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Does Soy Sauce Need to Be Refrigerated?

Lately, I’ve been using her kitchen more and more to prepare meals. Recently, I made fried rice as a side dish and asked her for soy sauce. Well, she pulled a bottle of soy sauce from the cabinet that looked to be from the 1960s, and when I opened it, the smell was overpowering! It tasted alright, so I went ahead and used it but started wondering just how long soy sauce lasts without refrigeration. It tasted okay, and we didn’t die from food poisoning, but I decided some research was needed.

So does soy sauce have to be refrigerated after opening? No, soy sauce does not have to be refrigerated after opening. Even though the product labels all say to refrigerate after opening, soy sauce contains sufficient amounts of salt, which is a natural preservative and is fermented, which makes soy sauce safe to leave unrefrigerated after opening.

However, the smell, taste, and color will remain unchanged for an extended period of time if refrigerated. Also, I must add that if not refrigerated, soy sauce should be kept in a cool, dry area such as a pantry or cabinet. Soy sauce should be at its peak condition for at least one year after opening if unrefrigerated and two years if refrigerated. Here is the shelf life of a few common types of soy sauce:

Type (Can be 2-10)Shelf Life In FridgeTable Shelf Life
Regular Soy Sauce2 Years1 Year
Low Sodium Soy Sauce1 YearDo not leave out
Dark Soy Sauce1 YearDo not leave out
Thick Soy Sauce1 YearDo not leave out
Mushroom-Flavored Soy Sauce1 YearDo not leave out
Shrimp-Flavored Soy Sauce1 YearDo not leave out
Indonesian Kecap Manis1 YearDo not leave out
Japanese Tamari1 YearDo not leave out

Now let’s explore the subject in greater detail.

How Long Does Soy Sauce Last Once Opened?

How long soy sauce lasts depends on many things, including the ingredients, how it was processed, and how it is stored, before and after the bottle is opened.

Here are recommendations for how long soy sauce lasts after opening with refrigeration and without:

  • Most common type: Lasts 2 years when refrigerated, one year when not refrigerated.
  • All other types: Last one year, when refrigerated and should not be left unrefrigerated after opening.

How to Tell If Soy Sauce Has Gone Bad

Even though the Kikkoman website states that “As long as no water or other ingredients have been added to the soy sauce, it would not spoil if it had not been refrigerated,” they also state that “Once opened, the soy sauce will start to lose its freshness, and the flavor will begin to change. By refrigerating the sauce, the flavor and quality will remain at their peak for a longer period.” We can, therefore, deduce from this statement that the following could happen over time if we do not refrigerate our bottle of soy sauce.

  • The soy sauce will take on a stronger alcoholic odor.
  • The taste of the soy sauce will begin to change and become sharper.
  • The quality and overall appearance of the product will begin to change.

What makes certain types go bad faster, which makes them keep longer, etc.

The regular type of soy sauce is the most reliable as far as maintaining its freshness, taste, and overall appearance. Other types of soy sauce do not have the combination of those four main ingredients of soybeans, wheat, salt, and water, which along with the fermentation process, renders the “regular” kind shelf-stable after opening for an extended period of time.

The addition to or deletion from those four key ingredients and a change in the fermentation process make other types of soy sauce not so reliable and could allow them to lose their freshness faster. The answer here would be to refrigerate all other types of soy sauce after opening to keep them fresh longer.

Things That Help Soy Sauce Last Longer

Here are some common-sense practices that can help to keep your soy sauce good for a longer period of time:

  • Store the unopened bottle in a cool, dark, and dry area such as a pantry or cabinet that is away from any light or heat source.
  • Refrigerate after opening if you do not expect to use the entire bottle within one year.
  • Once refrigerated, continue to keep it refrigerated.
  • If not refrigerated after opening:
    • Keep the bottle lidded to avoid airborne contamination.
    • Avoid cross-contamination with other food.
    • Keep the outside and rim of the bottle and the lid clean to avoid contamination.
    • Store the bottle in a cool, dry place such as a pantry or cabinet and not on a countertop or tabletop where it may come into contact with a bright light, a heat source such as the stove, or direct sunlight.

What to do if You Have too Many Opened Bottles of Soy Sauce

If you find you have several bottles of soy sauce that have been opened:

  1. If unrefrigerated, immediately put extra open bottles into the refrigerator.
  2. Make it a point to serve dishes that contain soy sauce more often until the excess is used up.

Types of soy sauce that would not be safe ever to leave unrefrigerated

Any soy sauce except for the kind that most Americans know as “regular” soy sauce, which is made from soybeans, wheat, salt, and water, should be refrigerated after opening. This “regular” soy sauce is also known as “light” or “thin” soy sauce. The other types of soy sauce include:

  • Low sodium soy sauce which contains up to 40% less sodium than regular soy sauce.
  • Dark soy sauce is fermented longer than light and has caramel and/or molasses added.
  • Mushroom-flavored soy sauce, which is a dark soy sauce that has been infused with dried straw mushrooms or dried Chinese black mushrooms.
  • Thick soy sauce that is often called soy paste or soy jam that is sweeter and thicker than regular soy sauce.
  • Shrimp-flavored soy sauce that is infused with the brine from dried prawns.
  • Indonesian Kecap Mantis which is a thick and very sweet soy sauce made with fermented soybeans and a variety of sugar and spices, including palm sugar, star anise, and garlic.
  • Japanese Tamari is a by-product of making miso and is thicker than regular soy sauce. This type of soy sauce contains little or no wheat and can be considered gluten-free and suitable for use in a gluten-free diet.

Interesting facts about the product and a brief history

Soy sauce, as we know it, was created by the Chinese during the Western Han dynasty (206 BC – 220 AD) and soon spread throughout Southeast Asia as a way of stretching their salt supply for their cooking because salt was at that time a precious and expensive commodity. Japan and Korea each had their own versions of fish-based soy sauce. Still, the soybean-based version became more popular and eventually spread into Europe with the early trade routes, and there is written evidence that soy sauce was being shipped into Europe in the 1700s.

Samuel Wells Williams, who was a missionary and an expert on Chinese culture, wrote that in China, the best soy sauce is “made by boiling beans soft, adding an equal quantity of wheat or barley, and leaving the mass to ferment; a portion of salt and three times as much water are afterward put in, and the whole compound left for two or three months when the liquid is pressed and strained.”

Soy sauce was first produced in the United States in 1908 in Hawaii, which at that time was a territory of the U.S. and not yet a state.

Studies have shown that Chinese dark soy sauce has ten times the antioxidants of red wine, and allergic reactions to soy sauce are rare.

Final Thoughts

In 2008, Kikkoman started printing “Best By” dates on their retail supermarket items, and according to the information on their website, Kikkoman soy sauce is good for at least two years past the “Best By” date. So, any bottle of Kikkoman soy sauce that does not have the “Best By” date on the label, you can assume is an older bottle that should be discarded immediately.

Since the bottle of soy sauce, unlike other condiments in my sister’s kitchen definitely does not have a “Best By” date on the label, I’m going to take it upon myself to discard that bottle and replace it immediately even though the information from Kikkoman also states that soy sauce doesn’t actually go bad, but the quality and taste change over time. That’s enough for me, and I want only the best tasting soy sauce to use on my food.