Pantry and shelf-stable reference

Does fish sauce need to be refrigerated after opening?

No, it does not have to be. Red Boat recommends refrigerating an opened bottle for freshness but states plainly that keeping it at room temperature will not harm the sauce.

Unopened and opened

A shelf-stable package has two different lives, and only one of them is printed on the label. These are the windows Red Boat Fish Sauce FAQs publishes, in its own units. Where it publishes none, this page says so rather than filling the gap.

Unopened: Best-by date about 36 months from the date of manufacture
After opening: Use within about a year
Where to keep it once open: Pantry or cupboard. Refrigeration is optional here, and usually buys quality.

How to use this window

The after-opening window runs from the day the package was opened, not from the date printed on it, so that date is only useful if you wrote it down. Well Stockd does not know when this package was made, bought or opened: record the opened date, follow the package directions, keep your refrigerator at 40°F or below, and use the official item listing when food safety is in question.

Primary sources and limits

The windows above are quoted from Red Boat Fish Sauce FAQs. Storage times are guidelines: quality varies with packaging, temperature, and how the jar is handled between uses. Nothing here overrides a package instruction that says to refrigerate.