Experiment on figuring out why my soaps keep going rancid

[Jen74]

Hey everyone.

So I know I've posted here a few times about my soap going rancid. Well I've been experimenting trying different things. My soap is pretty bland because I am allergic to So many things so the only oil I can tolerate is palm oil and palm kernel oil. My recipe is below.

Distilled water- 260.25 grams
Lye- 128.18 grams
Palm kernel oil - 181.44 grams
Palm oil- 725.75 grams

I thought maybe our home was too humid since my soaps always seem to go rancid in the summer months when the house is a bit more humid. I stated running a dehumidifier recently and that definitely took the humidity down in the house I made 2 batches of soap. One I used my original recipe above again and after 2 weeks into curing it was already smelling rancid as usual. The other batch I made did Not go rancid . That one I changed the calculations a little using soap calc adding a little more lye and a little more water. I guess by adding a little more lye and water it makes less super fat, at least that's what I read. I added 265.73 on the water and 130.88 on the lye. I kept everything else the same. I also added a little ROE to the soap when melting my oils ( I usually make HP soap). This batch of soap didn't go bad.

I notice my skin was a bit irritated using this soap( especially in private areas). I am not sure if it's from the ROE or changing the calculations a little. My question is, what do you think helped prevent this batch from going rancid, was it the Few drops of ROE I added or was it changing the calculations adding the little more lye and water? I need to make another batch and was thinking about either just making it using the recipe with the little
more lye and water, or going back to the original recipe and just add a few drops of ROE. Just trying to figure out what helped prevent the soaps from going rancid, the ROE or different calculation with adding more lye and water.. Your thoughts?

 

[kagey]

a few thoughts based on occam's razor:
we're told that rosemary EO helps prevent rancidity. so it seems that it's more likely the reason batch #2 is not rancid.

if you soaps go rancid more quickly in summer than winter -- that's another clue imho.
from a chem book:
"Fats and oils that are in contact with moist air at room temperature eventually undergo oxidation and hydrolysis reactions that cause them to turn rancid..."

which makes me wonder, if your soaps are stored in a way that they become rancid... how are you oils doing? heat and humidity with oxidation can cause them to age before their time. are they fresh? is your lye fresh? how long have you had any of this?

note: not only is humidity harmful to your soap and ingredients - but so is light and temperature. Are they all stored at 75 degress or less? are they exposed to sunlight?
"Rancidity is the process through which oils and fats become partially or completely oxidized after exposure to moisture, air, or even light. ... If the oil has no flavor, it is most likely rancid."

looking at your recipe -- you're soaping at 2:1 lye (33% lye concentration) -- which to me seem like an aweful lot of water for a very humid environment. I'm in a very humid climate - with dehumidifiers running constantly -- and I'm soaping at 35-40% lye concentration... and have had no problems with DOS or rancidity.

If you're making a basic soap with no swirls or "blue birds of happiness" () then, I don't see why you want trace to take so long. I'd recommend using less water. (Although I don't hot process my soaps, so maybe this isn't a real issue??)

Anyway -- I hope this provides some food for thought. I've been doing this for a whole lot less than nearly everybody here - and I'm able to avoid rancidity. And I use Palm Kernal Oil in my soaps. -- so if I can do it, you should be able to do it too.

 

[Jen74]

a few thoughts based on occam's razor:
we're told that rosemary EO helps prevent rancidity. so it seems that it's more likely the reason batch #2 is not rancid.

if you soaps go rancid more quickly in summer than winter -- that's another clue imho.
from a chem book:
"Fats and oils that are in contact with moist air at room temperature eventually undergo oxidation and hydrolysis reactions that cause them to turn rancid..."

which makes me wonder, if your soaps are stored in a way that they become rancid... how are you oils doing? heat and humidity with oxidation can cause them to age before their time. are they fresh? is your lye fresh? how long have you had any of this?

note: not only is humidity harmful to your soap and ingredients - but so is light and temperature. Are they all stored at 75 degress or less? are they exposed to sunlight?
"Rancidity is the process through which oils and fats become partially or completely oxidized after exposure to moisture, air, or even light. ... If the oil has no flavor, it is most likely rancid."

looking at your recipe -- you're soaping at 2:1 lye (33% lye concentration) -- which to me seem like an aweful lot of water for a very humid environment. I'm in a very humid climate - with dehumidifiers running constantly -- and I'm soaping at 35-40% lye concentration... and have had no problems with DOS or rancidity.

