Deanna, I have a question...

I have an Andalusian recipe for castile soap that is lye heavy, but makes the BEST castile soap and does not get gooey. The bar is wonderful, long lasting, and hard. I know it's the amount of lye responsible because I have made plenty of castile soap since and even with the long cure times (couple years) they get gooey. It isn't a recipe I sell for obvious reasons, but a few months ago I read a Soap Queen post featuring Kevin Dunn as the speaker. In the post he talked about how lye heavy soap will eventually become milder because (if I remember right) the oxygen will eventually eat up the extra lye. As I speak I have an experimental batch of my lye heavy castile curing in my soap work area which I will test the ph on eventually. My other batch of this was never stingy or anything. I had made it as a new soaper before I really was educated in lye heavy soaps. Anyway, it's been a few years since this batch, but I still remember how good it was....perhaps you have a few thoughts on this or can confirm Kevin Dunn's statements?
Cheers!
Anna Marie

wow very interesting about how lye heavy soap will become milder with time.

AnnaMarie, how much more lye did you add to your castile if i may ask?

Get ready to croak soapers...
1 quart (yes, quart) of olive oil
1 quart water
3/4 cup water (to dilute lye)
6oz lye

Yep! Yep! Yep! On all of it. Mix the quart of water and olive oil. Mix the lye in 3/4 cup water. Combine it all (no heating) and it will trace in approx. 20 min. Makes the best castile!
Ill brace myself for the lectures

No lectures here. I am VERY curious to hear more about this.

That reminds me of old fashion lye soap recipes. Water added to oils and heavy lye. Can't wait to see what your results are.

wowza... that turns out to be what.. at least -30%SF??? zomg!

on a slightly different note, the recipes on making mp base by kayla fioravanti also have a slight more lye than what's needed to have a 0% SF. the soap turned out fine. no burn, no itch, no nothing.

It turns out so nice! It's even fun to cut. It's pure white initially and slices like cheese. Ooo la la!

Best of all, no gooey ness! At all!

I suppose if you have to wait 3 months for a "normal" Castile anyway, then you could also wait for the mildness to come

seven said:

wowza... that turns out to be what.. at least -30%SF??? zomg!

on a slightly different note, the recipes on making mp base by kayla fioravanti also have a slight more lye than what's needed to have a 0% SF. the soap turned out fine. no burn, no itch, no nothing.

Click to expand...

more like -40. Not to sure I will even go there...and I am not one to superfat high if at all

cmzaha said:

more like -40. Not to sure I will even go there...and I am not one to superfat high if at all

Click to expand...

i know, i was like my jaw dropped when i plugged in the numbers on the calc. initially i thought it was only a slight excess, like when i made my mp base, but wowza -40 *gulp*

that's why i am very very curious about this. let's wait for DeeAnna to explain this from science pov.

but then AnnaMarie had used this soap w/o a problem.. hmmm...

There's a blog post about this on Soap Queen as well, but I'd like to hear what scientist Deanna has to say.

The tracing of this recipe is also interesting. It doesn't trace like normal with a gradual thickening. This one becomes a vanilla pudding when it traces- right away. You have to be careful because it seems like it might have traced before this, but it hasn't (made that mistake in one experiment). The soap mixture starts to rice heavily and then all of a sudden you have this thick, rich looking soap batter. Really cool!

how interesting!!! can't wait to hear results!

The thing about a lye-heavy soap "getting milder with enough time" is true. Kevin Dunn did some nice work on this subject; he summarizes his findings in his Scientific Soapmaking book for those with an interest in the nitty-gritty of soap chemistry.

Free sodium hydroxide (NaOH) in the soap will slowly react with carbon dioxide (CO2) from the air to form a milder salt. This salt is sodium carbonate, Na2CO3. It is the same chemical as the white ash that sometimes forms on the top of CP soaps. Sodium carbonate is also the same stuff as the washing soda that is often added to homemade laundry detergent. Although sodium carbonate is basic -- it has a pH above 7 -- it is a much milder chemical than sodium hydroxide. A soap in which free sodium hydroxide has been converted to sodium carbonate will be much gentler to the skin.

Because a bar of soap is a big chunk of stuff, it will take time to convert the excess lye within the soap. If you want to encourage this process, I'd recommend storing the soap so it is exposed to the open air. It's my guess that packaging soap in plastic, for example, might not be the best idea. On the other hand, you don't need to go to the other extreme and run a fan either. Just store the soap on a shelf or in a loosely covered box or whatever and have patience.

Here's the chemistry. First step is for the CO2 to combine with water (from the soap itself or water vapor in the air) to make a weak acid:

CO2 + H2O -> H2CO3 (carbonic acid)

Next, the excess sodium hydroxide (a base) in the soap reacts with the carbonic acid to make sodium carbonate and water:

2NaOH + H2CO3 -> 2H2O + Na2CO3

Yowza! My personal soap calc is coming up with a -43% lye "discount" with AnnaMarie's recipe. The old soap makers would have "boiled and salted" this soap to remove the excess lye, but AnnaMarie's experience clearly shows this soap can be fine as a CP soap if the maker has the patience to let the CO2 do its magic.

edit: I want to add that the old industrial soap makers knew that lye-heavy soap, which was pretty common back then, did become milder with time. But time is money, so they generally didn't cure soap long. They often deliberately sold lye-heavy soap (but NOT this lye heavy!) for laundry and general household use. end edit.

