Does the oyster sauce go bad?

Have you ever bought a bottle of oyster sauce for a recipe that called for it? Half a year later, the sauce is still in the fridge. Does the oyster sauce go bad?

Or maybe it’s your first time using oyster sauce, and you’re not sure if you need to refrigerate it after opening it or not.

If either of these sounds familiar to you, you’re in the right place. In this article, we’ll go over storage, keeping, and shelf life for this thick brown sauce that’s often used in Asian-style dishes. Let’s dive right in.

How to preserve oyster sauce

You are probably familiar with condiments such as soy sauce or vinegar, which do not require refrigeration after opening. Well, oyster sauce is not exactly the same, but let’s not get ahead of ourselves.

To begin with, you should store unopened oyster sauce in a cool, dark place (GD). A cabinet in the kitchen or a shelf in the pantry will do.

Now for the tricky part: does oyster sauce need to be refrigerated after opening? The best answer I can give you is: probably yes.

Golden Dragon Sauces says on their website that refrigeration is recommended, but not required (GD). The cold temperature simply helps to preserve the quality of the seasoning for longer.

Other brands, like the popular Maekrua, stick a large “refrigerate after opening” label on the bottle. That makes it pretty clear that you should keep the sauce in the fridge.

INFORMATION
Oyster sauce and fish sauce are not the same product. Here’s how long the fish sauce lasts.

In general, oyster sauce will not go bad if you leave it open at room temperature for a couple of days, or even weeks. But the quality will degrade much faster, so unless you plan to finish the bottle soon, it’s best to refrigerate it.

How long does oyster sauce last?

The shelf life of this viscous sauce made with oyster extract is highly dependent on the producer and quality. As with many other things in life, the better the quality, the longer it lasts.

Oyster sauces usually have an expiration date of about 18 to 24 months unopened (GD, FK), and the figures are quite similar in all cases. You can find out how long yours should be by looking for the expiration date on the label. Quality comes into play when you first open the bottle.

How long does oyster sauce keep once opened? The FoodKeeper app says you should finish the bottle within three to six months (FK), and that’s enough for just about every oyster sauce out there.

If yours is one of the high-quality ones, it should retain quality for much longer, up to a year, or even longer (GD).

In short, if you are not sure about the quality of the sauce, try to finish the bottle before half a year to get the best flavor.

	Pantry	refrigerator
Oyster sauce (unopened)	Expiration + 3 – 6 months to obtain the best quality
Oyster sauce (open)		3 – 6 months for best quality

Please note that the timeframes above are estimates only.

How do you know if the oyster sauce is bad?

You probably know that distinguishing bad sauces from those that are safe to eat is often difficult. Of course, there are some sure signs that your oyster sauce is bad, like white or green fuzz on the surface or an unpleasant odor. But often things are not as clear as we would like.

Oyster sauce darkens and its flavor gets stronger over time. If it is too strong for your taste, and it is not enough to use less sauce in your dishes, feel free to discard it. Granted, the sauce isn’t bad by any means, but it’s pretty useless, so there’s no point in keeping it.

Another thing worth knowing is that the sauce is thickened in the production process, often using cornstarch (WIKI). And if there comes a point where the water starts to separate on the surface, that means the seasoning is old. And stirring it well (as you do with yogurt) won’t fix the texture problem. If so, get rid of it.