My DOS Challenge Experiments

7 weeks ago I decided to make 1 lb CP batches to test various oils for DOS. I also used EO blends new to me to see how I liked them in the final soap. All recipes were exactly the same except for the "test" oil which I used at 20%. I didn't add any color and soaped a bit cooler than I should have using palm oil so got lots of "palmy bumps" (as I think of them, lol). The 4 oils I tested were soybean, grapeseed, canola and sunflower. These oils smelled just fine OOB with no hint of rancidity and were within the expiration date on the bottles. The basic recipe was:

30% PO
25% CO
20% test oil
20% OO
5% Castor oil
1.5:1 water : lye ratio (40%)
4% SF
Each batch was scented with 1.0 oz (28gms) of various EO blends.

All have been curing in open air for the last 7 weeks and MOST are dandy except....the soybean. 2 bars have visible spots of DOS and have an off smell (the top soy bar has the DOS spot on the back so you can't see the "soy" stamp). The EO blend is lemon, bergamot, eucalyptus and lavender. The first month it smelled great. Now, not good at all. It's difficult to find the EO's under the bad oil smell. I just checked the soybean oil container and the expiration date is 5 months from now and smells fine OOB. I guess I'm moving that to my kitchen.:wink:

From here I'm going to put one bar of the grapeseed, canola and sunflower into a zip lock bag, keep one unwrapped and use the other 2 (one in a shower and one at a sink). I don't want to use the soybean because they really don't smell very nice but I want to continue to watch them so I'll keep 2 in open air and put 2 into zip lock bags.

Just wanted to share the results of my oil experiments!

I'm curious if you would willing to try one in a cloth bag, like muslin, or wrapping it in cloth, one in a zip lock and one in open air. There was an experiment done by someone comparing open to muslin and the muslin really won out. Was it just from having less exposure to light and air or something about cotton cloth? I would love to see if there is a difference between completely sealed (the zip lock) and partially closed off (the muslin/cloth) and open. I know I should just do it myself if I want to know, but I thought there would be no harm in asking.

Thank you for posting about this. I love being able to see other people's experiments!

newbie said:

I'm curious if you would willing to try one in a cloth bag, like muslin, or wrapping it in cloth, one in a zip lock and one in open air. There was an experiment done by someone comparing open to muslin and the muslin really won out. Was it just from having less exposure to light and air or something about cotton cloth? I would love to see if there is a difference between completely sealed (the zip lock) and partially closed off (the muslin/cloth) and open. I know I should just do it myself if I want to know, but I thought there would be no harm in asking.

Thank you for posting about this. I love being able to see other people's experiments!

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Ooohhhh! Good idea Newbie! I'll definitely do that. I don't have muslin specifically but I have some cheesecloth. Do you think that would work?

Interesting. None of my soy have ever developed DOS {thank goodness} so curious to what brand of SO you used?

Jstar said:

Interesting. None of my soy have ever developed DOS {thank goodness} so curious to what brand of SO you used?

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It's Wesson Oil I bought from the grocery store. The ingredient lists only soybean oil. This is my 1st DOS ever so I'm a bit fascinated by it!

This is the cheesecloth I've got. From what I can tell by the packaging it's just cotton. The thread count is about 10 so the weave is really loose and wide. If this is okay to substitute for muslin, I think I should probably double or quadruple the wrap. In this photo there's 2 layers of cloth over the bar. Any thoughts on it?

I have that cheesecloth (for straining my renders lol). It's very thin and "holey". I'd wrap it til it's opaque, probably a 3 to 4 wrap like you mentioned would suffice, I'd think. Not newbie, but just thought I'd throw out my opinion.

Thanks for posting this! Can't wait to see how things develop.

Not surprised about the soy, my early soap used quite a bit of crisco and they were the ones that got DOS. I've done single oil tests of peanut, avocado and canola. The canola is the only one that got DOS. I never have tried grapeseed.

