Soy Sauce 101

Written By: Sofia Layarda, MPH

Title: Master of Public Health

Alumni: University of California, Berkeley

Last Updated on:

In June 2012, a Dutch study published in the Food Quality and Preference journal reported that substituting salt with naturally brewed soy sauce can reduce sodium content by one-third without compromising taste. How is this possible, when most of us equate soy sauce with high sodium?

Soy Sauce 101: Not All Soy Sauces are Created Equal

There is no doubt that soy sauce is a high-sodium product. However, the naturally brewed varieties have much higher flavor intensity and complexity; you won’t need as much to achieve a flavor “hit.” From personal experience, I can tell you that naturally brewed soy sauce also changes flavor when cooked, while non-brewed soy sauce tends to stay the same salty flavor.

Soy Sauce 101 Poster

Naturally brewed soy sauce is actually the liquid resulting from a boiled, mashed, fermented, and aged mash of soybeans, sometimes with added wheat. The culture used for fermentation is a mold, and sometimes bacteria and yeast. The aging process can take months or even years; unfortunately, many cheaper modern soy sauces are no longer made this way. Instead, salt, hydrolyzed soy protein, flavorings and/or colorings are mixed together to create a dark sauce that approximates the saltiness, but none of the flavors, of traditionally brewed soy sauce. We even discovered a soy sauce packet from a Japanese takeout restaurant that contains high fructose corn syrup and caramel coloring!

Types of Traditional Soy Sauce

East Asian households often have several kinds of soy sauce as pantry staples. There are several types of traditionally brewed soy sauce:

  • Dark: These soy sauces tend to be almost black in color and very aromatic, don’t taste as salty, and have a thin viscosity. They are typically made with equal amounts of wheat and soy. Some Chinese brands use minimal amounts of wheat.
  • Light:  The term “light” only refers to the color of the sauce, not sodium level or calories. They have the most direct salty “hit.” They tend to contain more wheat than soy. Most Asians routinely use light soy sauce in their cooking. If you need to watch your sodium levels, you may look for “light-salted” soy sauce.
  • Tamari: There is some confusion surrounding the term “tamari”; although some tamari soy sauces are gluten-free, many contain wheat. Look for “wheat” or “soy sauce” (which contains wheat) on the ingredient list. If you are looking specifically for gluten-free soy sauce, make sure the tamari sauce you are considering actually specifies that it contains absolutely no wheat. Tamari sauces tend to be thicker.
  • Sweet: Sweet soy sauces are found in Southeast Asian cuisine, and they are sweetened with palm sugar or cane sugar. They are very thick, almost the same consistency as molasses, and may have spices added.

What Should You Look For When Buying Soy Sauce?

Whatever brand  you choose, read the ingredients and it should be fairly clear. A naturally brewed or traditionally brewed soy sauce should contain no more than the following ingredients: water, soybeans, maybe wheat, salt, and a starter culture (the mold used to ferment the mash). A genuine, naturally-brewed soy sauce contains no preservatives; therefore it should be refrigerated once it’s open.  If the bottle of soy sauce you are checking out contains hydrolyzed soy protein, artificial colorings, artificial flavorings, or other thickeners, put it back on the shelf.

The Bottom Line

For condiments and processed sauces, label reading is a given in today’s marketplace. Who knew there were so many things to watch out for in something as seemingly simple as soy sauce!

Tell Us: Do you have a favorite soy sauce brand?

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