Friday, November 14, 2014

The Dreaded Spots of the Orangeness!

Geranium Patchouli soap with DOS
So you've made a beautiful batch of soap and it is hanging out on the curing rack, evaporating out its water and whatnot. Over the next few weeks, you lovingly check on it and marvel at this wonderful thing you made.

And then you see it. An orange-colored spot - or maybe several spots - marring the pretty surface of your soap and seriously harshing your soap buzz.

What is this ugly plague that is plaguing your soap with its plaguey plague?

It's - dah, dah, DAH! - DOS. No, not the ancient computer operating system. 

Dreaded Orange Spots.

You may remember this Geranium Patchouli soap I made about 16 months ago. I still have some bars from that batch hanging around, and I went to grab a bar recently. I usually let the soap bars cure on my curing rack for 6-8 weeks and then store them in paper bags and it seems to work out just fine. This time, though, the bar I pulled out felt wet and beads of glycerin dew glistened on its surface. 

Handmade soap naturally contains glycerin, which attracts moisture from the air. Humidity can increase the likelihood of glycerin dew, and it can get awfully humid here in Louisiana. It was interesting that none of my other batches that were stored similarly developed the same issue. At any rate, I wiped the afflicted bars dry and let them hang out some more on the curing rack. Now the glycerin dew is gone, but the ugly rust-colored spot remains.

So what causes DOS? Oftentimes it is caused when oils are exposed to oxygen and oxidize, resulting in rancidity. Every oil has a shelf life and some oils have shorter shelf lives than others. DOS can appear at many points during a soap's life - during the cure time or months later, as was the case with my soap. Old oils or oils with short shelf lives may contribute to DOS. And it's sometimes difficult to know how long an oil has been sitting on a store shelf before you buy it. Get your oils from quality vendors that replace their oils frequently to ensure that they are as fresh as possible and pay attention to expiration dates. (To see a comprehensive list of oils and their properties - including shelf life - check out this Soap Queen post.) Some oils - such as canola, grapeseed, and sunflower oils - have a reputation for contributing to DOS, although I haven't soaped with any of those oils and therefore can't comment on my own personal experiences with them.

Oil storage is important. Some short-life oils are best kept refrigerated, and it's always good to store any oil in a cool, dark place away from direct sunlight. Another tip is to transfer oils to smaller bottles as you use them up so that there is less contact with oxygen and therefore less risk of oxidation. Some soapmakers also add antioxidants such as rosemary oleoresin extract (ROE) or Vitamin E to fragile oils to extend their shelf lives.

Higher superfat percentages can also contribute to DOS. "Superfat" refers to the amount of oils that do not interact with the lye and remain unsaponified and sorta free-floating in the finished bars. Most soapmakers factor in a small percentage of extra oil in their recipes to create a more nourishing bar of soap. Some soapmakers advise keeping superfat percentages to 5% maximum (with the exception of recipes containing all or nearly-all coconut oil, which need a higher superfat of up to 20%). I usually use a superfat of 7% in a typical recipe with no problems, but could it have been an issue in this batch? Or was it something else? Perhaps I should experiment with a 5% superfat.

Water is also another important soapmaking ingredient. It's a good idea to use distilled water since tap water may contain minerals that could oxidize and cause DOS.

The curing environment is also important. Let your soap fully cure in a cool, dry place with plenty of ventilation. During the curing process, water evaporates from the soap and the moisture needs to be able to escape. Wire racks are great for curing, just make sure that the metal is coated so that it doesn't rust - rust can exacerbate DOS. If your curing area is particularly humid, a dehumidifier may help.

What caused DOS in my case here? Dunno. Could have been the oils, humidity, storage issues, or something else. It seems that so many soapmaking problems remain mysteries even when potential culprits are identified. I can't point with certainty at any one factor or factors. Hopefully, though, I can better avoid DOS in the future by keeping these tips in mind.

So what should you do if your soap gets DOS? Don't panic. The spots are rather ugly and the soap may smell a bit off, but it is merely an aesthetic issue. I wouldn't want to sell or gift these bars with DOS because eww-gross, but they're still fine to use.

At about the same time I was cogitating on this post, Anne-Marie wrote a great one about DOS on the Soap Queen blog. And also check out this helpful post by David Fisher for more info on DOS.

