Rancid Smell

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

robcarr

Member
Joined
Jun 23, 2017
Messages
21
Reaction score
8
Hi!
I am new to soap making. I am doing the hot process soap making.
I have done three batches but all have come out with a rancid smell.
What am I doing wrong?:headbanging:
 
First thing, you should share the recipe you're using so the experienced folks on here can see if that's part of your trouble.

Have you checked your oils and butters? If one of them has gone rancid it should be tossed and replaced. Can't undo rancid oil. My next thought would be to check the temps you're soaping at. Too hot and you can scorch your oils, which might also result in a rancid smell. Third thought would be to ask what else you're putting in your soap- colorants, fragrances, etc. Lots of soap add ins smell pretty funky while the soap is cooking.
 
Thank you for your prompt answers and please, excuse my lateness in replying to your posts.
I am using 15 oz of organic coconut oil, 10 oz of castor oil, 6 oz olive oil, 5 oz stearic acid, 8 oz sugar, 5 oz of water, 4 oz glycerin, 5 oz soda, 12 oz of water and 7.5 oz 80% proof vodka. Superfat at 7%.
Fragrance is Rosemary. Nothing else.
I am using a crock pot at Hi temperature but it does not heat more than 160-170 F.
Thank you for your help.
 
Last edited:
I don't know anything about HP soaps so I'm really curious to see what the more experienced soapmakers here have to say. Compared to what I know about CP, a couple things stand out to me about your recipe: unusually high percents of castor and coconut oils, a lot of sugar, a lot of non-oil liquid, and the inclusions of stearic acid, glycerin, soda (baking soda?), and vodka. Maybe that's common for HP? Also, are you measuring by weight or volume? Is this a recipe you got from somewhere? What are your goals for the soap?
 
What are you trying to make, a transparent soap, or a liquid soap paste? I am also not sure what the soda is you mentioned above. This is not a regular hp soap, so I am guessing a transparent soap which will come out smelling different that normal cp or hp soap, but to me not a rancid smell
 
From the sugar and vodka, I think he is trying to make clear soap?

Rosemary fragrance - does this bottle say 100% rosemary essential oil. NOT 100% rosemary oil.

If it is a synthetic fragrance - where did you get it? Is it specifically CP safe?
 
Thank you all for your answers!
what I meant for soda is sodium hydroxide.
I was trying to make a big batch (14 to 15 - 4 oz soap bars)
And yes, I was trying to make transparent or translucent hp soap.
 
If you're new to soap making, one of the most foolhardy things to do is to make a big batch of soaps. If every batch was the same size as this one and they all smell rancid, you wasted a lot of time and resources as that is 45 bars of bad-smelling soap you're better of tossing.

Also, where did you get your recipe from and why would you want to make a clear soap without even having a deeper working knowledge of successfully making a 1lb batch of soap? That in many respects is asking for avoidable trouble.

Lastly, are you familiar with soap calculators? Anyone who has made a clear soap before may have to correct me but that recipe is awfully cleansing and extremely hard. I don't know if you would really enjoy that soap.
 
Thank you Arimara, you are right. I will try making a 1lb batch. I did use a soap calculator and it came out with a 45% conditioning, 59% bubbles, 52% hardness, 52% cleaning, 49% persistence, 57% drying and a 58% solubility factors. I learned my lesson.
Thanks again!
 
Thank you Arimara, you are right. I will try making a 1lb batch. I did use a soap calculator and it came out with a 45% conditioning, 59% bubbles, 52% hardness, 52% cleaning, 49% persistence, 57% drying and a 58% solubility factors. I learned my lesson.
Thanks again!

Overheating is probably the cause of the smell.
Try a 1 pound batch but keep the temp as low as possible.
 
When did you notice the rancid smell? During the cook? Or later?

How fresh were your oils to start with? Did you buy them brand new for this soap, or were they already in your kitchen and possibly old? I made the mistake when I first started soaping, of using oils sitting around my kitchen for an undetermined length of time. I thought it would be okay to use up old oils that I didn't really like cooking with. I had even done a search and found a site with instructions how to 'clean' rancid oils and take away the rancidity using a salt bath. Well I can attest to the fact that it does not work to remove all rancidity in case anyone is ever tempted to try this. The soap made with that 'cleansed' oil still developed DOS and (dreaded orange spots) and eventually turned the soap orange and the rancid smell in the soap was quite horrible as the DOS spread throughout the bars.

It was a learning experience, but I could have certainly used my time and resources more wisely if I had only known what a wasted effort that was. :)
 
Hi Earlene!
I noticed the smell during cooking and after. My oils were fresh. Just purchased them. I am going to try one more time but this time with a smaller amount of oils.
I am going to keep an eye on temperatures. That might be the problem.
Thanks for your prompt reply!!
 
If you're new to soap making, one of the most foolhardy things to do is to make a big batch of soaps. If every batch was the same size as this one and they all smell rancid, you wasted a lot of time and resources as that is 45 bars of bad-smelling soap you're better of tossing.

Also, where did you get your recipe from and why would you want to make a clear soap without even having a deeper working knowledge of successfully making a 1lb batch of soap? That in many respects is asking for avoidable trouble.

Lastly, are you familiar with soap calculators? Anyone who has made a clear soap before may have to correct me but that recipe is awfully cleansing and extremely hard. I don't know if you would really enjoy that soap.
I happen to make a very gentle lovely clear soap, but do not use alcohol and do add in some surfactants and use propylene glycol as part of the solvents.

Making clear soap is a different animal than making regular cp or hp soap. I really enjoy the process of making transparent soap but since it is not a great seller I do not make a lot of it. Mine is made with Avocado as one of the oils and it is lovely, but is not really a m&p, just transparent
 
It couldn't hurt to sniff your bottles, including the essential oil, just in case. I once bought a rancid oil. It happens ;)
 
I've tried making transparent soap with ethanol a few times, but the smell of the soap mixed with alcohol is something I just can't stand. If your ingredients smell fine on their own, I'm thinking it could be that combo. Do you smell it before adding the alcohol? Also, there's a lot of coconut in there. In solvent-heavy soaps, I tend to stick with 30%. My nose is sensetive to the smell of (I think) lauric acid. High percentages of coconut oil in soap (and small amounts in leave-on products) smell bad to me--very acrid.
 
First of all, good for you if you made 3 batches of transparent soap and your only problem is "it smells rancid"! LOL Well done! Pics please.

Transparent soap is one of the first soaps I made when I first started soapmaking back in 2004. This formula looks fine to me but I needed to reorganize your information in order to make sense of it. (See SoapCalc Sheet attached below.) I've not tried any of the latest approaches online today, so I would be very curious to know how you processed this soap? Link please, if it's not too much trouble.

I'm somewhat concerned that you used 80-proof vodka, i.e., 40% alcohol by volume. Normally recipes call for at least 80% alcohol by volume for successful transparency. I use 190 proof Everclear. Since your oils were fresh, and you soaped at 160-170, for the "rancid" smell I'm wondering if perhaps you used an inferior brand of fragrance oil? Rosemary has a unique scent that could very well smell "off" depending on whose fragrance oil you used.

SoapCalc.png

HTH :bunny:
 
Is it possible that you haven't made/used handmade soap before and is mistaking the soap smell for rancid smell? I know I thought my soaps smelled wierd when I just started making soap even though there wasn't anything wrong with them.
 
Is your added fragrance a proper, reliably sourced soap-safe essential or fragrance oil? I had one early batch smell really bad because I used what I thought was tea tree essential oil, but it was just "tea tree oil" which absolutely did not work.
 
Back
Top