Soap Gone Bad

[Steve_in_CT]

I have had many soaps, and I have had many of them for more than a year or two, but this is the first time I've had one go bad. To be fair, I'm not sure that the soap was all that fresh when I got it, but even so it surprises me. It was a tub of Flying Mango, which is made by Saponificio Varesino for Bullgoose Shaving. My initial reaction when I received the soap a year of so ago was that the fragrance seemed a bit off, but by the time I pulled it to use it again yesterday, it had clearly turned. One or more of the oils had clearly gone rancid. It had the same smell as a stale jar of nuts, or an old bottle of olive oil.

I'm not particularly bothered by it, as I didn't enjoy that soap all that much, but I'm curious as to why it's the first and only soap to which that has happened. They are all stored in the same place, so it must be something in the soap's composition. Too many oils? A particular oil that is more subject to spoiling? Have you had this happen with any of your soaps? If so, which ones? It would be good to know if there is a particular ingredient(s) that makes some soaps more subject to spoilage over time.

 

[DEgeezer]

I keep my Cella red in the fridge because others have said that it can go bad in hot weather.
I had a tub of TSE go bad in 3 or 4 months. It contains a lot of tallow, so maybe that's the reason.

 

[luvmysuper]

Is it a hard soap or a "soft" soap?
I can possibly see it with a soft soap, but a cured hard soap, even tallow - isn't likely to go bad, unless it's being soaked in water for an extended period of time.
I have dozens and dozens of hard soaps, some more than 50 or 60 years old and I have never had an issue.

 

[Steve_in_CT]

Is it a hard soap or a "soft" soap?
I can possibly see it with a soft soap, but a cured hard soap, even tallow - isn't likely to go bad, unless it's being soaked in water for an extended period of time.
I have dozens and dozens of hard soaps, some more than 50 or 60 years old and I have never had an issue.

I would consider it a moderately hard soap. While I don't have any soaps that are 50 years old, I have a couple that are at least 10 years old, and they are just fine. I don't remember my chemistry too well, but I think the issue comes down to some of the oils that are added into the soap. I'm not sure what is supposed to stabilize them to keep them from going rancid, since oil will go rancid over time.

 

[RayClem]

I do not know which SV soap formula you have. I had a Beta 4.3 soap that had the following ingredients:

Sodium Cocoate, Potassium Stearate, Sodium Cocoyl Isethionate, Sodium Rapeseedate, Sodium Sunflowerseedate, Aqua/Water/Eau, Fraxinus Ornus (Manna Ash) Sap Extract, Coco Glucoside, Glyceryl Oleate, Erythritol, Ricinus Communis Oil, Hydrogenated Castor Oil, Copernica Cerifera Cera, Cera Alba, Galactoarabinan, Shorea Stenoptera Seed Butter, Parfum/Fragrance, Macadamia Ternifolia Seed Oil, Sucrose Cocoate, Butyrospermum Parkii (Shea) Butter, Prunus Amygdalus Dulcis (Sweet Almond) Oil, Oryza Sativa (Rice) Starch, Xanthan Gum, Glycerin, Stearic Acid, Sodium Chloride, Tocopheryl Acetate, Vitis Vinifera (Grape) Seed Oil, Citric Acid, Limonene, Coumarin, Benzyl Benzoate, Linalool, Citronellol, Geraniol.

Rapeseed is the seed from which we get canola oil. Sunflower seed is the seed from which we get sunflower oil. Both of these oils are low in saturated fatty acids, high in monosaturated fatty acids and unsaturated fatty acids. While soaps made from saturated and monosaturated fatty acids can have a very long shelf life, unsaturated fatty acids like those in canola oil and sunflower oil oxidize quite readily. These oils are great for cooking as they are high in Omega 6 and Omega 3 fatty acids, but it reduces the shelf life. While a bottle of these oils will last a couple of years in a dark pantry when opened, once the cap is removed and the oils are exposed to oxygen, it is recommended to use these oils within a year to avoid them becoming rancid. It is likely these two oils that are causing your soap to go bad once exposed to oxygen.

