Rancid soap??

[Jen74]

Hey everyone,

So I have been making my own soap now for about a year. I use just a few basic ingredients because my skin is Severely sensitive and I react to many things. I got it down to palm oil, palm kernel oil, lye, and water and I use the soap Calc. Those are my ingredients and they work well for me. Last year I noticed my soaps were getting rancid rather quickly and could not figure out why. I switched to making hot process soap and that seemed to help. I also started using a smal fan to blow on them while they are curing over the 4 to 6 weeks. Well everything was going great, no more rancid soap. Well now here in Chicago it is spring and the humidity is up. Well all my soap that I just made a couple months ago went rancid! The only thing that is different is that it seems like in the winter, the soap has no issues( it is also very dry in the house). What can I do to prevent this? I bought a small table top dehumidifier which I will get tomorrow. I am thinking maybe if I place this dehumidifier in the area where I cure the soaps this can help? We have the AC on as well on hot humid days. Should I also use a fan on the soaps along with the dehumidifier? I am at a loss and not sure what to do. I mean I lost like a whole batch of soap because it smells kind of rancid( that old oil smell). I do not think it is safe to use rancid soap right? Any suggestions? Does anyone else use a dehumidifier? Does this prevent soap going rancid?

 

[Johnez]

In addition to humidity there's also the possibility that one of your oils is rancid or that some metal other than stainless steel came in contact with your soap.

 

[Jen74]

In addition to humidity there's also the possibility that one of your oils is rancid or that some metal other than stainless steel came in contact with your soap.

No stainless steel touched it that I know of. The oil smelled okay that we used. In fact we still have some, it smells fine. We have been using a crock pot that is ceramic inside. Never had an issue before with it.

 

[Johnez]

No stainless steel touched it that I know of. The oil smelled okay that we used. In fact we still have some, it smells fine. We have been using a crock pot that is ceramic inside. Never had an issue before with it.

Stainless steel is ok, it won't react with lye. Other metals will react with lye though.

 

[Jen74]

Stainless steel is ok, it won't react with lye. Other metals will react with lye though.

I basically use silicone spoon to stir and my crock pot I cook it in is ceramic. The molds I use are also silicone. When curing I use a plastic table to set them on. I keep them in my living room/kitchen. Our house is not too big so I try and keep it in the driest place. I do not want to keep it the bedroom as the bathroom is in there and I worry about the humidity. Would the small dehumidifier prevent them going rancid?

 

[ResolvableOwl]

Hi @Jen74,
I'm sorry for you and all your issues (and your soaps that went bad).
For a first, be happy that you found a recipe that your body doesn't reject! Funny enough, From a technical soapmaking perspective, it is fortunate that it's of all the “boring base oils” PO and PKO that work for you. Odd that these give you rancidity issues, since they're among the most robust oils of all, and for these reasons used for deep-frying, baking etc., and have a long shelf life to begin with.

You have already addressed some “external” factors like kick-starting curing (fan, dehumidifier, AC), but I suspect there are still “internal” things annoying you. @Johnez pointed on contact with metals, which is important to avoid. Chelators (citrate, EDTA etc.) are powerful agents to avoid “invisible” metal contact (soluble contaminations), and prove as valuable helpers in fight against rancidity. Read up backgrounds and avoiding of rancidity here: Rancidity and DOS | Soapy Stuff
You cannot (and don't need to) get your soaps totally dry. A bit of water is bound very strongly to the natural glycerol. But water is not the main reason for a soap to go rancid. Just like oils can go bad without water, soaps can as well. Protection of the oils is first priority.

Another point is the recipe itself. High-PO soaps aren't very common, since they are very hard and difficult to get any lather off. A bit of PKO will make things only a bit better. What is your lye concentration? What is your superfat? High superfat is a major culprit: free fats/fatty acids foster rancidity.

Another common reason for rancid soap is that the oils themselves had gone bad when you used them. Check your batches, and replace them when in question. Rancid oils make rancid soap.

 

[Jen74]

Hi @Jen74,
I'm sorry for you and all your issues (and your soaps that went bad).
For a first, be happy that you found a recipe that your body doesn't reject! Funny enough, From a technical soapmaking perspective, it is fortunate that it's of all the “boring base oils” PO and PKO that work for you. Odd that these give you rancidity issues, since they're among the most robust oils of all, and for these reasons used for deep-frying, baking etc., and have a long shelf life to begin with.

