Does soy sauce expire?
Still tasty implicitly says that the sauce stays indefinitely technically edible. The expiration date is only for quality purposes. I think the sauce probably doesn't have an expiration date but rather a "Best By" or "Best if Used By" date.


  
  Storage time shown is for best quality only — after that, the sauce's texture, color or flavor may change, but in most cases, it
  will still be safe to consume if it has been stored properly.
  If sauce develops an off odor, flavor or appearance, it should be discarded for quality purposes.