If you're making a basic soap with no swirls or "blue birds of happiness" () then, I don't see why you want trace to take so long. I'd recommend using less water. (Although I don't hot process my soaps, so maybe this isn't a real issue??)

Anyway -- I hope this provides some food for thought. I've been doing this for a whole lot less than nearly everybody here - and I'm able to avoid rancidity. And I use Palm Kernal Oil in my soaps. -- so if I can do it, you should be able to do it too.

Thank you for the input. I think it's impossible to keep air away from curing soaps since they are suppose to be in the air to cure? They are not in any direct sunlight. My dehumidifier kept the humidity between 36 and 42 percent at all times, sometimes lower. We have our AC running all the time, but the dehumidifier keeps it warmer in the house for some reason. I am just not sure how to proceed in terms of preventing my soaps from going rancid. It's like the whole bar Smells rancid yet without orange spots, but it definitely smells rancid. What do you mean about not wanting trace to take so long? ( lol, I'm also kind of new to this ).

 

[lenarenee]

Hmmm. Here’s a barrage of questions that come to mind: Are the oils freshly dated? Stored in as cool an environment as you can? Are you melting with low temps so the oils isn’t overheated? Using distilled water?

I would super fat at no more than 3%.

I believe Kevin Dunn said that roe with sodium citrate was best for preventing rancidity.

None of your soaps have orange discoloring? Since you’re sensitive to so many things, I wonder if what you think is rancidity, is actually just the smell of ….soap. Some of my plain unscented recipes have a very fatty smell….even those without animals fats. Palm and palm kernel are just not that prone to dos.

Palm shortening for food use has added bht and citric acid for freshness. what kind of palm are you using?

Are the oils the kind that have to be melted, mixed, then measured to ensure all the fatty acids are evenly dispersed? Shortening/ modern equivalent of hydrogenated don‘t require mixing.

The roe could be the source of the irritation you experienced because of the components in it. It also needs to be mixed into fresh oils thoroughly. Here is info from a very trusted source….
https://lotioncrafter.com/products/rosemary-oleoresin-roe
In the meantime, have you ever tried a detergent bar? I buy 100 Senses unscented bar for my colored hair and I immediately threw away all of my shampoo and conditioners! I’m incredibly impressed with their product!!!! My hair is better than when I used conditioner!

Be sure to read the ingredients, as it contains coconut fatty acid, and argan oil. The surfactants (detergents) are more modern ones and based from coconut or plants , rather than petroleum….in case that may affect your sensitivities.

 

[Jen74]

Hmmm. Here’s a barrage of questions that come to mind: Are the oils freshly dated? Stored in as cool an environment as you can? Are you melting with low temps so the oils isn’t overheated? Using distilled water?

I would super fat at no more than 3%.

I believe Kevin Dunn said that roe with sodium citrate was best for preventing rancidity.

None of your soaps have orange discoloring? Since you’re sensitive to so many things, I wonder if what you think is rancidity, is actually just the smell of ….soap. Some of my plain unscented recipes have a very fatty smell….even those without animals fats.

The roe could be the source of the irritation you experienced because of the components in it. It also needs to be mixed into fresh oils thoroughly. Here is info from a very trusted source….
https://lotioncrafter.com/products/rosemary-oleoresin-roe
In the meantime, have you ever tried a detergent bar? I buy 100 Senses unscented bar for my colored hair and I immediately threw away all of my shampoo and conditioners! I’m incredibly impressed with their product!!!! My hair is better than when I used conditioner!

Be sure to read the ingredients, as it contains coconut fatty acid, and argan oil. The surfactants (detergents) are more modern ones and based from coconut or plants , rather than petroleum….in case that may affect your sensitivities.
[/QUOTEt

Thanks for the response. The oils are all fresh that I use. I added the ROE to my batch of soap when I'm making the batch( while I'm melting my oils). I cannot add it to the oil container as the oil is solidified. I add when I'm melting it down. I have Very sensitive skin and have tried many many soaps to no avail. Most have lots of different ingredients and oils. I am allergic to coconut so that makes it hard too as lots of commercial soaps have coconut oil added. I think my recipe is only 3 Percent super fat. I will have to check. It's very frustrating to say the least. Isn't sodium citrate salt? Wouldn't that also be irritating to the skin? How much Sodium citrate is supposed to be added and when do you add it? Sorry for all the questions, I'm new to this..

