I guess the following info explains that this may be typical, but not ideal.
The flavor of this oil is surprising, in effect rather like fish sauce without the salt. This may be because of the large amount of Omega 3, similar to the high Omega 3 content of fish oil . . .
You will know if your perilla seed oil has gone bad if it has darkened in color or has a strange smell or taste . . .
The study was focused on processing of ubi cup cake fortified with omega-3.
The ubi cup cake fortified with omega-3 possessed a slightly pronounced fish odor and fish flavor . . .
In the early developing stage of Designer Egg, an off-flavor (fish-taint) from eggs enriched with omega-3 PUFAs was experienced. It was suspect that the fish flavor generation could be the result of rancidity of omega-3 fatty acids either in feeds and/or animal products . . .
Flaxseed oil smells “fishy” for the exact same reason that fish produces such a smell. In both cases the culprit is the chemical breakdown of a group of compounds called omega-3 fatty acids. This result is rather unfortunate since it is exactly these fatty acids that seem to give rise to the health benefits associated with these oils. However as anyone who has taken such supplements knows, over time these oils also have a tendency to become rancid. On a chemical level what is going on is that the acids become oxidized, creating byproducts that produce the tell-tale fishy smell . . .
It must be hard to tell if fish oil is rancid then . . .
It sounds like people usually go with the rancid fish oil and think that’s normal (scientists included) . . .
For me it’s beginner’s luck I guess (since the perilla oil was on sale), and maybe this will save me the trouble of buying a case, only to find out later on that all of the bottles went rancid. Well I don’t plan on buying any more omega-3 oils now, but would continue to do so on an individual basis, instead of in bulk for sure.