Have you experienced DOS? What are your thoughts on what causes it and how to prevent it?

14 comments:

  1. You could always think of the DOS as a sunny spot in your lovely soap. :)

    Are you planning on teaching soap making because you do a fabulous job of explaining everything about soap making. It's no wonder you've got such a huge following.

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    1. That's a good idea, Monica! I'll think of my DOS spot as a bit of sunshine. That makes it a little easier to look at. :) And thanks for the kind feedback! I sometimes wonder if I'm explaining things well. I'm glad to hear that the post was helpful.

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  2. Grate info Jenny. So many complex tings can influence DOS generation. But you are right, it is esthetic aspect and you can still enjoy using this beautiful bar of soap.

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    1. Thanks, Gordana! I'm not totally sure what happened here, although I suspect humidity or my oils. These bars were the only ones that got glycerin dew and they're the only ones that have gotten DOS so far. I'll have to watch my other batches made with the same oils to see if they develop DOS. I'll still enjoy using this soap, though, even if it isn't as pretty as it used to be!

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  3. Your made a detailed and very well explained post, Jenny, as always! I also dealt with it, and the problem was an old sunflower oil. It's indeed something we all would like to avoid, but as you said, something we can't be sure abut the quality of the oils we buy so best is to buy them in small quantities or to use them asap...Thanks for this interesting info, I didn't even know it's called DOS :)

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    1. Thanks, Natalia! I'm glad that you enjoyed the post. I've heard that sunflower oil has a reputation for contributing to DOS. I wonder if some of my oils are old, too. I'll have to keep an eye on my other batches made with similar ingredients. I also thought it was interesting that this batch developed glycerin dew, which makes me wonder if humidity had something to do with it.

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  4. Oh 'dreaded' is such a good word for it. I know it's harmless but it doesn't half spoil the look of a lovingly crafted soap eh? Did it affect all the bars or just one or two? I've only seen it a couple of times among my batches - and only one or two of a batch, not the whole lot - and wasn't able to pinpoint the reason, but I hadn't soaped with those 'usual suspect' oils. I have recenlty experienced the glycerin dew too - due I think to the dampness in our new house when we moved in (fortunately now rectified!) I've yet to notice any DOS on those ones, but keeping an eye on them... Great explanation by the way - I'm bookmarking for future reference ;-D

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    1. Hi, Vicki! I've got four bars left from this batch and only two of those bars have DOS so far. I wonder if humidity was an issue, since this batch developed DOS and glycerin dew. Strange that none of my other bars from other batches got glycerin dew, though. Maybe there's something particular about the ingredients in this batch. I may also get rid of my older oils and start fresh with some new ones, too. Thanks for reading - I'm glad that you liked the post!

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  5. Well, it wouldn't be fun if there was not something frustrating, lol! I'm kidding, but I suppose we all experience DOS sooner or later. Luckily, it's not that often,so we can identify the culprit the most of times.
    This is a great article, Jenny, I'm sure newbies will be grateful for it. And yes, I'm sorry you had a good reason to write it. : -)

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    1. Thanks, Maja! On the bright side, I did at least get a blog post out of the whole DOS ordeal! This is the first time I've had DOS, but it probably won't be the last. I'm glad that the post was helpful!

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  6. You might want to put them off to the side and just keep an eye on them. I did this with a batch of Orange and Patchouli, all essential oils and later realized that it might just be the Patchouli discoloring the white part (not spots, more of a creeping browning of the white sections) of the bars. They all still smelled great and no whiff of rancidity. I, also, did a batch with Patchouli (eo's) and cranberry fig, same thing happened to the white part as with the Orange Patchouli batch. That's when I thought that it might not be DOS, but just the Patchouli e/o discoloring. I live in SE Louisiana and run a dehumidifier in the soap house all the time. Humidity definitely plays a factor with DOS. Just a thought, great post.

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    1. Hi, Lisa! Thanks for your comments. I've got four bars left from this batch and only two have DOS so far after 16 months. The discoloration isn't uniform at all, just the one big spot. I know what you mean about the humidity - I think it may have played a role here, too. Thanks for reading!

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  7. Regularly read your posts! They are excellent! Thank you!

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