 

[lenarenee]

@Jen74 Ask all the questions you need to….you have a need for special soap, not a hobby.

Sodium citrate is a type of salt, but so is soap. Soap is the salt of fatty acids. You maybe thinking of sodium chloride, which can be irritating if exposed to skin for a long time. But people use salt now for scrubs, as swimming pool additives, etc.

Are the oils you have hydrogenated?

 

[kagey]

I think it's impossible to keep air away from curing soaps since they are suppose to be in the air to cure?

I'm not suggesting keeping air away from your curing soaps -- just bad air. For example don't cure in garage where you store your car. Or humidity.

We have our AC running all the time, but the dehumidifier keeps it warmer in the house for some reason

your dehumidifier creates heat - that's how it separates the moisture from the air.

What do you mean about not wanting trace to take so long?

I use Cold Process -- and most who do this try to keep their soaps from tracing fast in order to incorporate designs. More water typically equals slower saponification.
Since you're doing Hot Process -- I guess it doesn't matter as much -- unless your interior air quality is poor. I would use less water than your current recipe.

Without knowing more about your process -- it's hard to analyze what might be going wrong.
on the surface, your recipe seems fine.
it doesn't have too much unsaturated fats (which is typically what cause rancidity).

where do you store your soaps?
if you're using your soaps within the first 2 weeks and they irriate -- it may be that the lye was not all neutralized. Have you tried the zap test?
which brings me back to your oils -- if you're doing everything right, then your ingredients may be bad.

it's not normal for your soaps to smell rancid after just 2 weeks.

 

[amd]

Reverse calculating your recipe, it looks like you changed from 5% SF to 3% SF, so your lye amounts and water amounts adjusted accordingly. Correct?

Perhaps it was asked in the other threads regarding your issue, but please share again, what are you using for water? Is it tap or purchased distilled?
If you are using tap, it may be a matter of the way that the water is treated in the summer vs other months of the year. I did an internship at our water treatment facility during college, and learned the treatments for tap water can vary during the year. (That was about the only thing I retained from that internship and did not go to work in that field, so bear with my 22 year old memories)

 

[Jen74]

@Jen74 Ask all the questions you need to….you have a need for special soap, not a hobby.

Sodium citrate is a type of salt, but so is soap. Soap is the salt of fatty acids. You maybe thinking of sodium chloride, which can be irritating if exposed to skin for a long time. But people use salt now for scrubs, as swimming pool additives, etc.

Are the oils you have hydrogenated?

No the oils are not hydrogenated. Is it better to use hydrogenated oils?

 

[Jen74]

Reverse calculating your recipe, it looks like you changed from 5% SF to 3% SF, so your lye amounts and water amounts adjusted accordingly. Correct?

Perhaps it was asked in the other threads regarding your issue, but please share again, what are you using for water? Is it tap or purchased distilled?
If you are using tap, it may be a matter of the way that the water is treated in the summer vs other months of the year. I did an internship at our water treatment facility during college, and learned the treatments for tap water can vary during the year. (That was about the only thing I retained from that internship and did not go to work in that field, so bear with my 22 year old memories)

I use distilled water.

 

[Jen74]

I'm not suggesting keeping air away from your curing soaps -- just bad air. For example don't cure in garage where you store your car. Or humidity.


your dehumidifier creates heat - that's how it separates the moisture from the air.


I use Cold Process -- and most who do this try to keep their soaps from tracing fast in order to incorporate designs. More water typically equals slower saponification.
Since you're doing Hot Process -- I guess it doesn't matter as much -- unless your interior air quality is poor. I would use less water than your current recipe.

Without knowing more about your process -- it's hard to analyze what might be going wrong.
on the surface, your recipe seems fine.
it doesn't have too much unsaturated fats (which is typically what cause rancidity).

where do you store your soaps?
if you're using your soaps within the first 2 weeks and they irriate -- it may be that the lye was not all neutralized. Have you tried the zap test?
which brings me back to your oils -- if you're doing everything right, then your ingredients may be bad.

it's not normal for your soaps to smell rancid after just 2 weeks.

I story soaps on a shelf ( plastic) in the living room area. Our house is small ( we have open concept kitchen living room). I know it's not ideal, but it is the least humid place in the house. Our bedroom has the bathroom where we shower so it gets more humid in our bedroom. I Figured the basement was a no since basements are naturally more humid. I usually cure my soap for 4 weeks before using it.

