Burnt oils

[Vidula]

Hi
I left the oils cooking overnight in the crock pot, heat on high! I forgot to turn it off. This morning the oils were burning and smoking. Can I still use it for making soap or will I have to throw it out? It was 1500 gm of oil and I’d hate to waste all of it. Anyone has tried making soap with burnt oils?

 

[shunt2011]

Nope, I would toss it. Not worth trying personally.

 

[Vidula]

Nope, I would toss it. Not worth trying personally.

Will do, thanks

 

[TheGecko]

Unfortunately, there is nothing you can do with burnt oils. It's not just the smell, burning said oils breaks them down.

 

[Arimara]

Perhaps too, you should consider a smaller batch of soap like 500g, if you're a newer soaper? 1500g is a lot.

 

[Saponificarian]

I would soap it. I just used up left over oils that we had from frying chips and roasting thanksgiving turkey. I HPed it and added fragrance oil. I just ensured the oil was well sieved with no tiny particles. It’s been a month and the soap is great. I did soap at negative Superfat. About -2.

 

[TheGecko]

I would soap it. I just used up left over oils that we had from frying chips and roasting thanksgiving turkey. I HPed it and added fragrance oil. I just ensured the oil was well sieved with no tiny particles. It’s been a month and the soap is great. I did soap at negative Superfat. About -2.

But was it burnt?

When I first started soaping I bought those 7lb bags of Palm and Coconut Oils from BrambleBerry. Since I was only making around one and two pounds batches of soap at a time, I was constantly reheating those bags in the microwave. I noticed it more with the Palm than the Coconut, that about three-quarters through the bag, that it was starting to get grainy. I knew from working in the fast food industry, and from having my own Fry Daddy and still preferring to fry my corn tortillas for tacos, that repeated reheating of oil damaged it. I didn't know of the specific chemicals reactions that took place, but I could see the physical changes in the oil...that it darkened and became thicker, and of course, I could taste the difference. Repeated heating of an oil changes its fatty acid profile. It causes it to undergo a series of chemical reactions like oxidation, hydrolysis and polymerization.

With the above said, there is lots of information on using used cooking oil for soap, but I haven't found any on using cooking oil that has been burnt. However, I did find an article at Natures Garden that was very emphatic that burnt oils cannot be used for soap making.

 

[Saponificarian]

But was it burnt?

When I first started soaping I bought those 7lb bags of Palm and Coconut Oils from BrambleBerry. Since I was only making around one and two pounds batches of soap at a time, I was constantly reheating those bags in the microwave. I noticed it more with the Palm than the Coconut, that about three-quarters through the bag, that it was starting to get grainy. I knew from working in the fast food industry, and from having my own Fry Daddy and still preferring to fry my corn tortillas for tacos, that repeated reheating of oil damaged it. I didn't know of the specific chemicals reactions that took place, but I could see the physical changes in the oil...that it darkened and became thicker, and of course, I could taste the difference. Repeated heating of an oil changes its fatty acid profile. It causes it to undergo a series of chemical reactions like oxidation, hydrolysis and polymerization.

With the above said, there is lots of information on using used cooking oil for soap, but I haven't found any on using cooking oil that has been burnt. However, I did find an article at Natures Garden that was very emphatic that burnt oils cannot be used for soap making.

If it was burnt black, I would still soap it. Simply for the knowledge and experience. Make a 500g batch and watch how it evolves over time.

My used oils was brown not black if that is what you are asking.

ETA: I don't like the absolutes that soapers peddle on forums... NaturesGarden said it doesn't absolutely make it so.. Did they soap it? How did it evolve over time? Did it DOS? We want to know! I am a rebel I guess.

 

[KimW]

I've been waiting and have been surprised, because there was a recent post from someone with very dark oils from a restaurant, and most of those replies encouraged the gal to soap with the oil to see what happened, unlike the replies here. How odd. @Saponificarian's reply has encouraged me (thank you, btw) to throw in my oar. I've never soaped with used oils from a restaurant, but I have soaped with burnt oils that I made all by myself - LOL. I mean smokin' hot burnt, as described by the OP. I rendered the burnt oils, as one would lard/tallow. The smell of burned oil was still present, though not as overpowering, after the second rendering. The oils made soap, even though the smell wasn't the greatest. I rebatched it and added some EOs. I can still smell the burned oil, but nobody else can, so it might be in my wee mind. Three things I noted: 1. The bars behaved as one would expect from the oil properties (long-lasting, high sudsing, etc), but 2. They never firmed up. That was 6+ months ago and they are still like soap dough/uncured soap. No perceptible excess moisture, just soft soap. What I find pretty cool really is they don't "melt away" when used, as I would expect from a soft bar of soap. 3.) The lather is reminiscent of OliveOil Soap - the lather is very slick, but not what I would describe as slimy - but there was no Olive Oil in the burnt oils -

SO - I say - Soap on, sister! Sounds like you may have already chunked the oil, but if it happens again, I encourage you to try soaping a small amount of the burnt oil.