I agree with LP about wrapping it in a few layers so it's opaque. I'm glad you are open to including that piece because the other experiment didn't have a sealed option. It will be VERY interesting to see what happens here. I know in the SF swap, people were getting completely different rates of DOS from bars that all came from the same batch so environment seems to count for a lot in the rate of DOS development, as well as ingredients. Thanks again for posting your experiment!

I was finally to get these soaps wrapped up.

As you can see in the first pic, I used an old nurse-y trick to mark the DOS spots. In the soap on the left, I used a fine point marker to outline the spot right on the soap bar since it's going into the cheesecloth. I marked over the spot, but on the cling wrap, in the bar on the right.

The 2nd pic is all four bars of soybean oil soap. The scent isn't pleasant so I'm not going to use any of them. I wrapped one with visible DOS and one without visible DOS in cling. I wrapped one with visible DOS in cheesecloth and left one without visible DOS open to air.

The 3rd pic is the rest of the test batches that have no signs of DOS. All smell like the EO blends I used so no rancidity at this point. I have 4 bars of each so 1 is in cling, 1 is in cheesecloth and 1 is open to air. The 4th bar is in a zip lock bag in my bathroom cabinet that I'll use in the shower.

I have all bars back on the drying tray in my curing area which is in a room with plenty of foot traffic and light (not direct sunlight). Does anyone think they should be moved to another area like a dark closet? Also, how long should I leave them alone before checking on them? It'll be easy to see what's going on with the cling wrapped and open air bars but I'll have to unwrap the cheesecloth to see how those are doing.

Hmmmm, I don't know about the timing piece. The other experiment showed the difference at a year, I believe, but I would be much more curious than that. Maybe check the cloth wrapped ones every month or 6 weeks? The world is your oyster on this one but weekly seems a bit much and a year seems too long. I would keep them where you usually keep your soap so the results apply to your situation and you can directly benefit.

newbie said:

Hmmmm, I don't know about the timing piece. The other experiment showed the difference at a year, I believe, but I would be much more curious than that. Maybe check the cloth wrapped ones every month or 6 weeks? The world is your oyster on this one but weekly seems a bit much and a year seems too long. I would keep them where you usually keep your soap so the results apply to your situation and you can directly benefit.

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I agree with the timing you suggested, newbie, so I'll take a peek every 4-6 weeks. If I wait a year to look at them, I'll probably forget they exist and come across them again in several years or never, lol. I'll also leave them out with my others for the same reason, so I don't forget they're there. Out of sight, out of mind is my moto!

Well, it's been almost a year since I set these aside, so out of sight was definitely out of mind! I had to rearrange my curing rack about 8 months ago so these got moved to the top. I rearranged again yesterday and poof! They magically reappeared. I obviously didn't check them every 2 months as I wanted but better late than never.

Pic #1: All the unwrapped soaps as they appear today. When I compared the look of the soaps after I cut to now, the soybean started out white, now mostly orange. Canola was light beige, now has an orange tint. Sunflower and grapeseed are mostly unchanged.

Pics #2 & 3: Soybean. The DOS that was there when I wrapped them are larger and more numerous. Very rancid smell to all bars. Interestingly enough is the bar wrapped with no visible DOS still has no visible spots and the bar open to air developed 1 spot that's about 3mm diameter. Generally they look ugly and smell worse. Soybean (Wesson Oil) is off my list of oils to use in soap.

Pics #4 & 5: Canola (not HO). This started out lovely. Nice lather and EO blend good. There isn't any obvious spots but the color has changed to light orange and the scent is definitely rancid. Since this test I've used HO canola and have had no DOS in about 6 months. I like the lather and the quality of the soap with HO canola so I'll continue to use it in certain recipes.

Pics #6 & 7: Sunflower (not HO). This soap is still really nice. There's no visible sign of DOS or a rancid smell. The EO blend has faded some but held best in the bar wrapped in cheesecloth (thanks for that suggestion, newbie!). Of the EO blend (ylang ylang, sandalwood FO, lavender, 10x orange & patch), the ylang ylang is most prominent. The lather is lovely. Definitely a keeper.

