humidity and DOS

[sirtim100]

Hello all

I made my first batch of CP soap, left it in the mould for a couple of days, cut it and left it to cure. One or two of the bars are starting to show little orange spots (DOS?). I've looked on the forum about the issue and some members have commented that humidity can play a part in this kind of problem. That figures, given that I live in A Coruña, which is coastal, damp (to put it mildly) and not often hot. One solution people propose to mitigate this is a dehumidifer (expensive for my limited budget).

Are there any other options?

Any help very gratefully received

 

[DeeAnna]

You haven't said anything about the recipe, including any additives and fragrances. Rancidity (DOS) doesn't normally show up that fast. There may well be something else going on, but you'll have to give more information to give us some clues. A picture would also be very helpful.

 

[sirtim100]

Olive Oil - 7.5 oz
Coconut Oil, - 6.5 oz
Almond oil - 6.5 oz
Castor Oil - 1.3 oz

Proportion of lye taken from soapcalc (can't remember exact amount because recipe wasn't saved, same with water). I used almond instead of palm because that's what was on hand at the time, and it was recommended as a substitute.

EOs: 2 oz (lavender, sweet orange and a few drops of frankincense)

I'll try and send a pic some other time, right now I'm working and the deadline's a tough one.

Best
Tim

 

[DeeAnna]

It's possible the EOs are discoloring the soap, especially if they aren't mixed into the soap batter really well. Orange EO is amber colored -- about the same color as DOS spots.

Sometimes beginning soap makers are instructed to add scent in at trace, and they may not get it mixed in well enough at that stage of the game. For well-behaved fragrances, I recommend adding the scent with the fats before the lye solution is added. That way there's less chance of forgetting and better chance of getting everything well mixed.

In addition to this, I haveta say you used a LOT of fragrance for 21.8 oz of fats. I would normally use no more than 1.3 ounces for a batch this size (6% based on weight of fats). In my experience, a high % of fragrance increases the chance the fragrance will weep out of the soap, even if well mixed.

 

[sirtim100]

Many thanks, DeeAnna, I think you've found the source of the problem.

I've got 11 bars curing right now, and only one shows orange markings on the surface. All the rest are sitting there, happily blemish free, despite the weird weather over here (hot and humid). So I reckon it's just as you say, one of the bars got an excess of sweet orange EO and it's showing up as a stain.

The % of fragrance was recommended in the recipe, in fact it said to put in even more, but I poured in less. Even to my untrained eye it looked like a lot for a bar of soap. I'll bear your recommendation in mind and stick to 6% for the next lot. Likewise for when to pour it in.

Thanks again
Tim

 

[DeeAnna]

The problem with following someone else's recipes is that you're taking their word that the recipe is accurate. It sounds like the author of the recipe you followed was giving bad advice.

Based on this example and from the experiences of many people who ask for help here on SMF, I think this is a risky assumption to make. Even the best of soap makers and authors sometimes make mistakes ... and the bad ones give downright dangerous advice on a regular basis.

I always recommend running any soap recipe through a recipe calculator to check the author's math. Two good ones are --

https://www.soapmakingfriend.com/soap-making-recipe-builder-lye-calculator/
http://soapee.com/

This will prepare you also for creating your own recipes rather than relying on other people's recipes.

Another thing too is to learn about the recommended dosages for various essential oils (EOs) and fragrance oils (FOs). You don't want to use 6% rate for any random EO or FO. Some are skin safe only at very low dosages (clove, for example) and others are skin safe at higher rates.

 

[sirtim100]

I'm aware that certain EOs are to be used with caution, I've been using EOs for other purposes for some time now.

What surprises me is that some recipes could entail an element of risk. Just goes to show. The Internet, best managed with a pointed stick at times.

Thanks again for the links. I'm already using the soapmaker friend site, and the other one looks very interesting.

Must go, I have some tallow on the hob...

Best
Tim