DOS question

[hyperhounds]

I made a bunch of soap back in the fall. Around October - November. I was checking on some of them and noticed the DOS on my Anise bars. All the other soaps seem to be fine. Is it possible the Anise essential oil caused the spots? I used distilled water, and a very basic recipe with palm, coconut, olive oil, and castor oil.

 

[topofmurrayhill]

It's possible. You could introduce DOS-causing contaminants via some adjunct ingredients. You can protect against that by using an antioxidant in combination with a chelator to inactivate any metal ions that get in. I would suggest EDTA plus ROE (rosemary oleoresin extract).

 

[hyperhounds]

thank you for the tip. Was is EDTA? Is it possible my essential oil was expired? i really like the small of Anise and would love to make more. But I don't want to risk ruining more batches. Would a new bottle be just as likely to cause DOS? Is Anise known to cause problems?

 

[Seawolfe]

I've never heard of anise to cause problems. I use star anise and lavender in some recipes and straight star anise in others and never saw any DOS. Where did you get your essential oil?

 

[cmzaha]

I also never have never had any problems with dos in Anise soap.

 

[hyperhounds]

essential oil is from Voyageur in BC. I'm thinking the DOS must be from something else. But I just can't figure out what. So frustrating. I followed all the must do's to avoid DOS and I still ended up with some.

 

[KristaY]

Last summer I made about 20 batches of soap using the exact same recipe and the exact same oils (same containers and/or batch numbers). All made in the same type of mold, using the same process, and all stored in the same environment. The ONLY variables were FO/EO and color. Out of all those batches, one developed DOS. I can't figure out what may have been different with that one that caused it. I ended up dumping all the bars in the trash and making a new batch duplicating the previous recipe. I watched them like a hawk and no DOS after 10 weeks so gave them as Christmas gifts and kept one (wrapped) to observe. It's now been 6 months and still no DOS. Sometimes it's easy to identify the cause and sometimes you have to brush it off and move on. DOS is a very elusive beast at times.

FYI - within all those batches of soap was an anise orange loaf. It wasn't the one that developed DOS. BB's Lavender & Herb colored with Nurture's Wisteria Purple was the bad boy in that round. Go figure.

 

[topofmurrayhill]

thank you for the tip. Was is EDTA?

EDTA is an additive that functions as a chelator. That means it binds with and deactivates the chemical properties of metals that might be dissolved in water. Metals can be very powerful in causing DOS.

Combined with an antioxidant like ROE, tetrasodium EDTA is a good precaution against problems. You can get it from suppliers like Lotioncrafter who sell cosmetic and B&B ingredients. You only need a tiny amount in your lye water, like about 1 gram for every 2 lb oils.

There is no problem with anise EO in general. You can keep using it. That is only one possibility for what could have caused the problem. Even if it did, that doesn't mean it was old or spoiled or in any way bad. We don't use tap water in soap because some of the dissolved minerals can cause DOS, but it's perfectly fine to drink.

Just a little contamination from certain metals can lead to DOS. It's educational to put soap in direct contact with iron, copper or brass and see it turn orange.