Monday, March 3, 2014


I can't believe it's already been a year since I started the SINGLE OIL SOAP EXPERIMENT. My 30 lovely  bars (well, one not so lovely) have been patiently awaiting their day in the spotlight since I last critiqued them at 8 weeks into cure. Well, 9+ months later, they have not failed to deliver some interesting results!

A refresher on the experiment for those new to the blog:
I took 15 common soaping oils and made a soap with 170 grams of each single oil and a 41% lye solution. They were each cut in two, with one labeled "A" and one labeled "B". "A" soaps were stored in a cardboard box in a dry location. "B" soaps were stored in a cardboard box in a damp location. They were weighed, pH tested, and lather-tested upon unmolding, and then again at 8 weeks, and comparisons were noted. Phase 3 is their current states of being at one year old. I have not re-weighed them today, but did lather tests and inspected for rancidity and finger-test hardness (not specifically solubility). My method for lather testing* was to run the bar under warm water for 10 seconds, roll between my hands with light friction for 10 seconds, take the picture, rinse, and dry my hands between each soap. I do have a reverse-osmosis water softener so results in hard water may (and most likely will) differ. I'm also disclosing which oils I personally use, so that you can determine for yourself whether I'm objective enough for your discriminating taste. I feel I was pretty objective, because, let's face 40 years old, I can't remember which number stood for what oil at a year later until looking at my notes to write this post...

* Friction helps produce more bubbles and thicker lather with any soap - and these soaps are no exception. Check out Olive Oil's lather with more friction added. Makes a big difference! But for the purposes of this experiment, and to keep a "controlled" study (as controlled as I can be in my kitchen!), I wanted preliminary results that someone with no experience with handmade soap would get.

And so without further adieu...

Tallow - One Year Old

Tallow - Lather - One Year Old
Tallow is still a hard, white bar, very close to it's original size and shape with no signs of DOS ("Dreaded Orange Spots" - the soapmaker's term for rancidity). Not much lather to speak of, with very fine bubbles. Not very conditioning on the hands, but not drying. In my humble opinion, though I do not personally use Tallow (or any animal fats), it seems to be a good oil for bulk - a filler oil, if you will.

Rice Bran - One Year Old
Rice Bran - Lather - One Year Old

Rice Bran had thin light bubbles and felt good one the skin. The bars were hard and free of DOS. Would be a nice substitute for Olive Oil.

3. OLIVE (Castille)
Olive - One Year Old
Olive - Lather at Unmolding, 8 weeks, & One Year
If I used a lot of friction, this is the lather produced by One Year Old Castille
Castille Soap, or 100% Olive Oil Soap, has been lauded as the most gentle and hardest bar of soap you can make...and while that may be true, if you're looking for a nice bubbly bar - this isn't it. Though not as slimy of a lather as it was in its infancy, it still was more of a lotion-type feel, which is great if that's what you're going for. I didn't find it any more "moisturizing" or skin-softening than Rice Bran or Avocado. I wanted to finally be blown away by it's gentleness and get why everyone flips their wigs over Castille soap, but alas...
I use Olive Oil in 90% of my soaps however, and adore it blended with other oils that bring the other properties I'm looking for.
A very hard bar without a spot of DOS. Very much as it was, though harder and not as slimy.

Lard - One Year Old
Lard - DOS spot on bottom left corner of "A" soap (Dry location)
Lard - Lather - One Year Old
I was surprised to find a spot of DOS on the "A" Lard soap from the dry location. Otherwise, Lard didn't change much - a lotion type lather with no bubbles. Once again, I feel it may be good as a bulk or "filler" oil, like Tallow or Palm. Lard Soapers rave over it's conditioning properties, so if you're open to using an animal fat, it may be worth a shot when formulated with other oils.

Safflower - One Year Old - DOS on bottom left corner of "B"
Safflower - One Year Old - The beginnings of DOS on back of "A" & "B"
Safflower - Lather - One Year
Safflower is probably not one of the more common soaping oils, but there is use for it out there. At one year, it's beginning to show DOS on the backs of both "A" and "B" soaps. It is hard, but not super hard with very scant, almost imperceptible lather.

Soybean did not blow me away, though I'm suprised to say that there is no DOS at one year on either "A" or "B" soap. Not a super hard bar - I can't completely dent it, but there is a bit of "give" when pressing hard with my thumb. A little bit of lather, but in general, nothing to get excited about.

Avocado - One Year Old
Avocado - DOS spot on lower right back side of "B" soap
Avocado - Lather - One Year
I do personally use Avocado oil in a few of my soaps, mostly replacing part (or all) of the Olive Oil. However, on it's own? Well, it was starting a spot of DOS on the back of the "B" soap. About the same hardness as Soybean, and about the same type of lather. It does feel very nice on the skin though - soft and smooth with no drag. I definitely recommend it as a percentage of the formula, though maybe not as a stand alone oil.