 

[Steve_in_CT]

I do not know which SV soap formula you have. I had a Beta 4.3 soap that had the following ingredients:

Sodium Cocoate, Potassium Stearate, Sodium Cocoyl Isethionate, Sodium Rapeseedate, Sodium Sunflowerseedate, Aqua/Water/Eau, Fraxinus Ornus (Manna Ash) Sap Extract, Coco Glucoside, Glyceryl Oleate, Erythritol, Ricinus Communis Oil, Hydrogenated Castor Oil, Copernica Cerifera Cera, Cera Alba, Galactoarabinan, Shorea Stenoptera Seed Butter, Parfum/Fragrance, Macadamia Ternifolia Seed Oil, Sucrose Cocoate, Butyrospermum Parkii (Shea) Butter, Prunus Amygdalus Dulcis (Sweet Almond) Oil, Oryza Sativa (Rice) Starch, Xanthan Gum, Glycerin, Stearic Acid, Sodium Chloride, Tocopheryl Acetate, Vitis Vinifera (Grape) Seed Oil, Citric Acid, Limonene, Coumarin, Benzyl Benzoate, Linalool, Citronellol, Geraniol.

Rapeseed is the seed from which we get canola oil. Sunflower seed is the seed from which we get sunflower oil. Both of these oils are low in saturated fatty acids, high in monosaturated fatty acids and unsaturated fatty acids. While soaps made from saturated and monosaturated fatty acids can have a very long shelf life, unsaturated fatty acids like those in canola oil and sunflower oil oxidize quite readily. These oils are great for cooking as they are high in Omega 6 and Omega 3 fatty acids, but it reduces the shelf life. While a bottle of these oils will last a couple of years in a dark pantry when opened, once the cap is removed and the oils are exposed to oxygen, it is recommended to use these oils within a year to avoid them becoming rancid. It is likely these two oils that are causing your soap to go bad once exposed to oxygen.

Thanks, @RayClem. The tin, which I no longer have, did reference the Beta 4.3 formula, so I suspect it is the same or very similar to the list of ingredients that you posted. Now that I know which oils oxidize quickly, I'll make sure that I don't store soaps containing those oils for extended periods of time.

 

[luvmysuper]

I can assure you that the 50 or 60 year old soaps I have don't have sunflower, canola, or any other vegetable based oil in the recipe!
One would think that proper saponification would render these oils stable, but I guess not?

 

[macintoshBR]

I do not know which SV soap formula you have. I had a Beta 4.3 soap that had the following ingredients:

Sodium Cocoate, Potassium Stearate, Sodium Cocoyl Isethionate, Sodium Rapeseedate, Sodium Sunflowerseedate, Aqua/Water/Eau, Fraxinus Ornus (Manna Ash) Sap Extract, Coco Glucoside, Glyceryl Oleate, Erythritol, Ricinus Communis Oil, Hydrogenated Castor Oil, Copernica Cerifera Cera, Cera Alba, Galactoarabinan, Shorea Stenoptera Seed Butter, Parfum/Fragrance, Macadamia Ternifolia Seed Oil, Sucrose Cocoate, Butyrospermum Parkii (Shea) Butter, Prunus Amygdalus Dulcis (Sweet Almond) Oil, Oryza Sativa (Rice) Starch, Xanthan Gum, Glycerin, Stearic Acid, Sodium Chloride, Tocopheryl Acetate, Vitis Vinifera (Grape) Seed Oil, Citric Acid, Limonene, Coumarin, Benzyl Benzoate, Linalool, Citronellol, Geraniol.

