Storing groceries in the refrigerator is supposed to keep them fresher longer, right? Not always. Think about fresh basil, which food director Chris Morocco recommends you treat like a bouquet, storing the stems in a cup of water on the counter; or butter, which you can leave out at room temperature.
But what about soy sauce? It doesn’t spoil like milk or wilt like vegetables, and it doesn’t usually grow mold or show any other signs of deterioration. Plus, it’s not refrigerated in grocery stores, so should you follow suit? To understand the answers, it’s important to first know the basics of soy sauce.
How is soy sauce made?
Soy sauce is one of the original condiments. Its origins can be traced to China, approximately 2,500 years ago—long before refrigerators—but over the years it spread across Asia. Countries like Japan and Korea put their own spin on the staple, which is why there are now a huge number of varieties of soy sauce available: koikuchi shoyu, a Japanese dark soy sauce that’s great for marinades and braises; sheng chou, a light Chinese soy sauce relied on for seasoning Cantonese stir-fries and sauces; guk-ganjang, a Korean soy sauce often used in soups (perfect for Miyeokguk); and lots more.
For many of them, including most of the soy sauce in American supermarkets, it all starts with two ingredients: soybeans and wheat. Soybeans are cooked and combined with wheat, mixed with a specific type of mold called Aspergillus oryzae, and left to sit for a few days. Then, goes in salt water and bacteria, like Lactobacillus. The whole thing ferments for a while—the longer the ferment, usually the more expensive the resulting soy sauce—until it’s strained, pasteurized (in most cases), and glugged into the bottles you see at your grocery store.
If you’re avoiding gluten, there are gluten-free optionals available, including tamari, which is made from the liquid collected during miso production. Just check the ingredient list on the label accordingly.
Does soy sauce need to be refrigerated?
So, should you stick your soy sauce next to your mayonnaise and oat milk? The answer depends on a few factors. First and foremost: Consider how quickly you’re burning through your bottles of soy sauce. If you’re reaching for your soy sauce every night for everything from a Shrimp and Asparagus Stir-Fry to Soy-Braised Chicken Legs to Cocoa Brownies (yeah!), you’re more than likely finishing your soy sauce supply faster than it can go bad, even if you’re storing it on the counter. That’s the case for senior test kitchen editor Shilpa Uskokovic, who says that in every restaurant she’s worked in, as well as in the Bon Appétit test kitchen, the soy sauce has always stayed on the counter or in the pantry.
At home, Shilpa opts for an artisanal soy sauce, which she does keep in the refrigerator. That’s because more expensive soy sauces typically lack the preservative, sodium benzoate, that more common grocery-store soy sauces use to extend shelf life. That preservative, as well as soy sauce’s high salt content, mean it’s very difficult, though not impossible, for mold or bacteria to grow in your opened bottle of soy sauce—never say never!
All to say, you probably don’t have to refrigerate your run-of-the-mill grocery-store soy sauce for safety reasons. You still might want to stick it in the fridge to maintain the flavor; soy sauce oxidizes after you open it, but it stays at peak freshness for three to six months once it’s opened. After that, it starts to lose some of its more delicate, nuanced flavor.
Even if you go over the six-month mark, soy sauce is still a flavor powerhouse. While you might not get all those subtleties that are most noticeable upon opening a new bottle (like how it wakes up the dipping sauce for your Pork and Scallion Dumplings With a Crispy Skirt), it’s still a great addition to dishes like Saucy Soy-Butter Beef and Peppers and Sake-and-Soy-Braised Pork Belly, where it can share the spotlight with other ingredients.