CPLS : Unpleasant odor

Lankan · Nov 26, 2018

the CPLS paste I made has an unpleasant odor. I initially thought that it may be due to the oils used (Palm,Coconut,Sunflower & Olive). The odor disappeared when FO was mixed. However, after a month or two the FO strength reduced and the odor appeared again. I only added FO in small % ( 2ml per 600ml of diluted solution (3:1 dilution)).

Is it normal to have such odor in the CPLS or can it be due to any of the oils used. Palm & Coconut oils are freshly out from the bottles and the other two bottles were opened about 2 months prior, however stored closed in a dark cabinet..

Obsidian · Nov 28, 2018

I have the same issue with liquid soap and the paste. It seems that after just a short amount of time, the paste starts to smell off. Doesn't matter what kind of oils are used, it just smells nasty. Mine is unscented though, I should try some FO and see if it helps.

Lankan · Nov 29, 2018

The FO that I added eventually faded off and the smell came back. I added 2ml of FO on 150g of paste diluted with 450ml of water. I didn't wanted to go for high concentrations as it may leave heavy stain of smell in the hands (we use this LS as hand wash).

My initial suspicion was on the sunflower oil (SFO) due to two reasons. the previous batch of CPLS which didn't have SFO did not have this smell. However that batch was defective due to water separation. The Bar soap which contained the SFO from the same bottle (together with palm & coconut oil) experiences some rancidity.

Now I'm confused and wonder what exactly wrong..

earlene · Nov 29, 2018

I think your answer lies in your last post. What is wrong is the sunflower oil itself.

Lankan · Nov 30, 2018

earlene said:
I think your answer lies in your last post. What is wrong is the sunflower oil itself.

Thanks, the leftover SFO in the bottle appears to be in good condition that even be used in cooking. I wonder how such thing can turnout bad on soap.

I'm planning to make both bar soap and LS in coming weeks. Let me try excluding the SFO, however already purchased castor oil, hope that won't introduce more problems.

earlene · Nov 30, 2018

Each different oil has an expected shelf life before it may start to go 'bad' or start turning rancid due to oxidation. Perhaps your sunflower oil is very near the end of or beyond that expected shelf life, which may lead to the off smell in your soap. Or perhaps your nose is more sensitive to the odor of sunflower oil in soap. Some people have stated they just can't stand the smell of olive oil in soap, while others never have that reaction. Some folks (me included) can't tolerate the smell of lard in soap. So it could be your nose, and not the actual oil itself. But sunflower oil does not have a very long shelf life, so I would keep that in mind. For soap with much SF, the shelf life of the oil can play a role in how fast a soap may start to go rancid.

Shelf life of soapmaking oils: https://www.soapqueen.com/bath-and-...s-guide-to-soapmaking-common-soapmaking-oils/