You have already addressed some “external” factors like kick-starting curing (fan, dehumidifier, AC), but I suspect there are still “internal” things annoying you. @Johnez pointed on contact with metals, which is important to avoid. Chelators (citrate, EDTA etc.) are powerful agents to avoid “invisible” metal contact (soluble contaminations), and prove as valuable helpers in fight against rancidity. Read up backgrounds and avoiding of rancidity here: Rancidity and DOS | Soapy Stuff
You cannot (and don't need to) get your soaps totally dry. A bit of water is bound very strongly to the natural glycerol. But water is not the main reason for a soap to go rancid. Just like oils can go bad without water, soaps can as well. Protection of the oils is first priority.

Another point is the recipe itself. High-PO soaps aren't very common, since they are very hard and difficult to get any lather off. A bit of PKO will make things only a bit better. What is your lye concentration? What is your superfat? High superfat is a major culprit: free fats/fatty acids foster rancidity.

Another common reason for rancid soap is that the oils themselves had gone bad when you used them. Check your batches, and replace them when in question. Rancid oils make rancid soap.

Thanks for the reply. I definitely did not use any metal. I cook mine in a ceramic crock pot, use silicone spoons for stiring and silicone molds. This is the recipe I use from SoapCalc: 9.18 ounces of water, 6.40 ounces of Palm Kernel Oil, 25.60 ounces of Palm oil, 4.52 ounces of lye and 1.6 ounces of Glycerin. What is weird is that I made several batches during the winter that did fine. It seems like when the warmer weather hits, this happens, I even have my AC on most days too when it is hot or humid.. So strange. The oil I used smells okay. Do you have any suggestions? I have not used any additives like EDTA because I am so sensitive to stuff that I try and stay with as little ingredients as possible. Any suggestions?

 

[ResolvableOwl]

That's 33% lye concentation at 5% superfat, with 20% lauric oil, prepared as HP. An absolutely common recipe, except for the extra glycerol, which makes sense to make the final soap bars somewhat easier soluble. Provided that the oils are of decent quality, this should have negligible chances of rancidity, FWIW. The apparent influence of weather just makes it stranger.

But that means that I have little to offer, from the distance, I'm afraid. You could give sodium citrate a chance as a chelator, citrates are very mild (contained in many foods, and a regular metabolism intermediate anyway). You could reduce glycerol a bit and/or swap it for sorbitol or plain table sugar, which makes the soap less keen to pull air moisture, still increase solubility. I guess you are using distilled water for everything?

 

[amd]

I got it down to palm oil, palm kernel oil, lye, and water and I use the soap Calc.

What water do you use? Is it bottled water or from the tap? If bottled water, is it distilled, spring, or drinking water? If from the tap, do you have a water treatment system?

My first soaps that I made, even though I knew better, I used tap water just to make sure. All of those first two batches developed DOS within weeks of curing. I switched to distilled water - spring or drinking water is about the same as tap - and it hasn't been a problem.

 

[Jen74]

What water do you use? Is it bottled water or from the tap? If bottled water, is it distilled, spring, or drinking water? If from the tap, do you have a water treatment system?

My first soaps that I made, even though I knew better, I used tap water just to make sure. All of those first two batches developed DOS within weeks of curing. I switched to distilled water - spring or drinking water is about the same as tap - and it hasn't been a problem.

I use distilled water

 

[lenarenee]

Interesting. The recipe comes out to about 9 for the linolenic and linoleic. (guessing coconut was 20%)

Is the soap curing in a dark place?

Has it been humid enough that you’ve noticed beads of moisture on the soap? That Can bring particles to the soap.

I wonder if lowering the super fat to 2 or 3 will help. You’ll have less free oil in the soap.

Some people think that storing bars in muslin bags helps a lot. So maybe let the soap cure for 4 weeks, then store in muslin, but keep in a dark, dry place with ventilation.

 

[Jen74]

Interesting. The recipe comes out to about 9 for the linolenic and linoleic. (guessing coconut was 20%)

Is the soap curing in a dark place?

Has it been humid enough that you’ve noticed beads of moisture on the soap? That Can bring particles to the soap.

I wonder if lowering the super fat to 2 or 3 will help. You’ll have less free oil in the soap.

Some people think that storing bars in muslin bags helps a lot. So maybe let the soap cure for 4 weeks, then store in muslin, but keep in a dark, dry place with ventilation.

Thanks for the reply. I actually don't use any coconut oil( I'm allergic). I just use palm oil, palm kernel oil, a tiny bit of glycerin, lye and water. How would I go about lowering the superfat ( palm oil) without messing up the ratio with the other ingredients? Sorry, I'm just a bit new to this.

 

[lenarenee]

Thanks for the reply. I actually don't use any coconut oil( I'm allergic). I just use palm oil, palm kernel oil, a tiny bit of glycerin, lye and water. How would I go about lowering the superfat ( palm oil) without messing up the ratio with the other ingredients? Sorry, I'm just a bit new to this.

