Can You Still Cook With Expired Fish Sauce?
Cooking with fish sauce is not done nearly enough in Western cultures. East Asian and Southeast Asian cultures, on the other hand, understand what a powerhouse ingredient this umami condiment is and the many delicious ways to use it. But for those who don't go through bottles quite as quickly, especially since a little of this pungent liquid goes a long way, there's always a possibility of it expiring before it's used up. Don't be too hindered by that "best before" date, though, as it's generally safe to use even afterward.
Fish sauce undergoes a fermentation process that involves using a lot of salt. The high amount of sodium not only creates the bold, savory taste fish sauce is known for, but it also prevents the growth of bacteria. In turn, the condiment doesn't go bad as quickly and is typically fine to use past the date specified on its label. You can usually make use of fish sauce for two to three years and oftentimes longer if stored in the fridge or a cool, dark place like the pantry.
Signs your fish sauce is past its prime
True as it is that fish sauce is a shelf-stable product, it's still best to be aware of the signs that you'd be better off just getting a new bottle. For starters, fish sauce is already characterized by its strong and, well, fishy aroma. If it becomes rancid or sour-smelling, however, it's safer to avoid using it. You can also tell the condiment's quality has diminished based on its color. A reddish-brown hue is normal, so the liquid becoming significantly darker or cloudy is a reason for concern. A slimy texture is a sign to toss the stuff out, too.
These are all good reasons to replace your current supply of fish sauce with a fresher product. But if the condiment has only slightly deviated from its original qualities, it can still be good for use in recipes with other complex flavors, such as irresistibly savory fried rice. The plethora of other ingredients will meld better with the fish sauce's altered characteristics, as opposed to if the sauce were being used as a stand-alone dipping sauce.