That is sort of like certain of us getting a nasty, rotten-fish taste from canola oil. Odd, because I love nuoc mam, which is made from …
I am VERY suprised that veg oil (usually soya, canola etc) would go rancid only 9 months after its best-before date. Odd.
Depends on how it’s stored too. It’s it’s stored near the stove or oven, the heat can make it go rancid faster.
I don’t use canola oil anymore… so I don’t have a good memory what it tastes like. 
Currently, I use grapeseed, peanut, and olive oil. My grapeseed doesn’t have much taste. Peanut oil definitely has that peanut flavor to it. Olive oil… I can taste the extra virgin olive oil, but the so called “light” olive oil barely has any taste to it.
I try to write a date on stuff when I open, then if I see that the date seems very old I can do a deeper, more suspicious sniff/eyeball.
that’s a great idea – I do it with dried herbs, so I don’t know why I wouldn’t do it with veg oil.
I can smell a slightly fishy aroma when I’m cooking with canola, but I don’t taste it – and family and friends always comment on my sensitive sense of taste (I’m not picky – but having a good sense of taste usually allows me to reverse-engineer an awful lot of favorite restaurant dishes for people with a high degree of success!)
Sonny boy came home again today so I have a chance to redeem myself for this last rancid meal. Easy like Sunday morning!!!
The type of “sick” you’d get from rancid oil is not prompt gastrointestinal suffering. Rancid - that is to say, oxidized - fats contribute to inflammation. Enough long-term consumption can damage the liver and other organs. You know how we’re all supposed to get plenty of anti-oxidant ingredients into our meals? I don’t mean to be harsh but frankly, I’d be more concerned about the lack of fiber and green vegetables in those two meals than the presence of outdated oil. Hopefully this is not typical of your son’s day-to-day food intake.
Because they haven’t seasoned the cast iron properly. If you season it correctly the metal develops a non stick coating and doesn’t react with the food.
It’s also the reason why the French put enamel over cast iron (le Creuset) but if it’s seasoned the right way you don’t need the enamel.
Acidic ingredients such as tomato and wine degrade the seasoning of a naked cast iron pan, allowing the food to taste of iron. This is more noticeable with long-cooked foods than those which cook quickly. Incidentally, if your cast iron has a residual smell/taste from cooked fish, rinse and wipe it out, then place it in a 400F oven for a half hour or so. This will destroy the fish oil that’s the culprit. Some people play it safe by having designated cast iron for different tasks, e.g., one for cornbread, tarte tatin, and the like, and another for meats.
Just got my first cast iron pan, looking forward to cooking a nice rib eye in it. Although my stove has a grill in it, whenever I use it for anything it sets my smoke alarms off. Even with the hood vent on high, the drill does it every single time.
But the presence of rancid oil tastes really, really awful, so will self-fulfill the idea of not consuming it.
Gotta be honest with you, I keep my cast iron well seasoned, clean it carefully, and if it imparts a taste it’s not such that anyone I cook for can notice.
I suspect the culprit for a lot of people is the use of detergents when cleaning which destroys the seasoning.
