DOS but Oil Doesn't Seem to be Rancid

[Arlo]

I'm pretty new to CP soapmaking and have made four batches so far. For batch #1 I used an organic EVOO (I know, sounds extreme, but it was all I had and wanted to get started). For batches #2,3,4 I've been using a an olive oil from Costco that is 15% extra virgin. The recipe is mostly OO with a small amount of coconut and castor. Batch #2 started getting DOS after a while. Of course at first I had no idea what it was (so went on to do more batches) but with research found out. Batch #3 has a little DOS, and batch #4 is too recent to tell, plus it has specks of orange rind that might hide DOS. (FWIW, batch #1 with the EVOO has no DOS at all.)

So here is my problem: I still have about 1-1/2 quarts of the Costco oil. The exp. date is Dec. 2020. It does not smell rancid although I was storing it in a garage where temps fluctuated. Probably not a smart thing to do. I've read the methods of washing the oil which I guess I can try. I'm just puzzled as to why the oil doesns't smell rancid, and if it's not rancid what could the DOS come from?

For batch #2, I cut off all the DOS which left me with bars of weird shapes so I grated them and made laundry detergent. I haven't used it yet, but it occurred to me now that if there is rancidity, maybe that wasn't such a good idea. I guess I'll find out after doing a few washes and seeing if it smells.

Thanks for any input.

 

[Relle]

Read post 12 on this thread re DOS. First paragraph
https://www.soapmakingforum.com/threads/bar-issues-after-4ish-months.76527/#post-789014

 

[shunt2011]

Also, just an FYI it may not make good laundry soap either. If it's got a superfat keep in mind that's extra oil in the washer. Most laundry soap is made with 100% Coconut oil and 0 SF. Lots of things can lead to DOS. Contamination is probably more common than we think. Where the soaps are stored and how can also play a large part. It's not always due to rancid oils. I use the OO from Costco that comes in 2-3 liter bottles and have never had an issue using it. I've had some DOS but due to other issues. (stored in the back of my van in a plastic container) not one of my brightest moments.

 

[Arlo]

I'm encouraged to think it might not be the oil although in a way it makes it harder to diagnose. I have been curing my soap on metal (stainless) racks. I saw the other link said metal racks can cause DOS, but I wonder if that includes stainless steel. I can certainly research that question elsewhere. In the interim, I put them on a towel. Otherwise, I store the soap in a well-ventilated closet, dry environment. I guess I'll keep looking into this! Thank you.

 

[shunt2011]

Even though they are stainless it may be your problem. Them sitting directly on the metal could be it. I would place some parchment or freezer paper. As long as the closet has good circulation it shouldn’t be an issue.

 

[DeeAnna]

Most metal racks are chrome or nickel plated steel. But even if the shelves really are stainless, you're still better off not putting your soap directly on any metal to cure. Some stainless isn't the best, so it may not be as perfectly inert as you think it should be.

I know we often use stainless equipment to make soap -- my stick blender in particular -- but blending the soap with a stainless stick blender for a few seconds is not at all the same as curing and storing the soap for weeks or months on a metal shelf.

There have been a fair number of questions about rancidity and DOS of late, so I published a new article about this topic on my website -- https://classicbells.com/soap/rancidity.asp Hope it's helpful to y'all....

edit: second paragraph slightly edited for clarity.

 

[Keaton]

Even though they are stainless it may be your problem. Them sitting directly on the metal could be it. I would place some parchment or freezer paper.

I hopped up from reading this post to go put my new batch (resting on a metal rack) onto a piece of parchment LOL thank you for the info!!

 

[amd]

I have been curing my soap on metal (stainless) racks. I saw the other link said metal racks can cause DOS, but I wonder if that includes stainless steel.

For a brief time I cured my soaps on a (new) stainless steel shoe rack. All of those soaps developed DOS, so I tossed the rack into the shoe closet where it belongs. I suspect your rack is not properly stainless steel (not a metal expert so I'm sure there's some terminology for this).

 

[Dawni]

There have been a fair number of questions about rancidity and DOS of late, so I published a new article about this topic on my website -- https://classicbells.com/soap/rancidity.asp Hope it's helpful to y'all....

Oooh new bookmark! Hehehe

 

[Mistrael]

Could it be the nickel? Most stainless has nickel, unless it's properly hypoallergenic for jewelry. (Something I discovered the hard way b/c of metal allergy.)

