- How to tell when a fat or oil is rancid? Does the taste provide a clue?
I have often been in the situation of tasting something, such as a walnut or some fish oil, that just didn't taste right - a sort of strong "stale" flavour - so there is now a type of taste that I intuitively associate with rancidity. I've noticed it in nuts, fish oil, butter and tallow that had been kept for a while in the fridge. But I'm not sure if I've correctly identified it... (sometimes I wonder if it's just natural variation in the flavour of foods from different origins) and I guess that sometimes fats can be rancid without their taste being noticeably affected.
I'm curious to know if other people have identified a type of taste they associate with rancidity, and if anyone wants to have a go at describing it (which I realise is difficult) that would be really helpful.
- Also, am I right in thinking that when coming across something potentially rancid, the best course of action is to not eat it (because doing so might do more harm than good)?
asked byarchaea (2254)
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on February 26, 2010
at 06:56 PM
It seems to be mostly undetectable to the human tongue, except in the worst cases. I wrote a post about it. Fresh nuts taste better to me, but the average grocery store probably-rancid nut tastes fine.
With whole foods like fish it is easier, but I do worry about canned fish myself as I eat it often. I looked up studies on the subject, but there weren't many. With a refined oil it's harder to detect rancidity by taste. And some people like the taste From "Consumer acceptance of canola oils during temperature-accelerated storage" about canola oil "Anecdotal evidence that people like the taste of some oxidized lipids has raised concern "
The info about rancidity and taste is unfortunately in Oxidized Fat in the Diet by Jeffrey S. Cohn which you have to pay to access. Back when I read it I had academic accessIt's also talked about in the excellent cookbook Fat by Jennifer McLagan when she talks about how refined oils are a bad choice. It's true. When my lard is bad it's pretty obvious, but my roommate's 2 year old canola oil doesn't smell like anything. One of my food science textbooks expressed concern at how some oil processors remove odors that would indicate rancidity to consumers.
on February 27, 2010
at 04:43 AM
If you want to familiarize yourself with the aroma (taste if you dare) of rancid oil, go buy a can of linseed oil (paint section) from the hardware store. That is industrial flaxseed oil that has undergone considerable heat and processing.