Yet another post on DOS...

[LilianNoir]

Ok.. but hear me out.

I was transferring soaps from inside my soap island(limited space, among other things) to plastic containers to put in my linen closet and discovered two bars from a batch I made last year had little orange spots. That makes a total of three batches now that have developed DOS. But in each case the DOS spots were just that: small, discrete spots that didn't "spread" and were on 2, maybe 3 bars at most.

Now I KNOW the main factors that can cause DOS: metal contamination, old oils, sunlight/UV, and heat.

So, what explains a few, small, discrete DOS spots that don't smell bad, occurred on 2-3 bars, across three different batches that didn't share EO/FOs, color, or unsaturated oils. All three batches used fresh oils and distilled water.

I can't figure out the cause and it's driving me batty. I don't want this to continue but I can't stop it if I don't know what's causing it.
additional details:

Out of a total of 13 cold process batches I've made, the DOS has shown in three. Other non-DOS batches shared the same source oils and equipment.

None of the batches with DOS had unsaturated oils in common, but they DID share the same source of shea butter, which is/was UNREFINED. I thought maybe that had some metal contamination in it, but I made other batches with that shea butter that show no sign.

All three batches were soaped a bit hot. Batches made when I started soaping cooler don't have DOS (so far).
Batch 1: lye 107F, Oils 127F
Batch 2: lye 86, Oils 126F(that was a bit of an experiment in temperature difference)
Batch 3: I don't have notes on temps but I recall this one setting up MUCH more quickly than I anticipated and I'm pretty sure my temps were higher. I also got glycerin rivers in areas that had TD. Probably around 120F for oils.

All oils were fresh. Batch 1 was literally my very first batch.
I always use distilled water.
Batch 1 was unscented, uncolored. Batch 2 used mint and lavender EOs, uncolored.
Batch 3 used several different FOs and micas, DOS appeared in the bottom half (which used different FOs than the top).

Batch 1 was set on coated wire racks in my kitchen pantry (away from any food). I thought since the rack was coated it would be ok, and in fact one of the bars seemed to develop dos where it was laying on the rack. This was the only batch to have orange that a little more than a spot.
Batch 2 and 3 were stored on plastic mesh, on top of (different and new) powdered coated racks, kept inside my "soap island". The spots that developed on these bars were on the cut face of the soap which did NOT come in contact with the rack in any way. The spots were small, limited to one spot per bar, and 2-3 bars total.

None of the bars with the DOS smelled off in any way, including the unscented one.

The only other common factor is that I keep my soap island near my pantry, and both are near a large window. The bars/batches did NOT get exposure to sun, but I think that through the day that area of the kitchen does get warm, up to 80+ degrees.
At the same time, I started keeping other batches at the very TOP rack of my pantry, on paper (so no exposure to the metal) and those didn't see any DOS.

I also didn't use gloves to handle those batches as they were early batches and I wasn't going to sell them or anything.

So I can't really find many commonalities, but three batches out of 13 isn't great.

So my thoughts are:

• metal contamination, but from where? If so, wouldn't all batches have it?
• contamination from hands?
• Unsat oils getting too warm in storage(they are in the pantry as well, but again if this were true wouldn't all soaps that use these oils be affected and wouldn't it be more widespread than a few discrete spots?)
• soaps getting too warm during curing (again, other soaps kept in the same area)
• hot temps during soaping, PLUS metal contamination?
  
  the last one seems most likely.
  
  In the meantime, I have relatively new containers of unsat oils and have added ROE to all of my unsat oils. I'm keeping unsat oils in the fridge now.
  I've moved all soaps to plastic containers, and am keeping some of them in a linen closest in the coolest area of the house. Unfortunately, I don't have much room there, so the remaining soaps are in plastic containers at the top of the kitchen pantry (where I had batches sitting on paper there with no issue).
  
  I've started using gloves ANY time I handle soaps. I'm considering also adding in chelator (sodium citrate), which will also help prevent soap scum since we do have very hard water here. (Maybe contamination from water on my hands when touching?)
  I just don't want to use additives to somehow cover up a mistake that I shouldn't be making.
  I'm careful in my environment and keeping equipment clean and cleaning it before using it. I don't understand why I've had this problem three times now, and other folks never seem to have it at all.
  
  To be fair, Batch "3" was made a year ago was my 5th batch of CP soap, and none of my batches made since then have developed DOS, even before I added ROE. So I'm really wondering if my higher temps in those batches contributed. But I'd love to hear from others with more experience because not being able to find the cause of a problem is driving me nuts.
  
  
  ETA: All recipes used a 5% super fat

 

[DeeAnna]

• metal contamination, but from where? If so, wouldn't all batches have it?

No, not all batches or bars will get DOS, because metal contamination that causes DOS is random.

• contamination from hands?

