I hate DOS!

OK, I give up!

After some success a few months back making CP I started to get DOS on almost every batch.

Read almost everything I could on here and looked back at my recipes and oils and came to the conclusion it could have been old oils or it may have been an affect of using EOs.

So, changed my oils, checked the new ones were in date etc. Changed the formulation from standard CP to room temperature and made a few batches including one uncoloured and fragranced as a test/control batch.

Everything went well, got the best looking, smoothest, neatest soaps I have ever made and left them to cure. Everything is fine for about four weeks and then all of sudden I seem to get DOS. It varies from the odd spot on one soap in the batch to the whole batch infected, including the unfragranced, uncoloured ones.

Which leaves me think the only other option must be my overall recipe. I have now tried to formulations and have had DOS on both so would welcome some advice.

Basic recipe in g
100 Shea
100 Caster
150 Olive
100 Coconut

168 Sodium Hydroxide
62 Water

Thanks in advance for any help you are able to provide.

Have you tried adding a little rosemary oleoresin to your soap? I always add a little Vit E and don't have trouble with DOS, but according to some it has little value, so maybe I have just been lucky. You might try storing your soap in a drier area. I store my soap in my basement craft room, but I have a dehumidifier going in there.

I'm pretty new at this yet, and I can't speak from experience because I've never had DOS, but I'm seeing a couple things right off the bat. 1) That can't be the right amount of lye you used is it?? I'm assuming you flip flopped your water and lye numbers, then you'd be good. 2) As far as the DOS goes, I'm guessing it's the castor oil. Most people only add it up to about 5%, although I think some go a bit higher than that. But you are above 20%.

Maybe that's not the reason though. The experts should be around shortly.

gdawgs said:

I'm pretty new at this yet, and I can't speak from experience because I've never had DOS, but I'm seeing a couple things right off the bat. 1) That can't be the right amount of lye you used is it?? I'm assuming you flip flopped your water and lye numbers, then you'd be good. 2) As far as the DOS goes, I'm guessing it's the castor oil. Most people only add it up to about 5%, although I think some go a bit higher than that. But you are above 20%.

Maybe that's not the reason though. The experts should be around shortly.

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Oops yes of course! They are round the wrong way - should be 168 water and 62 lye D'oh!

I wondered about the caster - I thought it might be the culprit a while back so I changed it out to a new supplier and bought a brand new fresh batch. You think the %age may be too high then?

What are you storing your soaps on? If it's metal that could be a problem. I also agree that 20% Castor is too much. Most use between 5-10%. Too much can make sticky soap.

shunt2011 said:

What are you storing your soaps on? If it's metal that could be a problem. I also agree that 20% Castor is too much. Most use between 5-10%. Too much can make sticky soap.

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Used to store on metal but changed that too, they are now stored on a board on to top of a wooden rack on top of a wardrobe/cupboard.

The thing is the DOS isnt on every soap and every batch and the soap itself is really hard, especially when its cured for 4-6 weeks. Is the general view is that the caster should be about 50g max?

Too much Castor. Too high a SF / lye discount.
I never use more than 7% castor and usually keep it to 5 %. You are using 22.2%!
Your superfat is running 36%! I am not surprised you are getting DOS with that high a SF. I run SF as high as 20% in salt bars, otherwise I keep it around 5%.

Please run your recipe through a lye calculator (like soapcalc) and try less castor and a lower superfat. That should help you not have DOS.

From what I've seen, I don't think hardness and DOS are specifically related. If soaps higher in the linoleic-linolenic oils tend to be softer for you and you're noticing more DOS in those soaps, you might think softer soap -> more prone to DOS. But in that case, it's probably more about the linoleic-linolenic content in the recipe, not the physical softness, that is the problem.

If you are getting spots of DOS here and there, I'd look at something in that is adding bits of metallic contamination. In particular look for metal specks from tools or from storage on metal. If you are storing your soap directly on wood, be aware that wood is usually planed flat with metal knives and invisible flakes of metal can embed themselves in the wood from the planing process. I prefer to use plastic or well washed cotton toweling. Using distilled or demineralized water to make your soap can prevent bits of metal contamination from water. Handle with clean hands. Keep soap covered while curing and package in such a way to minimize dust and other contamination.

Overall rancidity where the soap turns more or less orange-rust over the whole surface is more related to an ingredient mixed into the whole of the soap. One possibility is rancid oils. Another is the use of an essential oil that is oxidized (old lavender EO is a culprit). But if you're not seeing overall rancidity, I'm not sure I'd worry too much about rancid or oxidized ingredients.