Rapeseed is the seed from which we get canola oil. Sunflower seed is the seed from which we get sunflower oil. Both of these oils are low in saturated fatty acids, high in monosaturated fatty acids and unsaturated fatty acids. While soaps made from saturated and monosaturated fatty acids can have a very long shelf life, unsaturated fatty acids like those in canola oil and sunflower oil oxidize quite readily. These oils are great for cooking as they are high in Omega 6 and Omega 3 fatty acids, but it reduces the shelf life. While a bottle of these oils will last a couple of years in a dark pantry when opened, once the cap is removed and the oils are exposed to oxygen, it is recommended to use these oils within a year to avoid them becoming rancid. It is likely these two oils that are causing your soap to go bad once exposed to oxygen.

I’m not one to doubt your answer, but both rapeseed and sunflower oils used are the respective saponified sodium salts. There should be no extra oils left otherwise they’d have to indicate in the INCI. It could be something else. There are several butters and unsaponified oils listed in the ingredients

 

[samballat]

I had a soap gone bad (mold) but I blame myself for that cause it happened within a month of purchase. I used dirty water from the sink (so relatively clean, but not clean enough) with soap residue and cutoff wiskers, on my brush to get more product and then I did not let it dry enough and there were mold spots on the side of the can and the bottom where the water had leaked through. Lesson learned.I scooped out about 90% of the remaining soap, after all that was still fine and cleaned the container.

 

[sarimento1]

I have had many soaps, and I have had many of them for more than a year or two, but this is the first time I've had one go bad. To be fair, I'm not sure that the soap was all that fresh when I got it, but even so it surprises me. It was a tub of Flying Mango, which is made by Saponificio Varesino for Bullgoose Shaving. My initial reaction when I received the soap a year of so ago was that the fragrance seemed a bit off, but by the time I pulled it to use it again yesterday, it had clearly turned. One or more of the oils had clearly gone rancid. It had the same smell as a stale jar of nuts, or an old bottle of olive oil.

I'm not particularly bothered by it, as I didn't enjoy that soap all that much, but I'm curious as to why it's the first and only soap to which that has happened. They are all stored in the same place, so it must be something in the soap's composition. Too many oils? A particular oil that is more subject to spoiling? Have you had this happen with any of your soaps? If so, which ones? It would be good to know if there is a particular ingredient(s) that makes some soaps more subject to spoilage over time.

with perhaps hundreds of soaps over the years, never had one to go bad.
you had an unfortunate experience, perhaps due to an untested batch from the artisanal maker and/or poor storage conditions.
toss it and shrug it off!

 

[nemo]

... It could be something else. There are several butters and unsaponified oils listed in the ingredients

Yep, probably one of those added oils turned, like castor or macadamia oil.
I've had one hard soap go bad and it smelled rotten. Toss it.

 

[Steve56]

I’ve had my Flying Mango 4.3 for a couple of years maybe, the second release, and it’s fine. It’s a hard, teiple milled soap and this is the first time that I’ve heard of one going bad. Got an image?

 

[NorthernSoul]

I can assure you that the 50 or 60 year old soaps I have don't have sunflower, canola, or any other vegetable based oil in the recipe!
One would think that proper saponification would render these oils stable, but I guess not?

Yes, but some modern soaps are super-fatted, meaning extra fats are added that don't get saponified. These fats are supposed to replace part of the skin oils that are stripped off by the soap. One of these fats might be causing the problem.

 

[RayClem]

I’m not one to doubt your answer, but both rapeseed and sunflower oils used are the respective saponified sodium salts. There should be no extra oils left otherwise they’d have to indicate in the INCI. It could be something else. There are several butters and unsaponified oils listed in the ingredients

Saponification is the process by which a fatty acid is reacted with an alkali such as sodium or potassium hydroxide The result is a sodium or potassium salt called an ester. The reaction occurs between the hydrogen end of the fatty acid and the sodium or potassium ion of the alkali. This reaction does nothing to change the structure of the carbohydrate chain in the original fatty acid. Thus, a saturated fatty acid like stearic and palmitic acids become saturated fatty esters; monounsaturated fatty acids like oleic retain their monounsaturated structure, and polyunsaturated fatty acids retain their polyunsaturated structure.

