Opinions needed on ~possibly~ rancid oil

[Megan]

So I've been dabbling in all sorts of products. A couple of months ago, I made a couple lotion variations. Now, I made two with rice bran oil which smelled fine at the time. Those two are now definitely rancid...and for sure the RBO is to blame as it was the only difference in those two. The lotions have that very distinct old crayon smell.

However: I went to smell my stock of RBO...and it smells fine. It just turned a year old in March, so I know it's pushing it. The lotions were made in January and I've used the oil in several soaps since.

Now after all the backstory, my question: if my stock smells fine still, should I use it in soap? Or am I just asking for trouble? What about all of that soap I made after the lotions? They all look fine so far, but man it would suck if they started going rancid like the lotion.

 

[Arimara]

RBO should be able to keep for a bit. What else did you use for your lotions? I'm wondering if it may have been another ingredient.

If it smells fine, it should be fine for soaping with.

 

[Megan]

I made four lotions in total two with olive oil which smell fine and two with rice bran oil which smell like crayons. All of the other ingredients are the same between all the batches

 

[DeeAnna]

When you make lotion, you're blending fat with water (and maybe even some air). This creates a perfect environment for rapid oxidation of fat. Fats in a lotion are more likely to go rancid than pure fat for this reason. Soap obviously has fat and water too, but it's not as likely to go rancid, probably because the fat in soap is no longer just fat; it's soap.

Oxidation can be especially fast if the lotion only contains fats with short shelf lives, in other words, fats with a lot of polyunsaturated fatty acids. Examples -- RBO, hemp, grapeseed, macadamia, rose hip, borage, argan, etc. Olive is high in monounsaturated fatty acids and is quite a bit more stable.

I always add rosemary oleoresin extract (ROE) to fats to lengthen the shelf life if they don't otherwise have an antioxidant added by the supplier. If the fat already contains an antioxidant such as BHA or BHT, I don't add ROE -- too much antioxidant can cause trouble.

I also usually include a fat with a long shelf life in the lotions I make. This is another good way to protect against oxidation and rancidity. Jojoba and meadowfoam are my favorites, but even coconut is very stable and works well.

If I make a fat with a really fragile fat like rosehip, I will package the lotion in several small containers, leave one container out for use and store the others in the refrigerator. I'll also store fragile fats in the fridge or even the freezer.

 

[Susie]

If you are going to sell or give that soap away, I would not trust that oil. You just don't know how long they will let it hang around. If you are going to use it yourself, be sure you are willing to waste the other ingredients. I use the "if in doubt, toss it out" method of dealing with questionable ingredients. I had to toss about 25 lbs of soap due to DOS (olive oil that was still in date, but close to expiration). Never again.

 

[Megan]

If you are going to sell or give that soap away, I would not trust that oil. You just don't know how long they will let it hang around. If you are going to use it yourself, be sure you are willing to waste the other ingredients. I use the "if in doubt, toss it out" method of dealing with questionable ingredients. I had to toss about 25 lbs of soap due to DOS (olive oil that was still in date, but close to expiration). Never again.

That is my fear. I am planning on using it for personal soap at the moment... But I'm worried about my recent soaps as well... They are so pretty! It would be a shame to lose them!