Palm - One Year
Palm - Lather - One Year
I'm an Organic Sustainable Palm Oil user (Soaper's Choice), and this test has reinforced why I continue to use Palm Oil. Please don't read that as I don't care about environmental or animal issues in favor of making soap - I most certainly do care about both issues! I also realize that the Palm Oil issue is much bigger and more complex than to just stop using it. Everything is connected and every action creates a reaction. But that topic is for another post (that I will hopefully get to this summer).
Back on topic...the Palm soap is free of DOS, super hard, with a thick creamy lather. While I don't find it the most moisturizing of oils, my skin felt soft without the drag that it had after using the Palm soap in the beginning of this experiment. And while I compared Palm to Tallow and Lard as bulkers or fillers, I feel that Palm brings a bit more to the table than either of the other two.

The Corn oil soap surprised me...I expected a bit of DOS, but it was spotless and very much like it was at the beginning of the experiment. A pretty hard bar with a moderate lather of thin fluffy bubbles.It wasn't a stand out on any front, but I would consider it more than I would have before this experiment.

Sunflower - One Year Old...and obvious DOS on "A"
Sunflower - DOS on backs of "A" & "B"
Sunflower - Lather - One Year
And here's where things start to get ugly. And slimy. But mostly really ugly. DOS city, man. Not really stinky, but a bit of that "old oil" smell" - you would think it would smell worse by the way it looks. And strangely enough, the dry location "A" soap is worse (covered all over in orange-ness) than the wet location "B" soap (orange-ness on back only). It's a shame too, because the lather definitely improved since the beginning of the experiment - it actually had nice foamy bubbles!. It is soft, tacky, and starting to get a bit slimy. I would highly suggest checking out the High Oleic Sunflower Oil, as it supposedly has a longer shelf life, though I can not attest to that myself.

Grapeseed - One Year Old
Grapeseed - Progression of DOS
Grapeseed - Lather - One Year
And things get even uglier. And slimier. And smellier. And just gross. But no surprises here, really. We could see that Grapeseed was a mess from the beginning. It took forever to unmold because it was so soft. At eight weeks, it was already a soft, yellowy mess and smelled rancid. At one year, things have just progressed to the point of no return. There was actually a bit of wet, orange slime under this soap in the box. And the lather was actually orange! Ugh.
Funny thing: the other day I was reading an article from a business that shall remain nameless, stating that the main oil used in many of their products (salves, mainly) was Grapeseed, because of it's "long shelf life".
Way before this experiment, years ago, I had hands-on experience with Grapeseed Oil going rancid pretty darn quickly - less than 3 months in a product made for myself. Thank goodness I didn't sell it...that would have killed my chances of a soap empire. And this is why I do not use Grapeseed Oil in any of my products. Even with an anti-oxidant, you would still need a good preservative to make this last long-term. For a personal use product at home that will be used within a week or so, it may be fine.

I HAVE AN OBSERVATION: The Sunflower soap was next to the Grapeseed soap (in numerical order) in the box. At the 8 week mark, I separated them to opposite corners to see whether the DOS could spread from one soap to another. Now, I'm no scientist, per se. and this wasn't a sterile lab environment with controls (other than those mentioned above)...but I think it's possible that DOS can spread from one soap to another if they touch.

Another surprise here with the nice clean white bar - no DOS, pretty hard bar with decent light lather. Nothing to write home about, but a possible cheap alternative for experimenters out there.

Coconut - One Year with a small DOS on "B" soap
Coconut - Lather - One Year
Coconut always delivers on lather - that's no surprise. The dot of DOS on the side of the "B" bar is. I've never, ever had DOS on a soap made with Coconut Oil. Which brings me back to the question made in the observation above: Can one DOS infected soap contaminate another otherwise DOS-free soap? Hmm...I think I need to do another experiment...
Super hard white bar, thick bubbly lather...and I don't find it as drying as some other people do (even though my skin is dry by nature). It's still my Number One Oil, despite that random DOS dot. I think it's a fluke. In general, Coconut Oil, when stored properly, can last up to 2 years or more.

Peanut - One Year Old with small DOS on front lower right of "B"
Peanut - One Year Old - possible DOS on  back of "A"
Peanut - Lather - One Year
Peanut was a good bubbler right out of the gate. A nice hard bar with good lather, but it did get a spot of DOS on the front of "B", and what I think will eventually be DOS on the back of "A" (I don't think it's just discoloration). A good cheap-ish alternative for the experimenters.


Castor - One Year Old
Castor - Lather - One Year Old

Castor is the one oil I use in all of my soaps, usually between 5 - 8%. I find it adds nice moisturizing properties. Castor is always recommended to add bubbly lather (by me, too), even though you wouldn't think so from this picture. It's not a stand alone oil, though washing my hands with this one last left them soft and supple - no waxy drag that I noticed at the beginning of the experiment. Super hard bar, no DOS.