 

[lenarenee]

No the oils are not hydrogenated. Is it better to use hydrogenated oils?

This may be the issue. Who is the oil supplier? Any label saying “no stir”?

With unhydrogenated palms, the entire container has to be melted, mixed thoroughly, then batch oils measured out. Every time. The fatty acids separate, and that can throw off the saponification of the oil used….meaning your soap MAY be more super fatted than you want. (Or lye heavy, depending on where the fatty acids collected when they solidified)


That’s about the extent of my knowledge on the matter. I’d like to get someone like @deanna @dibbles or others to voice their opinions on the palm.

 

[Jen74]

This may be the issue. Who is the oil supplier? Any label saying “no stir”?

With unhydrogenated palms, the entire container has to be melted, mixed thoroughly, then batch oils measured out. Every time. The fatty acids separate, and that can throw off the saponification of the oil used….meaning your soap MAY be more super fatted than you want. (Or lye heavy, depending on where the fatty acids collected when they solidified)


That’s about the extent of my knowledge on the matter. I’d like to get someone like @deanna @dibbles or others to voice their opinions on the palm.

I get my oils from a place called soapers choice.

 

[Jen74]

This may be the issue. Who is the oil supplier? Any label saying “no stir”?

With unhydrogenated palms, the entire container has to be melted, mixed thoroughly, then batch oils measured out. Every time. The fatty acids separate, and that can throw off the saponification of the oil used….meaning your soap MAY be more super fatted than you want. (Or lye heavy, depending on where the fatty acids collected when they solidified)


That’s about the extent of my knowledge on the matter. I’d like to get someone like @deanna @dibbles or others to voice their opinions on the palm.

These are the soaps.

 

[lenarenee]

Ok, so one is hydrogenated and one isn’t. I’m going to do a little research and get back to you.

ETA: Okay, that was easy. It’s probably not an issue. Some highly experienced soapers on this forum have stated they don’t melt and stir their unhydrogenated palms. It seems that only harmless stearic spots are the most common issue.

So, I’d have to say that your successful soap was due to a combination of the lower humidity, roe, and lower super fat.

The change in amount of lye and water is not a factor, because that’s due to the changes in your recipe. With a well formulated recipe and accurate measurement, there’s no lye left in your soap 24 to 48 hours after you make it.

I couldn’t find information stating roe was a skin irritant. Lotioncrafter made a point of stating theirs is low in carnosic acid….and that makes me think high carnosic levels are not wanted. So…this may be an issue for you.

Other things to try:

Let your good soap cure for a few more weeks then use it again….carefully…to see if it still irritates. The pH of soap slowly lowers a bit as it cures, and can become gentler.

I would try a small batch with bht instead of roe.

Continue with a low super fat.

Continue dehumidifying. Since you don’t have this problem in the winter, humidity is likely a big factor.

Wrap the soap in plastic when it’s 6 to 8 weeks cured. Dust (metal particles in the air) can cause dos, plastic helps control the moisture. Also, muslin fabric is recommended by some shapers too to help soap stay fresh longer.

Here’s what our member Deanna has to say about rancidity: Rancidity and DOS | Soapy Stuff

Any other questions?

 

[Jen74]

Ok, so one is hydrogenated and one isn’t. I’m going to do a little research and get back to you.

ETA: Okay, that was easy. It’s probably not an issue. Some highly experienced soapers on this forum have stated they don’t melt and stir their unhydrogenated palms. It seems that only harmless stearic spots are the most common issue.

So, I’d have to say that your successful soap was due to a combination of the lower humidity, roe, and lower super fat.

The change in amount of lye and water is not a factor, because that’s due to the changes in your recipe. With a well formulated recipe and accurate measurement, there’s no lye left in your soap 24 to 48 hours after you make it.

I couldn’t find information stating roe was a skin irritant. Lotioncrafter made a point of stating theirs is low in carnosic acid….and that makes me think high carnosic levels are not wanted. So…this may be an issue for you.

Other things to try:

Let your good soap cure for a few more weeks then use it again….carefully…to see if it still irritates. The pH of soap slowly lowers a bit as it cures, and can become gentler.

I would try a small batch with bht instead of roe.

Continue with a low super fat.

Continue dehumidifying. Since you don’t have this problem in the winter, humidity is likely a big factor.

Wrap the soap in plastic when it’s 6 to 8 weeks cured. Dust (metal particles in the air) can cause dos, plastic helps control the moisture. Also, muslin fabric is recommended by some shapers too to help soap stay fresh longer.

