DOS?

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dragonmaker

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I’ve never had DOS before in soap. Do you these two soaps have the Dreaded Orange Spot rancidity? They are the same recipe with different super fats as an experiment. They don’t smell strongly, but do smell slightly different from the other soaps. They also ended up with a bunch of air bubbles from my new mixer that the other soaps did not get. All stored on the same shelf indoors.
80% lard
20% coconut oil
Distilled water
Lye
EDTA dissolved in distilled water
One has 1% SF the other is 5%SF

the other soaps I made that day are fine. They don’t have lard in them.
 

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I’ve never had DOS before in soap. Do you these two soaps have the Dreaded Orange Spot rancidity? They are the same recipe with different super fats as an experiment. They don’t smell strongly, but do smell slightly different from the other soaps. They also ended up with a bunch of air bubbles from my new mixer that the other soaps did not get. All stored on the same shelf indoors.
80% lard
20% coconut oil
Distilled water
Lye
EDTA dissolved in distilled water
One has 1% SF the other is 5%SF

the other soaps I made that day are fine. They don’t have lard in them.
I cant say it's defiantly DOS? How long has your soap been curing? Did you use any EO / FO? Thinking it could be that?. I've got a non-verified theory. The Nose Knows' If it has a off scent could be dos...
 
Yes, how old is this soap? Could be DOS, or could be contaminants left in the individual molds from a previous batch. Example: a discoloring fragrance or oils not thoroughly cleaned out of the molds (particularly if silicone molds). So check the molds just to be sure.

DOS doesn't really smell strongly at the very start, so what you smell could be what you expect to smell, or it could be a hint of what's to come, or it could be something left in the cavity mold that clung to the new soap. Time will tell if it is DOS, because once started & if you leave it alone, it will progress. So isolate them while you observe.
 
That's indeed not a very long time to develop DOS. Also the occurrence in all of the lower corners (rectangular soap) or around the top (round soap) isn't quite consistent.
How thoroughly have you blended the oils/lye (just to an emulsion, or all the way up to thick trace)? Did you mix it inside the final moulds, or in another container and poured it in there afterwards?
Lard can have some rancidity issues at times. What was your source of lard?
 
I mixed in the frosting (cylinder) container, poured the first tiny batch into the rectangle cream cheese container, then mixed the second tiny batch in the frosting container and left it to cure.
I mixed past emulsion to trace. Not thick trace, though.
my lard was a local brand that has been sitting in my cupboard for 6 months. Is that too long for lard?
 
Thanks for clarification. I suspected that you had stirred inside the containers: on the rectangular bar, the spots are in the corners, where it can be very tricky to get everything incorporated evenly, Even a seemingly thorough mix with a silicone spatula might be not enough. Maybe some of the lard was stubbornly stuck to the walls and effectively increased superfat in these corners.

It was good that you included EDTA into your recipe, which (among other advantages) protects from DOS escalation by unavoidable metal impurities. But it is not an antioxidant by itself, for this it needs to be paired with ROE and the likes.

Factory-made lard is less likely to get rancid in short time than, say, self-rendered, but it still can happen. 6 months isn't “fresh” any more, and who knows how old it already was when you bought it. Some professionals are paranoid about rancidity, add ROE into all oils at arrival, and put them straight into the fridge or even freezer.

For now, I recommend that you generously scrape off the whole surface of the soaps, to remove anything remotely yellowish (as well as soda ash), and put the slivers into a tight jar. Your nose will tell you in a few days if this really is rancidity.
Closely watch the peeled bars if they develop spots and/or smell again over the next weeks, and (as always) avoid contact with metals. If you're in luck, it was a superficial issue from uneven mixing. Anyway, use them up in due time, and store them for no longer than necessary.
 
I did not mix the soap in the rectangle container. I mixed it in the cylinder container and poured into the rectangle container.

I’ll try cutting off the offending yellow.

how do you use ROE on a solid oil like lard? Melt the lard first? Does that damage the ROE? ROE is Rosemary oil??? Does that make the soap smell like rosemary later?
 
