Will sodium Citrate prevent soap going rancid?

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DeeAnna

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I've told this story elsewhere, but I'll recap it here --

I gave a friend a few unwrapped bars of my soap at a time in my soapy adventures before I started using ROE and EDTA. I kept one unused bar in a box as a long-term sample and used the rest.

Some time after that -- maybe 6 months or a year later -- she and I were talking about my soap and she pulled out the bars I'd given her. She apparently didn't see anything wrong with them, but I was mortified -- her bars had turned nasty rancid.

I grabbed the bars and took them home without asking her if I could -- I was so embarrassed I forgot to be polite -- and raced to my sample box and found the bar I'd kept. It was fine -- no DOS, no overall rancidity, no "off" smell. Nothing.

I have no idea what she did differently, but obviously she had stored her soap differently than I do. As the Soapsmith experiment shows, the environment in which soap is stored can have a huge effect on the useful shelf life of soap.

The lesson I learned -- while I might be able to minimize rancidity and DOS when soap is in my keeping, I can't police how my friends and customers treat my soap. I need to ensure my soap stays nice regardless of whether they store the soap in a cool, dark, dry place (as I do) or store it on a sunny windowsill. Or whatever. That's why I started using a chelator and an antioxidant to extend the shelf life of my soap and soap making fats.

I sell soap and other items at a local gift shop and occasionally visit the shop to deliver new product and check on the appearance of the stock they have on hand. I pulled several bars of soap last fall that had been on display in a sunny, hot window along the west sidewalk. The colors of the soap and on the labels had faded so the bars looked shopworn, but there was no evidence of rancidity either by smell or to the eye. I was pretty happy to see the soap did okay despite this treatment.
 

Jen74

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I've told this story elsewhere, but I'll recap it here --

I gave a friend a few unwrapped bars of my soap at a time in my soapy adventures before I started using ROE and EDTA. I kept one unused bar in a box as a long-term sample and used the rest.

Some time after that -- maybe 6 months or a year later -- she and I were talking about my soap and she pulled out the bars I'd given her. She apparently didn't see anything wrong with them, but I was mortified -- her bars had turned nasty rancid.

I grabbed the bars and took them home without asking her if I could -- I was so embarrassed I forgot to be polite -- and raced to my sample box and found the bar I'd kept. It was fine -- no DOS, no overall rancidity, no "off" smell. Nothing.

I have no idea what she did differently, but obviously she had stored her soap differently than I do. As the Soapsmith experiment shows, the environment in which soap is stored can have a huge effect on the useful shelf life of soap.

The lesson I learned -- while I might be able to minimize rancidity and DOS when soap is in my keeping, I can't police how my friends and customers treat my soap. I need to ensure my soap stays nice regardless of whether they store the soap in a cool, dark, dry place (as I do) or store it on a sunny windowsill. Or whatever. That's why I started using a chelator and an antioxidant to extend the shelf life of my soap and soap making fats.

I sell soap and other items at a local gift shop and occasionally visit the shop to deliver new product and check on the appearance of the stock they have on hand. I pulled several bars of soap last fall that had been on display in a sunny, hot window along the west sidewalk. The colors of the soap and on the labels had faded so the bars looked shopworn, but there was no evidence of rancidity either by smell or to the eye. I was pretty happy to see the soap did okay despite this treatment.



Thank you for sharing your story. Very interesting. So basically when you started adding the ROE and EDTA to your soap batches, they did not go rancid as much? Mine are not even being stored, they go rancid two to three weeks into curing. It's carzy because I can smell it before there are any DOS spots on them even. It is a very nasty distinct smell too. I can really smell it because I do not even add any fragrances to my soap due to my allergies. I ordered some ROE to use in my next batch. I was wondering, where do you buy EDTA? Would using only ROE be enough to help prevent rancidity? I think humidity is playing a huge part in my issue with the soaps going rancid. During the winter I do not have this issue and the only difference is the house is very dry...
 

DeeAnna

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Thank you for sharing your story. Very interesting. So basically when you started adding the ROE and EDTA to your soap batches, they did not go rancid as much?...

That experience with my friend's rancid soap was really embarrassing. But I got over it and changed how I do things for the better.

Using EDTA and ROE have reduced the chance of rancidity in my soap by a lot -- to the point that I don't really think about the problem anymore, except when other people want to talk about it. I'm not seeing any orange-y blotches or spots and I'm not smelling any off smells. That's not to say rancidity will never happen, just that it's a lot less likely.

