Toss it Michael.Your right that something that is salted and fermented willl last for some time,but not all fish sauces are created equal.Because natural fish sauce requires time to make and very fresh, good quality fish, substantial investment is necessary for large-scale production. This has resulted in the proliferation of a number of less-than-pure products. Some are made by the process of hydrolysis in which some kind of enzyme or acid is added to hasten fermentation, while others are made by diluting natural or hydrolyzed fish sauce with salt water flavored and colored with sugar, caramel, monosodium glutamate (m.s.g.), by-products from the production of m.s.g., saccharin, and other natural or artificial flavorings and coloring.For example three crabs brand according to the label, hydrolyzed wheat protein and fructose are among the ingredients – both are additives that have not been adequately time-tested for their potential long-term effects on health.And it's made in Hong Kong not Thailand,where it says it's a product of.
Look for fish sauce with a clear, reddish brown color, like the color of good whisky or sherry, without any sediments. If the color is a dark or muddy brown, the sauce is likely to be either a lower grade, or one that is not properly or naturally fermented. It may also have been sitting on the shelf a bit too long.
My recomendation is golden boy.
EDIT:Just want to add that grade "A" fish sauce in North America is pretty much non existant,and if anyone has a source I would appreciate it.
It takes 18 months of fermentation to make a really good fish sauce and the good stuff is generally added to lower quality sauce to improve the flavour,so the grade "A" is like gold.
Probably more information than anyone wanted to know,but there it is,I just can't help myself.