That's indeed not a very long time to develop DOS. Also the occurrence in all of the lower corners (rectangular soap) or around the top (round soap) isn't quite consistent.
How thoroughly have you blended the oils/lye (just to an emulsion, or all the way up to thick trace)? Did you mix it inside the final moulds, or in another container and poured it in there afterwards?
Lard can have some rancidity issues at times. What was your source of lard?
That's not exactly true. Depending on environmental factors of the soaper as well as how old the soaping oils are, soap can develop rancidity pretty fast.
 
I did not mix the soap in the rectangle container. I mixed it in the cylinder container and poured into the rectangle container.
Sorry, then I misread you. Good to know, but this doesn't really help us to understand what happened. Maybe it really isn't DOS? I don't know any more.
Stupid question: How is the superfat different in the two bars when they're from the same batter?

how do you use ROE on a solid oil like lard? Melt the lard first? Does that damage the ROE? ROE is Rosemary oil??? Does that make the soap smell like rosemary later?
You have to melt the lard for soapmaking anyway, and ROE is robust enough to survive usual soapmaking conditions. ROE is made from rosemary (but not the same as rosemary essential oil), and in concentrated form it'll smell like rosemary, but from this scent nothing carries over into the soap, given the crazy low usage rates.
 
I'm still not sure I fully get it. You said you “mixed it in the cylinder container and poured into the rectangle container”, and then you “made 2 different very small 1-bar soap batters.”
So you mixed the first in the round mould, poured it into the rectangular, cleaned the round mould, and mixed the second one there? And which is which?

That consequence regarding lard is a drastic, but effective one. No lard means no chance of lard causing DOS. Lard is definitely not the most robust oil wrt DOS, and if you made bad experiences with it once, you don't need to force yourself stay with it. Tons of fabulous lard-free recipes out there!
 
@ResolvableOwl I'm not sure where I've been unclear, but I have been typing responses in between dealing with screaming children, so it's possible I left something out as I've been distracted. I will try again.

On May 1, 2021 I made 4 small experimental batches of CP soap. The first 2 soap batters I made that day are numbered 18 and 22 respectively in my lab book. They are behaving just fine post-saponification (no DOS) and neither had lard in them. The 3rd and 4th soap batters I made that day are numbered 19a and b respectively. They were made as follows quoted from my lab book:

"19a: I poured melted 80g lard and 20g coconut oil into a plastic freshly washed cylindrical frosting container. I weighed out 1.4g of a 50:50 EDTA and distilled water solution and blended it into the melted oils. Then I weighed out 28g distilled water into a separate bowl that I had used for all other distilled water and lye solutions that day, then measured 13.76g NaOH (lye) crystals into my lye cup and slowly poured it into the pre-measured h2o. [So, I apparently was incorrect in previous posts where I went off memory and said 19a had 5%SF. According to my records it really had 8%SF]. Once the NaOH was fully dissolved in the water I poured it into the melted oils and EDTA mixture (I'm a rebel and decided not to wait for the NaOH solution to cool). I blended the tiny soap batter with a new stainless steel milk frother bought for the purpose of mixing small test batches. [On this 100g batch it added a ton of bubbles, but on batches 18 and 22 which were larger 300g batches it worked splendidly without incorporating extra air.] This batch took an irritatingly long time to come to trace. I think I read somewhere that lard takes a while to trace??? I'd love input if someone has experience with high-lard recipes and time to trace. Once I was satisfied that I had mixed long enough and it wasn't going to separate I poured the batter into my freshly washed rectangular cream cheese container mold. Scrape down and wipe out the cylinder frosting container in prep for the next soap batch.

19b: Methods same as 19a. Pour 80g melted lard, 20g melted coconut oil, and 1.4g EDTA solution into cylindrical frosting container. Blend. Measure 29.61g distilled water and 14.8g NaOH [makes 1%SF]. Combine. Blend hot lye solution into oils with milk frother. Wait an absurdly long time for trace. Leave 19b in frosting can mold so I can tell 19a and 19b apart by shape.