Sorry, that was supposed to be pko, not coconut. It was pko oil I entered into soap calculator.

Did you use a soap calculator for this recipe? There should be a box where it asks for a super fat percentage. Which calc are you using? And if this is a printed recipe from someone and you haven’t checked it with a calculator then we may have found the problem….aka their numbers are off and you have a higher super fat than they stated.

Oh, and do you know how pure your lye is? Is it food grade or hardware store grade? That can relate to super fat level or contaminant.

 

[Jen74]

Sorry, that was supposed to be pko, not coconut. It was pko oil I entered into soap calculator.

Did you use a soap calculator for this recipe? There should be a box where it asks for a super fat percentage. Which calc are you using? And if this is a printed recipe from someone and you haven’t checked it with a calculator then we may have found the problem….aka their numbers are off and you have a higher super fat than they stated.

Oh, and do you know how pure your lye is? Is it food grade or hardware store grade? That can relate to super fat level or contaminant.

I went through SoapCalc actually. The lye is get is food grade 100% sodium Hydroxide( Lye) and I order it online through Belle Chemical. I just wish I could figure this out. I just purchased a table top dehumidifier to see if placing that in the area will help. I am so at a loss and it is frustrating because this is the one soap I can use without having a reaction... So odd how it was fine all winter and now with the warmer weather it is giving me this issue. Our house is odd so not many rooms I can put it in to cure, so I use the kitchen/living room. I wonder if because we were painting the room a couple weeks ago and I had to move the soap for a few hours, could that have did it? I just cannot figure this out. I literally have a fan blowing on the soaps while they are curing constantly. This seemed to help all winter( at least I never had any soap go rancid). My one batch that went rancid I literally made like just 4 weeks ago almost so it was not even done curing( I cure mine for at least 6 weeks usually). I leave them out too so they have airflow even after they are cured. Not sure what to do.

 

[ResolvableOwl]

On top of this, a similar soap I made some time ago (but sans added glycerol) went rock hard within a mere day.

Just for fun (and to add some positive perspective), you could grate up a bit of your soap and stir it into the same weight of glycerol. Leave it a day or two, and then heat it up in the microwave or a water bath. It'll melt, turn transparent, and become glycerin soap (melt&pour base). That won't overcome rancidity, nor will it speed up drying/prevent sweating (rather the opposite). But at least the soap is doing something creative for you, not just constantly reminds you of weird/annoying things going on in your house.

 

[DeeAnna]

As far as metal contamination, please understand you aren't 100% in control of that. The harvesting and processing of fats requires machinery and equipment that is metal. Dust and air pollution and other random contamination can also add metal to the soap.

 

[Becky1024]

Can you post a picture of your rancid soap? It may help us figure out what is going on.

Also, how fast does your spring soap turn rancid?

I take it from your list of ingredients that you do not add any scent, colorant or other additives. Can you confirm that?

 

[earlene]

Hey everyone,

So I have been making my own soap now for about a year. I use just a few basic ingredients because my skin is Severely sensitive and I react to many things. I got it down to palm oil, palm kernel oil, lye, and water and I use the soap Calc. Those are my ingredients and they work well for me. Last year I noticed my soaps were getting rancid rather quickly and could not figure out why. I switched to making hot process soap and that seemed to help. I also started using a smal fan to blow on them while they are curing over the 4 to 6 weeks. Well everything was going great, no more rancid soap. Well now here in Chicago it is spring and the humidity is up. Well all my soap that I just made a couple months ago went rancid! The only thing that is different is that it seems like in the winter, the soap has no issues( it is also very dry in the house). What can I do to prevent this? I bought a small table top dehumidifier which I will get tomorrow. I am thinking maybe if I place this dehumidifier in the area where I cure the soaps this can help? We have the AC on as well on hot humid days. Should I also use a fan on the soaps along with the dehumidifier? I am at a loss and not sure what to do. I mean I lost like a whole batch of soap because it smells kind of rancid( that old oil smell). I do not think it is safe to use rancid soap right? Any suggestions? Does anyone else use a dehumidifier? Does this prevent soap going rancid?

Palm Oil and PKO should not start out rancid, so I would not suspect the oils, particularly if bought not too far in advance of making the soap. But I suppose in the right conditions, they could be rancid to start. I've just not had that happen.

Even though I would probably feel safe using both without an antioxidant, I'd still probably use ROE (Rosemary Oleoresin) and you can add Citric Acid for reduction of soap scum instead of EDTA. Or not. But the ROE does help prevent rancidity.