Certainly could be. I make sure to handle my soap with freshly washed hands. It could also be dust particles or air pollution. Or the use of tap water rather than distilled. Or metallic bits from equipment used to harvest and process the foods from which the fats come. Or metal soap making tools. Lots of sources. Rancidity and DOS | Soapy Stuff

• Unsat oils getting too warm in storage(they are in the pantry as well, but again if this were true wouldn't all soaps that use these oils be affected and wouldn't it be more widespread than a few discrete spots?)

Yes, in this case the rancidity would be more widespread, IMO.

• soaps getting too warm during curing (again, other soaps kept in the same area)

Any reasonable room temperature environment should be fine for curing soap. It never hurts to cure in a cool, dark, dust free, yet well ventilated environment.

• hot temps during soaping, PLUS metal contamination?..."

I wouldn't go crazy trying to reduce temps for the DOS problem you're describing. Frying oils do break down and oxidize due to exposure to water, oxygen, and high temps, so this kind of situation isn't the best for soap either. But what you're talking about here sounds to me more like rancidity triggered by particles of contamination, not overall oxidation due to exposure to water, oxygen, and high temperature.

It sounds to me like you're trying to nail down the cause of DOS so you can absolutely eliminate it. That's not going to happen. You can minimize the chances of DOS by good hygiene, distilled water, avoiding obvious metallic contamination, storing in cool dark conditions, and all that, but you will never be able to fully control all sources of contamination.

That's where the use of a chelator comes in. Once I started to use a chelator in my soap (in addition to good soap making hygiene and all that), the incidence of DOS and overall rancidity in my soap has become much lower. Not zero, but very rare. EDTA and sodium gluconate and citrate are the three options a lot people are using according to what is said here.

 

[cascarral]

• metal contamination, but from where? If so, wouldn't all batches have it?

No, not all batches or bars will get DOS, because metal contamination that causes DOS is random.

• contamination from hands?

Certainly could be. I make sure to handle my soap with freshly washed hands. It could also be dust particles or air pollution. Or the use of tap water rather than distilled. Or metallic bits from equipment used to harvest and process the foods from which the fats come. Or metal soap making tools. Lots of sources. Rancidity and DOS | Soapy Stuff

• Unsat oils getting too warm in storage(they are in the pantry as well, but again if this were true wouldn't all soaps that use these oils be affected and wouldn't it be more widespread than a few discrete spots?)

Yes, in this case the rancidity would be more widespread, IMO.

• soaps getting too warm during curing (again, other soaps kept in the same area)

Any reasonable room temperature environment should be fine for curing soap. It never hurts to cure in a cool, dark, dust free, yet well ventilated environment.

• hot temps during soaping, PLUS metal contamination?..."

I wouldn't go crazy trying to reduce temps for the DOS problem you're describing. Frying oils do break down and oxidize due to exposure to water, oxygen, and high temps, so this kind of situation isn't the best for soap either. But what you're talking about here sounds to me more like rancidity triggered by particles of contamination, not overall oxidation due to exposure to water, oxygen, and high temperature.

It sounds to me like you're trying to nail down the cause of DOS so you can absolutely eliminate it. That's not going to happen. You can minimize the chances of DOS by good hygiene, distilled water, avoiding obvious metallic contamination, storing in cool dark conditions, and all that, but you will never be able to fully control all sources of contamination.

That's where the use of a chelator comes in. Once I started to use a chelator in my soap (in addition to good soap making hygiene and all that), the incidence of DOS and overall rancidity in my soap has become much lower. Not zero, but very rare. EDTA and sodium gluconate and citrate are the three options a lot people are using according to what is said here.

Hello DeeAnna, I read tour article and have a couple of questions: Do trace minerals in clays can also contribute to DOS? and... You mention storing oils in glass or plastic and never metal, my EO supplier sends me the product in aluminium bottles, is this terribly wrong?

 

[LilianNoir]

It sounds to me like you're trying to nail down the cause of DOS so you can absolutely eliminate it. That's not going to happen. You can minimize the chances of DOS by good hygiene, distilled water, avoiding obvious metallic contamination, storing in cool dark conditions, and all that, but you will never be able to fully control all sources of contamination.

That's where the use of a chelator comes in. Once I started to use a chelator in my soap (in addition to good soap making hygiene and all that), the incidence of DOS and overall rancidity in my soap has become much lower. Not zero, but very rare. EDTA and sodium gluconate and citrate are the three options a lot people are using according to what is said here.

Yup, you're right on all accounts.
I think, overall, I'm good with many of the methods to minimize DOS (using distilled water, avoiding metal containers and obvious contamination, storing in cool, dark conditions - while I was afraid my store space was too warm, I checked over this week and it never got about 82 so not "cool" but not hot either)
and that's what was driving me nuts.

Where I need to be better is using gloves to handle soap. Previously I was, as you were, washing my hands before, but since our tap water is so hard (you should see the residue left behind in the distiller!) even a bit of water from that might cause trouble.

