Has anyone on here ever had their soap start smelling rancid while it was curing??

[Jen74]

I posted yesterday and I am still trying to figure this whole thing out with my soaps developing a rancid smell 2 weeks into curing. I am perplexed because I cannot figure out why this is happening. This is the second time it has happened. The first two times I made soap, it came out fine, and I did it the same way. What is odd is that I have the containers of oil I used and they smell fine. The rancidity starts up only after the soap has been curing for two weeks, it starts smelling. I use distilled water, no aluminum, and have them curing in my kitchen area which is the best place( least humid). We run our AC all summer long so it is not super humid in my house at all. I use palm oil and palm kernel oil using the soap calc. Do palm oils go rancid moreso than other oils? Could it be the Lye causing the oils to go rancid. I use Sodium Hydroxide. I am getting really annoyed because this is the second batch I will have to trash because of the rancid smell. Something during the soap making process is making the oils go bad, but what?? Anyone have any clues to help me figure this out? Why did my first two batches come out fine? Only thing I was thinking was I made the first two batches during the winter so was thinking is it something with the humidity? But again, my house is not overly humid. We are between 40-50% humidity. Your thoughts?

 

[Jersey Girl]

Sounds like it could be your oils. How old are they?

 

[Jen74]

Sounds like it could be your oils. How old are they?

They are brand new. I just bought them. The expiration date on the palm kernel oil is 12/2021 and the expiration date on the palm oil is 06/2022. They both smell fine. The rancid smell seems to be developing 2 weeks into the curing. I cannot figure this out..

 

[IrishLass]

Hi Jen- when did you toss out your first soap that this happened to? I ask, because soap can go through a variety of different smells during cure for whatever reason, but then bounce back to smelling perfectly fine after cure. If you tossed it out anytime before 8 weeks or so, chances are very good that you may have tossed out a perfectly good batch of soap......... unless it was also accompanied by the development of orange spots appearing on the soap (DOS), which is the surest sign of true rancidity, in which case it was a good choice to toss it.

Depending on the additives I use in any given batch, my soap during cure has smelled like anything from really bad doggy breath, to hair perm solution, to ammonia, to PlayDoh, to whatever else, etc., etc....., but once all the inside chemical micro-changes slow down towards the end of cure, it starts smelling good again as it should. That's just the nature of lye-based soap. I've learned that time is your soap's best friend. If you find you don't like the way it smells at 2 weeks, just keep waiting......it's far from being done doing its thing yet. If you are patient, 99% of the time it will surprise you in a good way.

For what it's worth, palm oil and palm kernel oils are very shelf-stable oils that do not go rancid quickly. I have used both waaaaaaay past their 'best used by' dates (over 2 years past the date), but they smelled perfectly good in the container and they soaped fine, and the soap has lasted forever without issues.

Lye (whether NaOH of KOH) will not cause your fats to go rancid.


IrishLass

 

[Jen74]

Hi Jen- when did you toss out your first soap that this happened to? I ask, because soap can go through a variety of different smells during cure for whatever reason, but then bounce back to smelling perfectly fine after cure. If you tossed it out anytime before 8 weeks or so, chances are very good that you may have tossed out a perfectly good batch of soap......... unless it was also accompanied by the development of orange spots appearing on the soap (DOS), which is the surest sign of true rancidity, in which case it was a good choice to toss it.

Depending on the additives I use in any given batch, my soap during cure has smelled like anything from really bad doggy breath, to hair perm solution, to ammonia, to PlayDoh, to whatever else, etc., etc....., but once all the inside chemical micro-changes slow down towards the end of cure, it starts smelling good again as it should. That's just the nature of lye-based soap. I've learned that time is your soap's best friend. If you find you don't like the way it smells at 2 weeks, just keep waiting......it's far from being done doing its thing yet. If you are patient, 99% of the time it will surprise you in a good way.

For what it's worth, palm oil and palm kernel oils are very shelf-stable oils that do not go rancid quickly. I have used both waaaaaaay past their 'best used by' dates (over 2 years past the date), but they smelled perfectly good in the container and they soaped fine, and the soap has lasted forever without issues.

Lye (whether NaOH of KOH) will not cause your fats to go rancid.


IrishLass

I have one batch here that has been curing for over 8 weeks and it smells rancid. I do see some orange spots on a few on the bars. Not much, but a couple. The smell seems to get stronger as time goes on. Now the second batch I made two weeks ago smelled okay up until yesterday when I noticed the same slight rancid smell. That is what happened to the last batch. Now last year I made the same exact soap using same ingredients and they were fine, never developed a rancid smell. I made those soaps during the winter though and I wonder if humidity has something to do with it? However, our house is not super humid as we have the AC on all the time. I did however use a different brand PKO since the one I had used in my good batches, well they changed their PKO. I was using an organic PKO by Botanical Beauty which was a nice white color. Well they changed it and the color was more yellow now and softer. IT also has a slight smell to it whereas it did not before. This is why I switched brands and ordered a PKO by Dr. Adorable. Well I used this Dr. Adorable brand in my last two batches that have developed this rancid smell. It is odd because the jar does not have a rancid smell. The rancid smell only comes two weeks into the curing phase. It is like it goes rancid while it is curing. It is so mind boggling...

 

[IrishLass]

Hi Jen......I just read your other thread from yesterday (for future reference, please try to post only one thread regarding the same topic. It will create less confusion ).

Anyway, based on the fact that your soap is now also developing orange spots, I believe that it has gone rancid and should be tossed. Also, based on what forum member linne1gi said in her post in your other thread in regards to Dr. Adorable's PKO, I am thinking that it's probably a good bet the problem stems from the PKO bought from Dr. Adorable, since she had rancidity issues with that brand, too. It may very well be that the contamination happened on their end during the extraction process, as Gemstone pony surmised, or even during the packing process.

In any case, I would toss Dr. Adorable's PKO and look for a new source of PKO. For what its worth, I've bought mine from Columbus Foods/Soapers Choice. All of their oils/fats are top-notch quality. It's their PKO that I've used way past the 'best used by' date without issue. I buy the the flaked form of their PKO, and it is white. And I've also bought it from Wholesale Supplies Plus, which has soaped well for me without issue as well.


IrishLass

 

[Jen74]

Hi Jen......I just read your other thread from yesterday (for future reference, please try to post only one thread regarding the same topic. It will create less confusion ).

Anyway, based on the fact that your soap is now also developing orange spots, I believe that it has gone rancid and should be tossed. Also, based on what forum member linne1gi said in her post in your other thread in regards to Dr. Adorable's PKO, I am thinking that it's probably a good bet the problem stems from the PKO bought from Dr. Adorable, since she had rancidity issues with that brand, too. It may very well be that the contamination happened on their end during the extraction process, as Gemstone pony surmised, or even during the packing process.

In any case, I would toss Dr. Adorable's PKO and look for a new source of PKO. For what its worth, I've bought mine from Columbus Foods/Soapers Choice. All of their oils/fats are top-notch quality. It's their PKO that I've used way past the 'best used by' date without issue. I buy the the flaked form of their PKO, and it is white. And I've also bought it from Wholesale Supplies Plus, which has soaped well for me without issue as well.


IrishLass

Thank you so much for the advice and info. I agree, I am going to try a different brand PKO. I will definitely check out the place you mentioned! Hopefully that is the issue. I mean it makes sense since this has happened twice with their product. I appreciate the help.