Pics #8 & 9: Grapeseed. I was pleasantly surprised to find no visible DOS or rancidity with this one. All bars look and smell fine, though a bit faint (as expected). This was equal parts ylang ylang and eucalyptus. Today I smell no eucalyptus, only light ylang. Go figure. As with the sunflower batch, the bar wrapped in cheese cloth held the scent best. I'm not crazy about the lather quality or quantity in this soap though, it's very sparse and takes a lot of work to build. I probably won't use it in soap again but I was happy with the outcome in general.

To sum it all up: I'm in love with sunflower oil, in strong like with HO canola, grapeseed is okay but not my best pal, and soybean is permanently off my dance card. Hopefully if I do this again with other oils I won't wait (or forget) for a year before performing my examination and posting results!

What EOs are used in these? I think they could have influenced the experiment. Some have been found to have antioxidant effect, so they could conceivably have protected the soap. Others (lemongrass in particular comes to mind) significantly discolor soap over time.

Thanks for updating Krista. I've been using HO sunflower lately and am glad to know it held up.

topofmurrayhill said:

What EOs are used in these? I think they could have influenced the experiment. Some have been found to have antioxidant effect, so they could conceivably have protected the soap. Others (lemongrass in particular comes to mind) significantly discolor soap over time.

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Soybean: Lemon, bergamot, eucalyptus, lavender
Canola: Cedarwood, lemongrass, spearmint
Sunflower: Ylang ylang, sandalwood FO, lavender, 10x orange, patch
Grapeseed: Eucalyptus, ylang ylang

I didn't know lemongrass discolors but I usually use yellow colorant so haven't noticed. What does it discolor to? 10x orange will slightly discolor for me but the sunflower blend had only 6 grams and there's no color change or hint of rancid odor.

KristaY said:

I didn't know lemongrass discolors but I usually use yellow colorant so haven't noticed. What does it discolor to? 10x orange will slightly discolor for me but the sunflower blend had only 6 grams and there's no color change or hint of rancid odor.

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I wasn't going to stick my neck out, but I was wondering if the Canola had lemongrass. It turns kind of an unattractive yellowish shade over 3 to 6 months. I saw it happen and then I read about it, so I'm pretty sure it's true. Unfortunately I eventually tossed my tester without photographing it. My friend JBot has the other one. If she happens to come by maybe she would take a pic.

topofmurrayhill said:

I wasn't going to stick my neck out, but I was wondering if the Canola had lemongrass. It turns kind of an unattractive yellowish shade over 3 to 6 months. I saw it happen and then I read about it, so I'm pretty sure it's true. Unfortunately I eventually tossed my tester without photographing it. My friend JBot has the other one. If she happens to come by maybe she would take a pic.

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I'd love to see a pic if JBot can manage it. The canola batch was yellow right from the start but I assumed it was the canola itself that caused it which is probably faulty reasoning. This blend is 41% cedarwood, 41% lemongrass & 18% spearmint so the lemongrass certainly could have done it. In the end it was a light orange color so could be both the LG and rancidity.

Last fall every batch of soap I made (a batch is 50 bars) ended up with DOS. I cried and cried so threw away all my oils I bought in the 35 pound containers and started fresh with new smaller containers from Columbus Oils in Chicago. Stopped using canola and using only Olive with Castor for 1/2 my oils. Haven't had DOS since and really didn't have the heart to try experimenting into which oil it was but it was every batch. You can imagine what I lost with not to mention time but I only use essential oils. Since that time I've been making 1/2 batches because I am still freaking out. I also wonder if those 35 pound containers they send me sat in some hot warehouse for some time waiting to be shipped. Love working with Columbus but another time when I order Castor Oil they went me Avocado Oil and I didn't look at the label so lost that batch before I realized what I was doing.