. It’s no surprise, therefore, that its derivative, soy sauce, also shares a long history. The beginnings of the sauce can be traced back to early Asia when people preserved meat and fish in salt, and the liquid from the meat was then used as a base for broths and seasoning.

During the sixth century Buddhists used the first known product to resemble soy sauce – a vegetarian-friendly salty paste made from fermented grains. The sauce was taken to Japan by a Zen monk who discovered it while studying in China. After returning to Japan he made his own soy sauce, but the ingredients and techniques were ultimately modified by the Japanese.

While China and Japan remain the largest producers and consumers of soy sauce, the advent of fusion food and cross-pollination of cultures have seen it permeate western cuisine. It’s even an ingredient in well-known products like Worcestershire sauce. True soy sauce is called shoyu and, by definition, is a salty brown liquid condiment made by fermenting soya beans and roasted wheat or barley in brine. Select soya beans and wheat are blended, a seed mould is added and the mixture matures for three days in perforated vats through which air is circulated. This culture called koji is then transferred to fermentation tanks, mixed with brine and allowed to ferment for anything from several months to two years, which creates the distinct nuances of flavour and aroma.

Once fermentation is complete, the raw soy sauce is filtered to remove the solids, then it’s refined and pasteurised. High demand for soy sauce has been responsible for a short cut that shuns the traditional method in favour of an inexpensive chemical variation.

Non-brewed soy sauce is made in just days using roasted soy meal and hydrolysed vegetable protein, and some non-brewed soy sauces have been found to contain possibly carcinogenic substances (chloropropanols). We are all familiar with the four basic flavours of sweet, salt, sour and bitter but Kikkoman, one of the world’s largest producers, talks about soy sauce containing the elusive umami. It can be translated from Japanese as delicious, savoury or brothy, and refers to a synergy of intricate, balanced flavours.

In soy sauce, umami results from more than 285 flavour and aroma components and a high concentration of amino acids that trigger taste receptors on your tongue. Umami, the elusive fifth flavour, is indeed the holy grail of soy sauce.

Boutique hotel, Lynton Hall on the KwaZulu-Natal south coast, provided the rendezvous point for the rather quirky event of soy sauce tasting. Charismatic manager Germain Lehodey has previously delved into the likes of spring water and salt tastings, but this time soy sauce was the subject. A total of 23 locally available sauces were tasted, which had been made in China, South Africa, Thailand, Malaysia, Taiwan, Hong Kong, Australia, Indonesia and Japan. Those that were well balanced, had a lingering aftertaste and were naturally made, emerged as the favourites.

Chinese and Japanese soy sauces are markedly different and can’t be substituted for one another when cooking. Most Chinese soy sauces have a shorter brewing process and a higher salt content.

Chinese sauces contain more soya beans than their Japanese counterparts and the two most widely used are light and dark soy sauce. Light (or fresh) soy sauce is saltier and therefore primarily used for seasoning. The first pressing of the soya beans is called touchõu and, like virgin olive oil, is sold at a premium as it has a superior taste. A dark or “old” soy sauce is aged longer and molasses has been added so it is used mainly for cooking.

The Japanese variations are divided into five main categories according to the ingredients and the technique of fermentation. As wheat is the main ingredient, Japanese soy sauces are sweeter. Koikuchi comprises 80 percent of domestic production so it can be considered the most typical Japanese soy sauce. If it’s not pasteurised it is called namashõyu. Sukuchi is saltier and lighter in colour than koikuchi as the sweet liquid from fermented rice is used in production. Tamari is produced mainly from soya beans, with very little or no wheat, and is dark in appearance and richer in flavour than the others. As it was introduced by the Chinese, tamari is considered the original Japanese soy sauce.

On the other end of the spectrum is shiro, consisting mostly of wheat, which imparts a sweet taste. The last category is for the twice-brewed saishikomi, which uses koikuchi instead of brine, resulting in a sauce that is darker, stronger and sweeter.

Colour, flavour and aroma are all giveaways. Look on the label for natural ingredients: soya beans, wheat, water and salt. Naturally brewed sauces shouldn’t contain colourants or flavour enhancers. The cost of the product should give an indication as to the method employed in making it.

If unopened, soy sauce should be stored in a cool, dark place. Once opened, it should be kept in the fridge. Low-sodium soy sauce should be refrigerated after opening because the low salt content makes it more susceptible to oxidation, which causes the colour to darken and flavour to weaken. A sealed glass bottle of soy sauce will keep for two years in the correct conditions. For maximum taste, soy sauces for table use should be used within a month of opening, while those used for cooking purposes will last for three months.

Yes, and soy sauce can be used in European cuisine. In fact, Kikkoman suggests experimenting by replacing the salt normally used in seafood, meat, vegetables, salad dressings and even pasta sauces with a swirl of light soy sauce. Dark soy sauces are ideal for stews, gravies and red meat. Once added, cream-based sauces will taste nuttier; tomato sauces will be less acidic; batters will be more golden brown; pot roasts will be heartier and sautéed mushrooms will taste meatier. Good to know too is that when you are cooking with soy sauce, it should be added towards the end of the cooking time so it does not dull the colour of your dish. When using soy sauce as a dip, it is a good idea to mix three parts light soy sauce with two parts dark.

A study by the National University of Singapore showed that Chinese dark soy sauce contains 10 times the amount of antioxidants found in red wine. It does contain a small amount of natural-occurring monosodium glutamate (MSG). In 2001 the UK Food Standards Agency tested various soy sauces that weren’t naturally fermented and found that they contained a chemical called 3-MCPD (3-monochloropropane-1,3 diol), which has been linked to cancer, at levels higher than deemed safe by the European Union.

If you’d like to do a home tasting, follow these easy steps.

  1. Some soy sauces can be purchased from your local supermarket but supplement these with a selection from your local Chinese or Japanese speciality shop.
  2. Taste all the soy sauces prior to the tasting to ascertain the correct order they should be tasted in. Move from the lightest in taste to the saltiest. Should you stumble across any particularly bad examples, Germain recommends keeping them until last so as not to “destroy” your palate. Remember to pop the opened sauces into the fridge.
  3. For the tasting, pour a small amount of each sauce into a white saucer and number each correctly.
  4. The tasting is best facilitated with small pieces of steamed chicken breasts as the meat is neutral in taste and allows for easy absorption of the sauce. Use a toothpick to spear a small cube of chicken, and dip it into the appropriate sauce.
  5. Bear in mind that the initial saltiness of the first couple of sauces may take some getting used to. Make allowances for this if scoring each sauce.
  6. When making notes about each soy sauce, take care to ascertain whether it’s well balanced, regardless of how salty it is.
  7. Once you’ve tasted a few soy sauces, you’ll be able to start to identify how each sauce is best used. As a guide, many of the Japanese sauces are used for dipping (think sushi and sashimi) while the Chinese ones are used primarily for cooking. Once the sauces have been revealed and consensus is reached on favourites, it’s interesting to go back and taste again, comparing those that are from different countries, are organic or have less salt.
  8. If the label is in English, take note of the ingredients. Generally the sauces with the highest percentage of soya beans are those favoured for taste.

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