I ran a (very unscientific) poll on Twitter, asking people if they refrigerate soy sauce. Nearly 60 percent of the almost 900 respondents said that they refrigerate this condiment.
That answer isn’t surprising, given that all the soy sauce bottles I’ve seen recommend refrigeration. I used to refrigerate soy sauce, too—until I married into an Asian-American family. My spouse never puts the stuff in the fridge. I later learned that several friends agreed. They insisted that soy sauce refrigeration is unnecessary.
So what’s the deal? Do you really need to refrigerate soy sauce?
No, soy sauce doesn’t need refrigeration after opening. It is high in sodium and fermented, which helps to keep it shelf stable. However, refrigeration can help preserve the flavor if you expect to keep an open bottle for a while, like more than a year.
Take it from Kikkoman, a Japanese brand whose soy sauce bottles are ubiquitous in the United States. The company says that once open, “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. 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.”
We don’t refrigerate soy sauce in my home because we go through it pretty quickly. In addition to using it in Asian recipes, it’s a convenient way to add a salty, umami flavor to other dishes. For example, I regularly add a dash to my tomato sauces. But if you use soy sauce infrequently, it’s probably best to buy it in a small container and keep it in the fridge to maximize freshness.