To address this question: I do not think it is safe to use rancid soap right? Yes, it is safe to use soap that has some rancidity. BUT you may not like to use it because of the smell. So if it's only a little rancid (a couple of spots here and there), you can cut them out and still use the soap. If it's widespread (throughout the entire bar), then the smell will be so strong you won't even want it in the house, that's when I would just toss it out and make new soap. But for a small DOS spot here and there, I'd cut them out, and do my best to keep the soap from developing more DOS.

Is there any sunshine in the room where you cure? Are your window curtains drawn at all times during the cure? Or does the sun shine into the room during the daylight hours? Sunshine is an enemy of curing soap.

I also live in hot & humid Illinois, so I get what you are experiencing, although I have not made soap with only that formula to compare to your exact experience. But hot humid conditions, yes. Even with the AC on in my house, the room where I cure gets hotter and curing soap only adds to the humidity in that room, because it IS releasing moisture into the air itself as it cures. So I keep a fan on at all times up there in the humid months.

Others do use portable dehumidifiers, but I have no desire to lug around a full bin of water to another room where I can empty it out every single day. We have one of those in my husband's basement office, and I hate emptying it even though there is a floor drain in the adjacent room. It gets heavy; it is cumbersome; it fills up in less than 24 hours, meaning it needs emptying every single day to be of any use to pull moisture from the air. I find a fan to be more convenient.

A couple of other suggestions:

Try a lower SF for your next soap. Maybe 2 or 3% SF and absolutely add ROE to the soap as an antioxidant. I would probably try at least one ZERO percent SF with a test batch as well. And then keep an eye on them; keep them away from any area that has sunshine coming in.

Test your lye purity. It is likely that your 100% pure lye has deteriorated in purity, by being exposed to the air (when opening the container), especially if the cap is left off for longer periods of time in the presence of high humidity. How to test for purity: NaOH or KOH purity check | Soapy Stuff

Alter your lye storage method to increase the life of the lye and decrease the likelihood of introducing moisture into the containers via ambient moisture in the air. This is how I store my lye as another member here at SMF once posted: My lye storage setup

ETA: I see you added glycerin to your formula. THAT is drawing moisture to the bar. I suggest leaving it out in the next couple of batches and seeing if that helps. It might be that your skin likes the extra glycerin in the winter, but perhaps you might need to adjust the formula for the Hot and Humid months to no-added glycerin. Soap has glycerin already without adding any extra.

 

[The_Phoenix]

I leave them out too so they have airflow even after they are cured.

When you say you "leave them out," what do you mean by that? Are they near any windows? In my opinion, the kitchen/living room is not an ideal spot to cure soap. The soap is exposed to every day air and activity. My hunch is that your curing location is most likely the culprit.

I cure my soaps in a closet under our staircase, resting on wooden shoe racks, lots of room to breathe, and they never see the light of day.

 

[earlene]

I went through SoapCalc actually. The lye is get is food grade 100% sodium Hydroxide( Lye) and I order it online through Belle Chemical. I just wish I could figure this out. I just purchased a table top dehumidifier to see if placing that in the area will help. I am so at a loss and it is frustrating because this is the one soap I can use without having a reaction... So odd how it was fine all winter and now with the warmer weather it is giving me this issue. Our house is odd so not many rooms I can put it in to cure, so I use the kitchen/living room. I wonder if because we were painting the room a couple weeks ago and I had to move the soap for a few hours, could that have did it? I just cannot figure this out. I literally have a fan blowing on the soaps while they are curing constantly. This seemed to help all winter( at least I never had any soap go rancid). My one batch that went rancid I literally made like just 4 weeks ago almost so it was not even done curing( I cure mine for at least 6 weeks usually). I leave them out too so they have airflow even after they are cured. Not sure what to do.

Re: could they have gone rancid because you moved them for a couple of hours, really depends more on the specific conditions than the amount of time.

When you do cure them do you use Metal racks or exposure to other possible contaminants? Even bare hands can transfer contaminants to soap during handling.

I would not cure in a kitchen, no matter how big my kitchen is because of heat fluctuations, oils from cooking, possible confusion of soap with food (my husband once said grated yellow soap looked like grated cheddar and that he was tempted to grab a taste.) Plus my kitchen has a window that I will never shade, and sunshine on curing soap is not beneficial to the soap.

And if your kitchen/living room is an open-floor plan type of setting, then I wouldn't want to cure the soap in that environment, either.

How one uses a living room is dependant on one's personal choices. Our living room and every living room in every house I have ever lived in has too many windows and too much activity for curing soap. I prefer to cure soap in an area without a lot of activity, in a dark space without access by visitors, pets (we only have a cat, but cat hairs on soap is not desirable), dust, etc.