Thus, soaps made using polyunsaturated fatty acids will deteriorate more quickly than soaps without them. Traditional vintage soaps were primarily produced from tallow or lard which are comprised largely of saturated fatty acids and monosaturated fatty acids that are far less likely to go rancid. However, monosaturated fats like oleic acid will eventually turn rancid.

Just because a soap does not contain animal fats does not mean that is it lacks saturated fatty acids. Palm oil, palm kernel oil, coconut oil, Shea butter and some other vegetable and nut oils are high in saturated fatty acids. Shea butter has more stearic acid than beef tallow. It is only when vegetable oils high in polyunsaturated Omega 3 and Omega 6 fats are included does the soap become more easily oxidized. That will happen with or without saponification.

 

[CCS]

Is it a hard soap or a "soft" soap?
I can possibly see it with a soft soap, but a cured hard soap, even tallow - isn't likely to go bad, unless it's being soaked in water for an extended period of time.
I have dozens and dozens of hard soaps, some more than 50 or 60 years old and I have never had an issue.

The only thing I've ever had turn was a tub of Cella. Quite a rancid smell. However, I've got a few pucks of vintage Old Spice soaps that smell fine, if not fairly weak. Same with some Colgate, and old Williams.

 

[Mike M]

Had a tub of Cella that started turning, the scent changed a bit and it started to get a textured look to it with something like little balls on it. It didn't effect the performance though so I 3017d it, good soap but I don't think I will be buying another any time soon.

 

[RayClem]

The only thing I've ever had turn was a tub of Cella. Quite a rancid smell. However, I've got a few pucks of vintage Old Spice soaps that smell fine, if not fairly weak. Same with some Colgate, and old Williams.

Old Spice, Colgate and Williams were all hard pucks made from simple tallow-based formulas. They can last for decades because they do not contain fats that easily go rancid.

 

[luvmysuper]

Credit to Gary Larson

 

[thombrogan]

My sample-sized Stirling Sheep got moldy after a few months waiting for me to lay off the ARKO! and Col Conk. The three-four times I used it before then were exceptional.

 

[kingfisher]

Saponification is the process by which a fatty acid is reacted with an alkali such as sodium or potassium hydroxide The result is a sodium or potassium salt called an ester. The reaction occurs between the hydrogen end of the fatty acid and the sodium or potassium ion of the alkali. This reaction does nothing to change the structure of the carbohydrate chain in the original fatty acid. Thus, a saturated fatty acid like stearic and palmitic acids become saturated fatty esters; monounsaturated fatty acids like oleic retain their monounsaturated structure, and polyunsaturated fatty acids retain their polyunsaturated structure.

Thus, soaps made using polyunsaturated fatty acids will deteriorate more quickly than soaps without them. Traditional vintage soaps were primarily produced from tallow or lard which are comprised largely of saturated fatty acids and monosaturated fatty acids that are far less likely to go rancid. However, monosaturated fats like oleic acid will eventually turn rancid.

Just because a soap does not contain animal fats does not mean that is it lacks saturated fatty acids. Palm oil, palm kernel oil, coconut oil, Shea butter and some other vegetable and nut oils are high in saturated fatty acids. Shea butter has more stearic acid than beef tallow. It is only when vegetable oils high in polyunsaturated Omega 3 and Omega 6 fats are included does the soap become more easily oxidized. That will happen with or without saponification.

This may be true, but I highly suspect that a lot of the modern artisan soaps also use a "lye discount" to purposefully leave a percentage of the added oils unsaponifed, for "face feel" purposes.

I am not a chemist, but my educated guess would be that unsaponified or "superfatted" fatty acids would almost certainly go rancid well before their fully saponified versions did.