I wanted to add a few pictures for reference:
This is a soap I was gifted by another soapmaker and it is 2 years old.
Their recipe consisted of Lard, Crisco, Coconut, and Olive Oils (and I believe was scented with Cinnamon essential oil). The discoloration on the corner was there when I opened it, so I doubt it's DOS and may just be discolored from oxidation of the essential oil (my guess):
Fellow Soaper's 2 Year Old Soap

Fellow Soaper's 2 Year Old Soap
Fellow Soaper's Lather after 2 years
This is a piece of soap from the same soaper, discolored more from DOS (the same batch as the previous photos). It is very dry and hard, with a pretty strong rancid odor: Stored in a perforated ziploc bag in the linen closet in the bathroom.
Fellow Soaper's Non-DOS soap, and DOS infected soap from same batch - 2 years old

And here is a 1+ year old bar from a batch I made for my older son called Black Winter Sky. It's formula was Olive, Coconut, Palm, and Castor, scented with Clove, Patchouli, and Cedarwood essential oils, and colored with Woad (it was more blue, but faded to grey) and swirled (ITP) with Activated Charcoal. No DOS and was stored unwrapped in the linen closet in the bathroom.
The same lather test was done on both my soap and the fellow soaper's that I used in this experiment.
Black Winter Sky

So did you learn anything new from this experiment?
Did it get your gears spinning on a new oil to use?
Did it reinforce what you already use?
I can't wait to hear your deductions, observations, and opinions!


  1. This was a very interesting experiment. It reinforces my desire to try making some soap with castor.

    1. I really notice a difference in the lather and conditioning of my soaps when I use Castor! I usually use 5 - 8% in my formula. I have gone as high as 10% - though at 10% I did notice the bars could get a bit tacky and I didn't notice any difference in feel of the have decided that 5 - 8% in the "sweet spot" ;)

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  3. I'm impressed - keep meaning to do something like this myself. The sunflower oil is so interesting - I think it depends so much on the age of the oil that you start with and maybe the vit E level and prepurchase storage conditions. Plus I think higher SAPs with sunflower oils are better - check out the codex alimentarius - gives a range of SAPs - maybe those long chain polyunsats are just really hard to saponify and other factors such as the properties of the emulsion come into play - maybe a looser emulsion (more water) - is better? More experiments....

  4. I too am impressed with everything you've done! So plain, yet so elegant, so genuine, & strait forward...U GO GIRLY-GIRL!!!

  5. I'm looking into locally sustainable ingredients for a market. Thank you, I was wondering how corn oil would soap, I have never tried it. I am going to look into soybean and canola too. Now the tough part, finding local sources for these oils. Very interesting experiment.

  6. I had very interesting results with organic sunflower oil too. Dreaded orange spots city that's FOR SURE. Used in two batches- one very lye heavy and one 3% superfat. Both had DOS. Will never use it again

  7. I am so glad to have found your experience posted when I Googled 'what can I do with my single oil soaps?' I was actually thinking I might want to rebatch them together to make a better soap at some time in the future. But now having seen your posts, I may just hold onto the them for a year or so to see how they turn out.

    I just did this experiment myself, the single oil soaps. But I decided not to try it with Grapeseed Oil because I know it has such a short shelf life. I do use Grapeseed Oil in a bug repellant concoction that I use and have added that concoction to soap at trace. My son loves it in his soap.

    The soaps I tested included many of the ones you listed, except I don't use Lard at all, so did not bother with it. I also don't have any Safflower, Corn, Peanut nor any Soybean Oil, so didn't try them either. I did use Sesame Oil, Cocoa Butter, and 3 different kinds of Olive Oil, just for fun. And I did one with the 'new' Crisco, only because I thought it might be interesting since I had some on hand, even though I rarely use it for anything, even cooking. I also made one bar with Flax Oil, but have determined it was a failure from the start and probably won't be able to evaluate it effectively because I managed to over cook the soap when it came to trace too fast and I didn't remove it from the heat soon enough.

    My experiment began a few days ago, so I have really only noticed the hardness/softness and some color changes so far.
    I love the fragrance of the cocoa bar and of the sesame bar, but then I love those anyway. I adore the hardness of the cocoa bar and of the castor bar. I think there is something seriously wrong with the hardness value attributed to Castor Oil in Soapcalc. It's listed as a "0" and that's obviously wrong.

    Anyway I am really glad that I decided to do this experiment, too. I had read about doing it in the past, but it wasn't until I was trying to decide what my next soaping project would be and I read in a soaping book I borrowed from the library the suggestion to do this. Since we are taking vacation very soon, I thought this would be a nice quick fill-in-the time until we depart project.

    The only surprise I had from my experience and yours was the Olive Oil. You said your bar was hard from the first day. Mine (all 3, in fact - EVO, light and Pomace) all remained surprisingly softer than I expected from the start. The EVO is the softest of the three; the Light Olive Oil is actually cracking. The pomace Olive Oil bar is almost as white as the Coconut Oil bar, though, but it's still early in the cure and that may change.

    I was very disappointed in Canola Oil and Sunflower Oil. Makes me wish I hadn't bothered buying them at all. I never use them for cooking, so I'll have to use them to make soap, but at least I see from your notes that the Canola oil bar stood up fairly well on its own so I won't have any qualms including it in soaps. The sunflower oil though, does not seem a wise choice at all from your results. I will have to consider this carefully.

  8. Reinforced:

    1. Coconut is the true god of soaping oils.
    2. Olive oil is the false god, but I am not the only one who did blasphemy :p


    Must pick up some corn and peanut oils to see what happens.