Using a chelator such as citrate or EDTA has eliminated DOS spots for me. I use ROE as well but it guards against oxidation/rancidity of the oils. IMO, ROE doesn't control the bits of metallic contamination that cause DOS spots.

Edit: Is there a typo in this recipe? Looks like the water and the NaOH weights are reversed. With 168 g NaOH, you have WAY too much. With 62 g NaOH, that's about 3% superfat.

From your first post --
Basic recipe in g
100 Shea
100 Caster
150 Olive
100 Coconut

168 Sodium Hydroxide
62 Water

DeeAnna said:

From what I've seen, I don't think hardness and DOS are specifically related. If soaps higher in the linoleic-linolenic oils tend to be softer for you and you're noticing more DOS in those soaps, you might think softer soap -> more prone to DOS. But in that case, it's probably more about the linoleic-linolenic content in the recipe, not the physical softness, that is the problem.

If you are getting spots of DOS here and there, I'd look at something in that is adding bits of metallic contamination. Metal contamination can be an issue -- in particular look for metal specks from tools or from storage on metal. If you are storing your soap directly on wood, be aware that wood is planed flat with metal knives and invisible flakes of metal can embed themselves in the wood from the planing process. I prefer to use plastic or well washed cotton toweling. Using distilled or demineralized water to make your soap can prevent metal contamination from water. Handle with clean hands. Keep soap covered while curing and package in such a way to minimize dust and other contamination.

Overall rancidity where the soap turns more or less orange-rust over the whole surface is more related to an ingredient mixed into the whole of the soap. One possibility is rancid oils. Another is the use of an essential oil that is oxidized (old lavender EO is a culprit). But if you're not seeing overall rancidity, I'm not sure I'd worry too much about rancid or oxidized ingredients.

Using a chelator such as citrate or EDTA has eliminated DOS spots for me. I use ROE as well but it guards against oxidation/rancidity of the oils. ROE doesn't control the bits of metallic contamination that cause DOS spots.

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Thats interesting as it is random here and there; just reviewed my records and two batches made on the same day four weeks ago have the odd DOS here and there but the batches made on days either side appear clear.

The contamination aspect does seem to make sense, might be as well to try replacing my tools and see if that gets rid of it. I am pretty sure the ones I had a few months ago were as the result of poor oils as they were spotted on every side of every batch and I had a similar issue with a couple of EO batches hence changing my oils and making a control batch.

I have just asked my son to inspect every batch and without prompting he asked what they had in them as he said it looked as if they had been contaminated so maybe that is indeed the culprit.

Steve85569 said:

Too much Castor. Too high a SF / lye discount.
I never use more than 7% castor and usually keep it to 5 %. You are using 22.2%!
Your superfat is running 36%! I am not surprised you are getting DOS with that high a SF. I run SF as high as 20% in salt bars, otherwise I keep it around 5%.

Please run your recipe through a lye calculator (like soapcalc) and try less castor and a lower superfat. That should help you not have DOS.

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She had the water and superfat listed in wrong order. It is actually around 3.5% superfat. Since I have never used that high a castor percentage I cannot address the possibility of it being the castor. My first thought was unmixed in fragrance, but mentioned it happened with the control un-fragranced un-colored.

Are you using any botanicals in the soap such as oatmeal, fresh aloe etc? I have trouble with lard and dos so I use 0.1% BHT and .5% EDTA in all soaps now. Stopped Dos. I used to use ROE, but the BHT works better for me, and lard already contains it so I am not really adding in a new ingredient, just a bit more

As someone who regularly uses high amounts of castor in 2 of her formulas (20% and 23% respectively) without any DOS problems, I suppose you can color me highly skeptical that castor could be the culprit. I've actually found castor to be a fairly long-lasting, hardy oil, which is not surprising to me since it contains a very low amount (4%) of only one of the fatty acids prone to causing DOS. My 2 formulas that contain the high amount of castor are not soft or sticky at all, but then again, they both also contain a very high amount of stearic to balance it. As I always like to say when using an inordinately high amount of any given oil that may otherwise cause yucky/unwanted qualities in someone else's soap: "Formula, formula, formula" (much in the same way that real estate sellers are fond of saying "Location, location, location". Formula is everything.


IrishLass

Nope not using any botanicals and although some of the batches are coloured with oxides the control batch had only the ingredients listed and no additions whatsoever.

I am leaning more and more towards contamination as its so random - if every batch had DOS I would assume it was either oil related or recipe related. The fact that of the ten batches I have now curing only two have random DOS makes we indeed wonder if I am introducing some kind of contaminate inadvertently - especially as the worst two are the ones made on the same day and the ones on days either side are perfect!