I just got started myself, and not wanting to spend too much money to start, I bought a large package of cross stitch plastic for this purpose. So far it's working nicely, and since I also cross stitch and have kids, I have other uses for the big package. (From Amazon, btw.)

 

[shunt2011]

Could it be the nickel? Most stainless has nickel, unless it's properly hypoallergenic for jewelry. (Something I discovered the hard way b/c of metal allergy.)

I just got started myself, and not wanting to spend too much money to start, I bought a large package of cross stitch plastic for this purpose. So far it's working nicely, and since I also cross stitch and have kids, I have other uses for the big package. (From Amazon, btw.)

That’s what I’ve lined all my metal shelving with for curing. Works great and easy to keep clean. Been using it fro 7 or so years now.

 

[Mistrael]

That’s what I’ve lined all my metal shelving with for curing. Works great and easy to keep clean. Been using it fro 7 or so years now.

Yay! I'm happy to hear that this is effective long term!

 

[Marilyn Norgart]

ive read before if you use a magnet on something that says SS and it sticks it isn't SS

 

[DeeAnna]

Some stainless steel (SS) alloys are magnetic and some are not. If the alloy is magnetic, the SS will often not be as strongly magnetic as regular iron or steel, but a magnet will definitely stick. Despite what you see on the 'net, you can't judge the quality of SS by whether it attracts a magnet or not.

 

[Mobjack Bay]

There have been a fair number of questions about rancidity and DOS of late, so I published a new article about this topic on my website -- https://classicbells.com/soap/rancidity.asp Hope it's helpful to y'all...

Spirulina... DOS...

 

[Marilyn Norgart]

what you see on the 'net

didn't see it on the net someone who works with stainless a lot told me that. oh well

 

[DeeAnna]

...someone who works with stainless a lot told me that....

That is a common misconception. I have worked around various SS equipment long enough in industry to know some SS alloys are magnetic and some are not. I could see if a person worked with only the non-magnetic SS alloys, they certainly could use a magnet test as a quick check that the metal they're working with meets their needs.

Regardless, the magnet test isn't definitive proof that a metal object is SS or not SS. But I'm not any kind of expert on SS alloys and their magnetic properties, so here are two quotes to explain --

"...the most common stainless steels are 'austenitic' - these have a higher chromium content and nickel is also added. It is the nickel which modifies the physical structure of the steel and makes it non-magnetic...." Source: https://www.physlink.com/education/askexperts/ae546.cfm

"...The two main types are austenitic and ferritic, each of which exhibits a different atomic arrangement. Due to this difference, ferritic stainless steels are generally magnetic while austenitic stainless steels usually are not. A ferritic stainless steel owes its magnetism to two factors: its high concentration of iron and its fundamental structure...." Source: https://www.scientificamerican.com/article/why-dont-magnets-work-on/

And even if a SS alloy starts out as non-magnetic, it can become slightly magnetized if its crystalline structure is altered through bending or other mechanical work --

"The most popular stainless steel is Type 304, which contains approximately 18 percent chromium and 8 percent nickel. [This is the 18-8 alloy often used for dinnerware] If the alloy is mechanically deformed, i.e. bent, at room temperature, it will partially transform to the ferritic phase and will be partly magnetic..." Source: https://www.scientificamerican.com/article/why-dont-magnets-work-on/

If you need more, google "stainless steel magnetic".

 

[Marilyn Norgart]

If you need more, google "stainless steel magnetic".

no need to I wasn't trying to offend you. I know you work with that stuff and I was just saying I heard if from someone else that did too. And I am wondering if he told me how to tell if it was 316 SS--anyway you made your point. I do believe I made a short comment that that is what I heard--never said I didn't believe you. it is kinda funny though that you told me not to believe everything on the net but then tell me to google--just saying

 

[DeeAnna]

I didn't take offense, Marilyn. I apologize for giving you that impression!

I know I tend to over-explain (as I realize I did here!) and often use a factual engineer/professor tone. I'm aware that doesn't always come across as friendly repartee, but it doesn't mean I'm offended or upset.

 

[Marilyn Norgart]

I'm aware that doesn't always come across as friendly repartee, but it doesn't mean I'm offended or upset.

thank you!! I have been sitting here kind of upset and trying to tell myself that things don't always come across how they are meant to on the internet. also trying to figure out if I offended. I look to quite a few of you guys on here for advice, I love all the aspects that I learn about on this site