On May 26, notice orangey yellow edges on both 19a and 19b. May 27th reach out to soapmakingforum to find out if this is DOS or something else happening."

Is that clear enough? Did I leave anything out?

I have not been put off lard entirely. I see no point in discarding a perfectly good and economical triglyceride from all my recipes just because I used an older container of lard that I knew might be on its way out in the next few months and I was attempting to use it up to avoid going to the store for more. I've learned my lesson and might start storing more oils in the freezer. I have used multiple jars of multiple brands of lard in the past 2 years, and this is my first time having this DOS issue. My first ever lard bar made last year was lovely after a few months of curing. These DOS disasters were a SF preference test, a first non-goat milk soap test, and an EDTA test (as I've never used EDTA before...), not an oils test. 19a was supposed to be compared to my lard-and-milk soaps to see if I like how EDTA works with my hard water. 19b was supposed to be compared to 19a to see if I like high or low SF.

My conclusions based on further research, rereading my lab book, and y'alls input saying it looks like it looks like it could be DOS and that it is possible for very young soaps to go rancid, and even my children saying the orange soaps are starting to smell funny: I'll have to redo the test with some fresh lard next time the weather is nice enough for soaping outdoors. Also, I will look further into ROE and other (?) antioxidants...

Other wisdom/tips always appreciated.
 
Wow, that's a great documentation practice! And you addressed quite some points that could have needed clarification. Now I/we can better understand your background, as well as dispel some earlier possibilities.
With these extra information, I'm now quite sure as well that this is DOS. Sounds like an early stage of rancidity in the lard batch in question, carried over unnoticed into the soap. That's likely why the %SF doesn't make a difference, and explains the rapid deterioration. It also means that it is not a surface issue, but goes throughout the whole bar, so scraping off the surface is purely cosmetic and won't stop progress of rancidity (still worth a try if you want to tempt fate/for scientific curiosity).

Although DOS is disagreeable, it won't too much affect the general properties of the soap (lathering, skin feel). So if your goal is to refine your superfat opinions, it's good enough for that – but it's still a good thing to redo the whole with fresh lard, since you probably want to try your SF preferences after longer cure times than one month.

There are better lard experts than me (I don't use it). It appears as a general agreement that lard is, atypical for its fatty acid spectrum, really a slow-moving oil. 20% CO can make trace a bit quicker, but it's still not for the impatient. Increased temperature (there goes your rebellion!), accelerating EOs/FOs, sugar/honey, castor oil, and an increased lye concentration might help things to speed up.

ROE is said to pair well with EDTA as a antioxidant/chelator tandem. Other antioxidants are BHT and tocopherol/vitamin E, either of which aren't as convincing as soap antioxidants IMHO, but you're of course free to form your own opinion.
 
I make a 100%, 5% superfat lard soap for the local food pantry because I can get lard from a local farmer cheap. I also make 100% lard, 0 superfat for laundry butter. It takes forever to trace, a test of patience! After my first batch and stick blending forever, now I just blend to emulsion. Even that takes time!

I agree with the others that your old lard probably caused DOS. It may be the fatty acids decomposing or the lard was not rendered and cleaned well so there are small bits of meat in it that have decomposed.
 
One of our very experienced members almost consistently got DOS with lard, except for the Snowcap brand. She also found that for her to be able to make DOS-free lard soap, she had to adjust the recipe. Below are some links to posts she made on the topic of how she finally was able to prevent DOS with lard soap. (Her experience.)


https://www.soapmakingforum.com/threads/differences-in-lard-question.82285/#post-866782https://www.soapmakingforum.com/threads/edta-vs-sodium-citrate.80440/#post-857524https://www.soapmakingforum.com/threads/lard-and-tallow.81843/#post-860547https://www.soapmakingforum.com/threads/my-lard-based-soaps-going-rancid.81754/#post-859495
 
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