Only my peppermint CP soaps develop DOS!

[poramor]

I would be very grateful if some fellow member could help me with this dilema. I make 25 pound batches of cold process soap which I divide at light trace into four sub-batches with different essential oils and additives. The last sub-batch I work on is the simplest one, with only peppermint e.o. and no other additive. By the time I get there, sometimes the soap is way past trace. What I have noticed is that the only soap that sometimes develops DOS is this last one with peppermint. My question is, does DOS develop more easily because I put the soap in molds when it has become pretty hard or is the peppermint e.o. the culprit or what other cause could there be for this selective DOS? The main oils I use are palm, sesame and coconut with small ammounts of castor and olive and cocoa and shea butter.

 

[steffamarie]

I remember seeing that a high percentage of sesame can contribute to DOS - I don’t know how much you use, but it’s possible that is a contributing factor? I’ve seen people have issues with EOs and DOS before. I’m sure one of them will weigh in!!

 

[Obsidian]

Do you always use eo from the same supplier? Maybe try a different brand, see if that helps.
Being molded while thick wouldn't have any affect on dos.

 

[DeeAnna]

In my earlier soap making misadventures, I had direct experience with older lavender EO and mint EOs being triggers for all-over rancidity.

I've had several batches of soap with mint EO do really strange things after a couple of months of cure and storage -- slimy, smelly, color change, the whole rancidity thing.

I'm sure the sesame could contribute to the development of rancidity, but I've never tried it. What I can say without a doubt that these EOs can be troublemakers. The use of an antioxidant and/or a chelator would probably be helpful, but I'd not give any guarantees that these additives would be a surefire fix.

I've become so leery of these 2 EOs that I don't know if I've made soap with either EO since I started to use ROE (antioxidant) and EDTA (chelator.) I'd have to look at my files to see.

 

[NsMar42111]

Yep, I can't get a decent mint (even EO) to not dos eventually. Ditto on lavender....

 

[HowieRoll]

This is very timely, because recently I've had issues with soaps that include peppermint EO getting DOS. In fact, different batches of soaps made the same day with the same ingredients (except the EO blend) have had different results - the ones without peppermint EO have been fine, while the ones with peppermint have gotten those frustrating little orange dots, and within just a few weeks of being made.

I recently purchased another order from New Directions Aromatics, where I get most of my essential oils, and included in that was a fresh bottle of their peppermint supreme EO. When I opened it up and compared the smell of it to the old bottle (purchased in late 2017), there was a subtle but noticeable difference in the smell. The thing is, the older bottle smelled just fine and minty on its own and I would have never been able to tell it was a bit "off" without having the new bottle to compare it to. This makes me wonder how many of my other EOs might be going 'round the bend, as it were, but I might not be able to tell.

The other day I made a batch of soap slightly larger than normal, poured off a couple ounces of batter to be scented with 5% of the 2017 peppermint EO and put that into individual molds (uncolored). The rest of the batch was scented with the new peppermint EO and patchouli. Now it's a wait and see, although I suspect the 2017 peppermint EO soaps will start to turn orange soon.

Sorry, this is all a long-winded way to say that I feel your pain, although a big batch of soap for me involves 28oz of oil, not 25 lbs. I'm beginning to think that any peppermint EO I buy needs to be used in a relatively short period of time after opening the bottle to avoid issues.

 

[DeeAnna]

Lavender EO can have the same shift in scent. The oxidized EO smells faintly rancid to me -- the rancid undertone is pretty much the same stale, sour smell that rancid cooking oil or rancid soap has.

I agree, @HowieRoll, if you don't have some experience with how a given EO should smell, however, it would be very easy to miss the difference.

 

[nonna oakie]

Does this work the same with f.o.?

 

[DeeAnna]

@nonna oakie -- Are you asking about the change in scent as the fragrance gets older? If so, yes, FOs can change scent too.

 

[nonna oakie]

I was wondering if spearmint/mint f.o. would do the same dos problem in c.o. batter as the e.o. I use f.o. only.

 

[Obsidian]

I use peppermint fo from natures garden and have no issues with dos. It sticks better than eo and imo, smells nicer.
Same with lavender, I've went to a fo with better results.

 

[nonna oakie]

GREAT

 

[MKLonestar]

I use peppermint fo from natures garden and have no issues with dos. It sticks better than eo and imo, smells nicer.
Same with lavender, I've went to a fo with better results.

I, too, switched over to the peppermint FO and the lavender FO because they smell nicer and hold their scent well after cure. Natures Garden has probably the best for these two FO's that I have found so far. I have bars that are from early (January) 2018 and they are both still holding their scents that were used with the NG FO's, however, a peppermint from another supplier isn't doing so well and it is on the curing rack right now (same recipe, just different FO supplier), all I can hope for is that the scent will return as it cures.

 

[shunt2011]

I too use the peppermint and Lavender Flowers from NG.

 

[soapmaker]

From the beginning of my soaping days I had trouble with any soap with Lavender or Peppermint in them. The scent would disappear in a few months followed by an orange spot. That's how I learned about DOS. My remedy was a bit of ROE in every batch with these two e.o. s Fixed the problem for me. More recently I've added a small amount of NG's Lavender Flowers to the e.o. which I learned from shunt will make it stick longer. NDA's Peppermint Supreme is indeed supreme to me and ROE keeps it smelling supreme.

 

[lenarenee]

Eo's like lavender, mints and rosemary contain similar constituents. Lavender is known for causing dos pretty quickly so I'm not surprised that peppermint might also. I make a lot of lavender, but only a few peppermint or spearmint and did suspect peppermint went bad fairly quickly.