If I had to use just one -- a chelator or an antioxidant -- I would choose the chelator. But I strongly recommend both. ROE is especially helpful if your recipes are higher in polyunsaturated fats or if you render your own lard or tallow.

FWIW, I'm not stuck on using EDTA -- I want to switch to sodium gluconate when my EDTA stash gets used up.
 

Jen74

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That experience with my friend's rancid soap was really embarrassing. But I got over it and changed how I do things for the better.

Using EDTA and ROE have reduced the chance of rancidity in my soap by a lot -- to the point that I don't really think about the problem anymore, except when other people want to talk about it. I'm not seeing any orange-y blotches or spots and I'm not smelling any off smells. That's not to say rancidity will never happen, just that it's a lot less likely.

If I had to use just one -- a chelator or an antioxidant -- I would choose the chelator. But I strongly recommend both. ROE is especially helpful if your recipes are higher in polyunsaturated fats or if you render your own lard or tallow.

FWIW, I'm not stuck on using EDTA -- I want to switch to sodium gluconate when my EDTA stash gets used up.


Thanks for the suggestions. I honestly think you are right, I need to add a chelator and the ROE. I think it might at least help prevent the rancidity. For me humidity definitely is playing a role because in the winter I can make soap with No preservatives and it never goes randcid. I had this same problem last summer too. It is frustrating because I have Mast cell activation syndrome and have to be careful as I react to lots of things which is why I kind of avoided adding too many preservatives. I guess I am going to have to just to see if it will stop my soaps from going rancid.
 

AAShillito

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Thanks for the suggestions. I honestly think you are right, I need to add a chelator and the ROE. I think it might at least help prevent the rancidity. For me humidity definitely is playing a role because in the winter I can make soap with No preservatives and it never goes randcid. I had this same problem last summer too. It is frustrating because I have Mast cell activation syndrome and have to be careful as I react to lots of things which is why I kind of avoided adding too many preservatives. I guess I am going to have to just to see if it will stop my soaps from going rancid.
How long does it take to use one bar? Maybe don't make too much ahead. Like only 1 four bar batch and start the next batch 1/2 through ?
 

earlene

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@AAShillito's suggestion is a good one.

If humidity is part of the problem, do your soaps also sweat in the summer? If that is the case, I would also suggest this: At least a month or so before your humid weather is due, wrap & label your soap, then store in a cardboard box along with a desiccant like DampRid to absorb any moisture that may arise (like when you open the box to pull out a new bar of soap to replace one you have used up.)

In spite of having Central Air Conditioning with De-humidification, I still can get soaps sweating in the summertime in certain rooms. So I use a medium to largish sized desiccant water-collection tub (DampRid or other brands) in the room where I cure my soaps. I also use a powerful fan to blow move the air in the room, which also helps. Not just a ceiling fan, but a powerful fan that really moves the air a lot.

When I use only a ceiling fan, the soap can still sweat. I found what works for me, but what works for you will depend on your specific situation, and it may take some trial & error to find the solution.

But as far as rancidity, using ROE+chelator is a good start to reduce the likelihood of your oils in your soap turning rancid. You also may need to reduce your superfat. I prefer less excess oil in my soap to go rancid, and I notice that a lower superfat in my recipes makes a fine soap, so I see no reason to use even the default 5% SF most calculators are set at. I will often make soap with a 1% to 3% SF and never end up with lye heavy soap by using these lower settings.
 
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Since I sold for years I always added Roe to my fresh oils upon opening them and used a chelator when making my soaps. During my last few years of soapmaking, my chelator of choice was a combination of EDTA and Sodium Gluconate at a rate of 0.5% each per total batch weight for a total of 1%. Prior to that, I used EDTA at a rate of 0.5% total batch weight. Prior to EDTA I used citric acid/sodium citrate but did not like the crystals that eventually formed on the outside of my soaps.
 

dibbles

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Prior to EDTA I used citric acid/sodium citrate but did not like the crystals that eventually formed on the outside of my soaps.
How long was it before you started seeing crystals forming? I’ve been using sodium citrate in (almost) every batch for 2-3 years (maybe longer) and have never seen this. I have a few soaps that have been sitting unwrapped on my curing shelf for at least 2 years from miscellaneous FO etc. test batches.
 
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