Using a chelator is where my mind was going, so it's good to see that idea as the next logical step, affirmed.

So then, what to use?
I already use ROE, and I know that works well with EDTA, per Dunn.

My current base of friends that I give/"sell"(they insist on paying me) some aren't quite crunchy but prefer "natural" additives and I have plans to sell eventually, and I suspect that audience will be mixed as well. So I was thinking of using citrate instead. I also am not sure about some of the environmental concerns of EDTA.
I know Dunn didn't see a different with Citrate and ROE, but apparently at 2% other soapers have? Or was that only to combat soap scum?

I was reading about sodium gluconate, and that seems promising.
What do you use?

 

[GemstonePony]

I use sodium gluconate, and it's a product of the fermentation of glucose. "Natural" is always up for debate, but I believe it's more environmentally friendly than EDTA. I find it much more effective than sodium citrate/citric acid as a chelator. I use it at 2% PPO since my water is liquid rock and I tend to shuffle my soap around. I've never used EDTA, so I don't know how it stacks up in effectiveness to that.

 

[Dawni]

My very unscientific suggestion.. Based on something that happened to one of my soaps - one bar, out of a batch - is a small, solid contaminant that could have floated in and gotten on your soap.

I think I have a pic somewhere in the forum. I got one spot of orange on a white Castile soap on one bar and when I looked closely, something was stuck on it.

 

[DeeAnna]

I currently use EDTA but when I've used up what I've got, I'm switching to sodium gluconate. SG is much more biodegradable, but it appears to be as effective as a chelator as EDTA is. Citrate doesn't seem to be as effective as a chelator compared with the others and people sometimes report side effects such as a rubbery texture or an ashy appearance.

I've recently been updating the info I have on my website about about these chelators. Rather than regurgitate this stuff here, please see these articles -- Table of contents | Soapy Stuff

 

[LilianNoir]

I currently use EDTA but when I've used up what I've got, I'm switching to sodium gluconate. SG is much more biodegradable, but it appears to be as effective as a chelator as EDTA is. Citrate doesn't seem to be as effective as a chelator compared with the others and people sometimes report side effects such as a rubbery texture or an ashy appearance.

I've recently been updating the info I have on my website about about these chelators. Rather than regurgitate this stuff here, please see these articles -- Table of contents | Soapy Stuff

I was looking at various posts about SG because I had some doubts as to citrates effectiveness at preventing DOS. I think I'll be trying out SG as well.
I had read through all of your articles too, thanks for reposting the link. I find your site to be one of my first "go tos" for info.

And thanks for replying. You're a treasure.

I use sodium gluconate, and it's a product of the fermentation of glucose. "Natural" is always up for debate, but I believe it's more environmentally friendly than EDTA. I find it much more effective than sodium citrate/citric acid as a chelator. I use it at 2% PPO since my water is liquid rock and I tend to shuffle my soap around. I've never used EDTA, so I don't know how it stacks up in effectiveness to that.

Ah thank you for this!(and I owe you a message!) I agree re: the term natural. I'm more concerned with how environmentally friendly something is.
It's also good to get confirmation from multiple sources on the use of something. I think I'm going to try it!

Where do you get yours?

 

[GemstonePony]

Ah thank you for this!(and I owe you a message!) I agree re: the term natural. I'm more concerned with how environmentally friendly something is.
It's also good to get confirmation from multiple sources on the use of something. I think I'm going to try it!

Where do you get yours?

Amazon. I haven't looked for it anywhere else, but I haven't seen it while rummaging through my main soap supply websites for other stuff either.
ETA: if you do happen to find it somewhere else, please let us know. I like having back up sources, and if I could bundle it with my other soap supplies that would be great!

 

[DeeAnna]

Save On Citric -- Search

 

[AliOop]

I was just going to suggest Saveoncitric.com, as well. They have good prices on all kinds of stuff, including SL, CA, SG, preservatives, stuff for making shampoo bars, and even sodium metabisulfate (which @Todd Ziegler is using for homemade VS experiments as we speak).

 

[GemstonePony]

I had not heard of Save on Citric before. Thank you for expanding my resource horizons!

 

[DeeAnna]

I'm leery of buying chemicals on Amazon unless I verify the supplier I'm buying from. There are too many reports of less reputable sellers somehow getting their products included in the same listing as reputable sellers' products. You don't always know who you're buying from if you click the "add to cart" button without researching.

I do sometimes buy from Amazon, even with this risk. For example, Wholesale Supplies had a very good sale on NaOH in Amazon that wasn't listed on their website. I verified I was buying from WSP and went ahead with the purchase through Amazon. (And crossed all my fingers and toes!) It went fine.

 

[Todd Ziegler]

Save on citric and make your own are operated by the same company. They very just a little on each website but they all come out of the same warehouse.