Soap going rancid and I cannot figure out why.

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Jen74

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Hi everyone. So I've been making soap for about two years now. I make my own soap because I'm allergic to SO many things. I have an illness called Mast Cell Activation disease, and I react to lots of chemicals and stuff. The soap I've been making that seems to work for me is made with the following ingredients and I use soapcalc to get the measurements.

Palm oil- 725.75 grams
Palm kernel oil- 181.44 grams
Distilled water - 265.73 grams
Sodium hydroxide - 130.88 grams
Few drops of ROE

I usually make the HP soap . What makes no sense is that I've had times where it's fine, yet the last two batches I've made went rancid within two to three weeks after making them before their even done curing. I don't change anything. I use to think maybe it was humidity so ran a fan and dehumidifier in the room. I always make sure nothing ever gets contaminated and cure them on plastic racks. I get my oils from Soapers choice and my sodium hydroxide from either Belle Chemical or the Lye Guy. I cure them in the spare bedroom. I just don't understand what I'm doing wrong that they go rancid. I've had batches be fine but also quite a few go rancid. They don't get the DOS, but they will start smelling that rancid oil smell. It's not the oils because they smell fine. If anyone has any ideas at all I would greatly appreciate it. I also don't use and aluminum either. I use silicone soap molds and spoons. Also a plastic spoon to dig out the Palm kernel oil as it's always in a solid block. No idea what is causing them to go bad. I literally only make this soap because I have to. I don't know what I'm doing wrong..
 
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How hot is the batter getting during the cook? Unscented soaps can have a certain smell at times, especially if the oils were heated up a lot.

I made a 100% olive oil soap a long time ago and the bars smell like old oil, but that's the nature of the beast.

If they are not actually showing any signs of being off, I would use them
 

Jen74

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How hot is the batter getting during the cook? Unscented soaps can have a certain smell at times, especially if the oils were heated up a lot.

I made a 100% olive oil soap a long time ago and the bars smell like old oil, but that's the nature of the beast.

If they are not actually showing any signs of being off, I would use them
Hi, thank you for your response. The odd thing is that I've made this soap other times where there is no smell really. I cook it for about 45 minutes stirring after every 15 minutes and it is on low heat( I use my crock pot that use for making the soap). I just can't figure it out. I wonder if something chemically goes awry after it has saponified for make it go bad or while it is curing. I am at my wits end with this as I have tried everything.
 

Zany_in_CO

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I cure them in the spare bedroom.
By any chance, is it sunny in there? I cure soap in my guest bedroom too. The only time I had some soaps that went south on me was a few bars sitting in direct sunlight for part of the day.
I just don't understand what I'm doing wrong that they go rancid
I don't understand it either. Everything you wrote sounds A-OK to me. :thumbs: That shouldn't be happening!!! Crossing fingers that someone comes along with an answer.

Cross Fingers.jpg
 

Zany_in_CO

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Palm oil- 725.75 grams
Palm kernel oil- 181.44 grams
Distilled water - 265.73 grams
Sodium hydroxide - 130.88 grams
Few drops of ROE
RECIPE PRINT OUT ATTACHED

HAH! While formulating your recipe it occured to me that you are using hard PKO instead of the flakes, which is what I use. Palm/ PKO are known for the stearic acid settling to the bottom of the bucket. Unless you are melting and stirring every time, to get the stearic fully incorporated before weighing, it's likely that your batches have more or less stearic acid in them.

I'm not sure that would cause rancidity, though. :smallshrug:

REMEDY: As soon as an order arrives, melt all your oils & weigh several batches at a time into a separate bucket for each batch. Add ROE. Store that way until needed.
 

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Jen74

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By any chance, is it sunny in there? I cure soap in my guest bedroom too. The only time I had some soaps that went south on me was a few bars sitting in direct sunlight for part of the day.

I don't understand it either. Everything you wrote sounds A-OK to me. :thumbs: That shouldn't be happening!!! Crossing fingers that someone comes along with an answer.

View attachment 68939
No, there is no sunlight. It's such a mystery why this is happening.
 

Jen74

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RECIPE PRINT OUT ATTACHED

HAH! While formulating your recipe it occured to me that you are using hard PKO instead of the flakes, which is what I use. Palm/ PKO are known for the stearic acid settling to the bottom of the bucket. Unless you are melting and stirring every time, to get the stearic fully incorporated before weighing, it's likely that your batches have more or less stearic acid in them.

I'm not sure that would cause rancidity, though. :smallshrug:

REMEDY: As soon as an order arrives, melt all your oils & weigh several batches at a time into a separate bucket for each batch. Add ROE. Store that way until needed.
The palm kernel oil comes as a big solid block in a box. Maybe I should order a different kind?
 

Jen74

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One possibility is that by putting in a few drops of ROE, rather than weighing it, you are using too much. The usage rate is really, really low - .05% - that is ½ of 1%.