As far as caster is concerned, have made it like this for a while and originally didnt get any DOS at all - as soon as I started to get some I replaced all the ingredients with fresh from reputable soap suppliers just to be on the safe side.

Early on in my soaping misadventures, I had one batch of soap go totally rancid -- the bars turned completely yellow-orange and got that typical funky musty smell. One half of the batch was scented with older lavender EO, and those bars went rancid within a couple of months after making. The second half was scented with peppermint EO and those bars went rancid a few months later. The overall rancidity had to be from the fats, although there was no way I could pinpoint the exact culprit by the time I realized there was a problem. The acceleration caused by the lavender EO was an eye opener.

After that time, I never got this overall DOS, but I still got spots of DOS here and there -- not a lot, but not zero. I worked at reducing sources of contamination in the soap making process including replacing as metallic utensils to silicone or other lye-safe plastics as much as possible. I tried to correlate DOS with ingredients, recipe, superfat, and equipment I used without a lot of success. For example, I was sure for awhile that sugar was a trigger ... and then I realized it wasn't when several batches with sugar were fine and some without sugar got spots of DOS. And so on. I realized at least some spots of DOS might be inevitable because metallic contamination can come from many sources that I don't have any control over. I investigated the spots themselves -- do they typically spread or get worse over time, can a DOS spot "infect" other soap that might be touching the spot, does removing the spots stop the rancidity, etc. Eventually I discovered chelators and started to use EDTA with very good results. I also practice good "soaping hygiene" when making the soap and handling the bars afterwards. Even though EDTA is helpful, I prefer to think of it as insurance -- not a cover-up for sloppy habits.

LilyJo said:

OK, I give up!

After some success a few months back making CP I started to get DOS on almost every batch.

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You are using distilled water, yes?

topofmurrayhill said:

You are using distilled water, yes?

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No, bottled water.

But if that is the cause wouldnt all the batches be infected the same? And wouldnt all the same batch get DOS?

LilyJo said:

No, bottled water.

But if that is the cause wouldnt all the batches be infected the same? And wouldnt all the same batch get DOS?

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Maybe not, but I don't know for sure because I never tried.

What kind of bottled water is it? What does it say on the label?

You would want to use a type of water that doesn't contain minerals. For some drinking waters they actually add minerals for flavor. Some minerals are extremely effective catalysts for oxidation.

Ok, have now checked all the batches of soap that were due to finished curing in August (they have had six weeks) and the DOS does indeed appear to be confined to the two batches made on the same day and no others.

I am leaning more and more onto the theory that this is simply contamination - all the other batches have cured nicely with no evidence of any DOS whatsoever. My previouls experience goes back to a less than perfect oil and it seems that soaps made before and after are fine.

So, that being said I would be really interested in what you all do to avoid/reduce contamination. I have been making using the RT method and using a standard food processor to mix which has a metal blade (which is where I believe the contamination came from).

Lots of lessons learnt but all in all I am mightily relieved that it may come down to something completely resolvable providing I avoid any cross contamination in the future.......fingers crossed!

LilyJo said:

Ok, have now checked all the batches of soap that were due to finished curing in August (they have had six weeks) and the DOS does indeed appear to be confined to the two batches made on the same day and no others.

I am leaning more and more onto the theory that this is simply contamination - all the other batches have cured nicely with no evidence of any DOS whatsoever. My previouls experience goes back to a less than perfect oil and it seems that soaps made before and after are fine.

So, that being said I would be really interested in what you all do to avoid/reduce contamination. I have been making using the RT method and using a standard food processor to mix which has a metal blade (which is where I believe the contamination came from).

Lots of lessons learnt but all in all I am mightily relieved that it may come down to something completely resolvable providing I avoid any cross contamination in the future.......fingers crossed!

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Are you using a food processor or a stick blender?

I wash everything well and then store in a bucket with a lid. I've not had any contamination that I'm aware of in almost 6 years. I've only had DOS twice and I was never able to figure out where it came from other than they were both high liquid oil recipes with a too high SF.

Sometimes I'll spray my spoons or things with 91% alcohol just because sometimes they are still a bit greasy from my less then stellar washing.

Its a food processor as a)Im using the RT method and b) the motor is better so it works better at the initial stage of mixing

I do RT all the time with a stickblend. Never tried the food procesor nor have I heard of anyone doing it that way. If you use if for other purposes it very well may be cross contamination. Hard to say.