Any other question?

Try sodium citrate, a chelator.

Thank you for the response and all the help. I agree with all you have said. I will try making the batch again with the ROE and more lye like before. I bought a jeweler's scale to measure out the ROE. How much should I put for 2 lbs of soap? I just added like a few drops this last time. What is BHT? Would this be used in place of ROE? Does it help prevent rancidity? Thanks so much for all your help..

 

[paradisi]

Occasionally Soapers Choice has shipped oils that accidentally had other oils in them, corn oil in palm or coconut for one, and mixed shortening for palm, in another. Have you tried oils from a different supplier?

 

[lenarenee]

[QUOTE="Jen74, post: 907407, member: 34
Thank you for the response and all the help. I agree with all you have said. I will try making the batch again with the ROE and more lye like before. I bought a jeweler's scale to measure out the ROE. How much should I put for 2 lbs of soap? I just added like a few drops this last time. What is BHT? Would this be used in place of ROE? Does it help prevent rancidity? Thanks so much for all your help..♥
[/QUOTE]

One reason I started making soap myself is because when I moved to dry S. California - there was no soap sold in stores that didn't suck the life out of my skin. So I completely understand your mission!!

Wait a sec...why the batch with more lye? That is the lower super fat one?

The jeweler's scale for the roe is a wonderful choice - you can then measure the least amount recommended in case that is what is irritating your skin.

Although, now that I think more about it, since you have fresh oils from a reputable supplier, and palm and palm kernel are just not that prone to dos, you could make a 1 pound batch of soap without the roe - BUT continue with the dehumidifying and a low super fat.

If I remember correctly, ROE comes in different strengths. Your supplier may have given you a recommended amount...? I'm going to take this directly from Deanna's website: (italicized). ***keep in mind that more is NOT better; too much ROE causes rancidity!!*
suggest no more than 0.5 grams ROE per 1000 grams of fat (0.05% based on total fat weight) to help preserve fats in storage or for use in soap.

ROE weight = Fat weight X 0.05 / 100 = Fat weight X 0.0005

The dosage range I have found reported in the literature is 0.2 to 1.0 g ROE per 1000 g fat (0.02% to 0.1% based on total fat weight). If you want to use another dosage other than 0.05%, replace the 0.05 in the formula above with the number you want to use instead.

These numbers are based on ROE with 5% to 7% carnosic acid content. If the carnosic acid content in your ROE is lower than that, then adjust the dosage accordingly.

Kevin Dunn recommends 1.0 g ROE for every 1000 g oils (0.1% of total fat weight) to be added when making soap. He found ROE by itself to be an effective "natural" treatment for rancidity (DOS, dreaded orange spots) in soap. He suggests an even more effective but less "natural" combination of 1.0 g ROE and 0.5 g tetrasodium EDTA powder for every 1000 g oils. (3)

Yes, bht does what roe does. Its very common in fats used for food service to prevent rancidity. I have bought 50lb cubes of palm, lard, and tallow all with but and citric acid added. They're stored in a dark cool closet in the garage, not the ideal conditions - but they last for years. The palm is 3 years old, and what I don't finish this year will just be tossed.

Did I cover everything?

 

[Mobjack Bay]

Occasionally Soapers Choice has shipped oils that accidentally had other oils in them, corn oil in palm or coconut for one, and mixed shortening for palm, in another. Have you tried oils from a different supplier?

Can you explain this more fully? Did this happen to you? The products I’ve ordered over the last year or more looked right, had the right texture, soaped properly etc. I use their no-stir palm, tallow, shea, HO sunflower and most recently ordered RBO that I haven’t soaped with yet.

 

[paradisi]

To me this year (shortening or some other high melt palm blend that stayed solid at well over 100 degrees for days, in the sun on my porch, instead of rspo palm which if course ought to have been liquid the first afternoon for stirring); to another member here a couple years ago (the corn oil adulteration), and to a soaper on another forum I know (cocoa butter with something chalky in it), etc.

I got organic palm from them for many years, but have switched to a different supplier as they refused to admit there was anything wrong, even with photos.

So, yeah, the problem isn't always the soaper, sometimes it's the materials.

Can you explain this more fully? Did this happen to you? The products I’ve ordered over the last year or more looked right, had the right texture, soaped properly etc. I use their no-stir palm, tallow, shea, HO sunflower and most recently ordered RBO that I haven’t soaped with yet.