Using more than the recommended amount is known to cause rancidity. Here is an article about that.
Thank you for telling me this. I usually put like two to three tiny drops in. Maybe it's too much? I will have to buy a tiny scale in order to measure it out.
 

Jen74

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You said the oils smell fine, but how old are they really? Did you purchase them very recently?
I bought the palm oil three days prior to making the soap. The palm kernel I bought two weeks prior to making the soapI( I keep the PKO refrigerated).
 

Zany_in_CO

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I just store that one because I do not use as much and read it stays fresher this way.
Well, while that's generally true, I have PKO (flakes) that's over a year old that I will be soaping soon... we shall see how it does... I need to remember to look up the date and get back to you. :)
 

Marsi

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"the last two batches I've made went rancid within two to three weeks after making them before their even done curing. I don't change anything. I use to think maybe it was humidity so ran a fan and dehumidifier in the room. I always make sure nothing ever gets contaminated and cure them on plastic racks."

If this has started happening two years after you began curing in the room, and now more soaps are getting a rancid smell but the early ones didn't, something has changed to cause it.

As a precaution, I would suggest sanitizing the plastic shelving and using clean teatowels underneath the soap to ensure that there is no hidden triggers residing on the shelving itself (this would show up as marks in the soap normally, but it also can't hurt to do).

The superfat (at 3% is not particularly high, so that's not likely to be an issue, unless your lye has gone a bit lumpy - then the lye has taken on a bit of water from the atmosphere and may not be as strong as it was ... this can increase the superfat without being obvious).

Another thought is to decrease your water, by increasing your lye concentration to around 36% ... less evaporation means less water in the air in the room.

If you can open a window during the day, that might help a little too.

Check for any black mold in the room - look in dark areas around floor level and cupboards - if that is in the room, the spores can trigger dos too.

Other than that, try curing in an alternative space, to see if the room itself is the problem.
 

Jen74

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"the last two batches I've made went rancid within two to three weeks after making them before their even done curing. I don't change anything. I use to think maybe it was humidity so ran a fan and dehumidifier in the room. I always make sure nothing ever gets contaminated and cure them on plastic racks."

If this has started happening two years after you began curing in the room, and now more soaps are getting a rancid smell but the early ones didn't, something has changed to cause it.

As a precaution, I would suggest sanitizing the plastic shelving and using clean teatowels underneath the soap to ensure that there is no hidden triggers residing on the shelving itself (this would show up as marks in the soap normally, but it also can't hurt to do).

The superfat (at 3% is not particularly high, so that's not likely to be an issue, unless your lye has gone a bit lumpy - then the lye has taken on a bit of water from the atmosphere and may not be as strong as it was ... this can increase the superfat without being obvious).

Another thought is to decrease your water, by increasing your lye concentration to around 36% ... less evaporation means less water in the air in the room.

If you can open a window during the day, that might help a little too.

Check for any black mold in the room - look in dark areas around floor level and cupboards - if that is in the room, the spores can trigger dos too.

Other than that, try curing in an alternative space, to see if the room itself is the problem.
Thank you for the advice,I appreciate it. Actually this is a different room I am curing them in. We moved recently, so different house altogether. Is it okay to open windows? I always read that you want the room to be closed up where no outdoor air can get on the soap. I am so confused by it all. I will definitely keep an eye on the lye. I have had in the past where I bought some lye and it was clumoy, I threw that out and did not use it. So far the lye I use seems to okay for the most part. Thank you for the suggestion on using the teatowels. I was using parchment paper to line my racks. Maybe that is not a good idea? The room does not have any mold that I can see or smell so I don't think it would be that. That is a really good idea with increasing the lye. That might help. Thank you so much for the advice. I am just trying to figure this all out. What is interesting is that I do not see the DOS. The soaps start smelling rancid and there is no evidence of DOS usually on any of the soap that I can see. I have seen it happen a little on a couple bars, but that is like weeks after it has started smelling rancid. Usually there is no DOS, just the rancid smell.
 
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Zany_in_CO

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The soaps start smelling rancid and there is no evidence of DOS
Hmmm. 🤔 The plot thickens...

I'm wondering if you have others around that agree that the soaps "smell rancid"? Just a thought. With so many issues addressed properly, maybe your nose is off? :smallshrug:
 

Jen74

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Hmmm. 🤔 The plot thickens...

I'm wondering if you have others around that agree that the soaps "smell rancid"? Just a thought. With so many issues addressed properly, maybe your nose is off? :smallshrug:
Lol, I thought the same thing and had my husband and my dad smell them. They both agree that they smell like rancid oil. I swear if this was not so aggravating it would be laughable. It is odd because the rancid oil smell comes first and then maybe two to three weeks later you will be able to sometimes see a few orange spots, but not on all of the bars. But they all have that smell and the smell gets stronger as time goes on.
 
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