Thread: Tallow based soaps going rancid

Originally Posted by BobH

Thanks for all the replies and enlightenment. I am going to carry on not worrying about it as it seems there is a remote outside chance of that happening under normal conditions.

Bob

I don't think it is that remote for a tallow based soap to go rancid. I have some which went rancid in less than one year and others which are still in excellent condition. I guess it depends on how the soap was made. Like rightly pointed out by Tack, being made of organic materials, it degrades through the exposition of oxygen and sunlight. The rule of 10°C is significant in this case and that's why some soaps can benefit from being kept in a fridge.
Not all the soaps are the same and not all are made the same. All of the non saponified fats and oils, as well as any oil/fat added to the soap at the end of saponification can go rancid even after few weeks.