I don't think this recipe would be something I'd unleash on a beginner or someone who doesn't have sufficient patience. I also don't think I'd use this "give it time" approach for a soap that was poorly made -- for example, one that had layers of lye-heavy liquid and oil-heavy soap.

AnnaMarie -- Would you share the link to the SoapQueen post about the recipe? Pretty please?

I found the blog post on Soap Queen that I think AnnaMarie is talking about at http://www.soapqueen.com/bath-and-b...ference-guest-post-kevin-dunn-aka-dr-mcsoapy/.

Here's the part that talks about Dunn's research on lye heavy soap (BTW... love how they refer to him as "Dr. McSoapy"!):

"Dr. McSoapy told us about some of his research.*One very interesting finding he shared concerns lye heavy soap.*You may have read/heard that cold process soap gets milder over time.*To test this idea, *Dr. McSoapy and his team did an experiment on a lye heavy soap and showed us the results.A soap started out lye heavy (can you say ouch?) when it was poured. *I don’t remember the exact pH, but it had too much lye in it.*After 24 hours, the soap was still lye heavy.*However, after 11 weeks, the soap had a pH level very close to normal for soap.*The pH was at a safe level.*He explained that this happens because the CO2 reacts with the leftover lye to eat it up.*Well, those may not have been his exact words, but that’s what my brain heard.Anyway, it was very interesting to me that in a relatively short amount of time, a*lye heavy soap would become a safe soap.*The conditions in which the soap cured may have an effect on how quickly the soap becomes safe.If you end up with a lye heavy soap, be sure to check the pH if you plan to use it.*If you make soap from scratch, you know the drill.*Every soap may not reach a safe level within 11 weeks as the experimental soap did."

Sounds like I'm on the same wavelength as Dunn. Good!

Thank you Deanna for chiming in and reaffirming Kevin Dunn's statements. Queen Bee Soap has given you the link to the blog post featuring Kevin Dunn, and now I'm going to share the link for the actual recipe in question:
http://spanishjourneys.com/oliveme/2009/06/08/make-your-own-pure-castille-soap/
I discovered this recipe several years back when I was newer to soap making, but after I made it I became educated in lye heavy, super fat, etc. and I moved on past castile. However, I never forgot THAT soap. Well, I came back to it and decided to experiment using varied water and oil levels, but always with the appropriate lye amount- a big fat nothing. I REALLY hate gooey castile and even my 3 or 4 year old castile still got gooey (yes, I kept it out of water and on a draining dish, etc). It never made sense to me how great this soap was (and might I mention that I added peppermint eo to it which only added to its awesomeness), and yet the ever clear warning of lye heavy soaps. Sigh.... Then recently I read this blog post and the light went on. I made 2 batches which have been sitting in all their glory in my soap area in the shop. They formed lots of lye crystals within a couple of days, but now a month later many of them are gone. I plan to give these a good long cure (like a year) and then test the ph.
Maybe one or more of you will try it out?
Cheers!
Anna Marie

I found the same recipe at these sites:
http://www.ehow.co.uk/how_6942346_make-pure-castile-soap.html with attribution to spanishjourneys.com
http://peapodriot.blogspot.com/2010/10/basil-pure-olive-oil-castile-soap.html without any attribution

I'm taken aback that the spanishjourneys.com recipe and the ehow.com recipe (clearly adapted from the spanishjourneys version) say to use this soap after 2 weeks of cure. I wonder if either of these authors actually tried this recipe per instructions?

I also wonder how many people used either of these recipes for their first ... and very likely their last ... soaping experience? Like, really, think about it -- how many of us were totally able to wait TWO WHOLE WEEKS before trying out our VERY FIRST SOAP?

Okay, so now that I've gotten that off my chest ... I'm intrigued. But I also find myself wondering if this huge 40% or so lye-excess is necessary? I gather from your trials that a positive lye discount (superfat) or a zero lye discount results in gooey castile. But what about -5% or -20% or ??? What do you think, AnnaMarie?

I'm also curious, DeeAnna!

And the science behind the long cure for how the lye-heavy soap gets milder made me think... What would happen if you skipped the huge lye excess and replaced some or all of it with washing soda instead?? Would it harden up the same way, or would you get a sloppy mess the way you would adding baking soda?

...Now I really want to find some washing soda so I could try it out.

DeeAnna, Haha! Even then I knew better then to use soap that soon! I'm a patient person so I waited- no burns and stuff like that. And yes, I now look at this recipe as the height of soaping irresponsibility. I may have tried using less lye in previous experiments, but I can't remember. I primarily focused on different water percentages. I can't explain it, but this recipe just works.

I think I'll go take a picture of it and post it for you. Hang on...