Wednesday, December 5, 2012

Lye crystals vs soda ash

When I first started making soap, one thing I was really unsure about was how to tell the difference between soda ash (which is not harmful, but may affect appearance of the soap) and lye crystals (which are definitely harmful and would indicate the soap is lye-heavy and needs to be properly disposed of).  From what I had read, they were both white and formed kind of crystal-like on the tops of soaps as they cured.  Each time my soaps cured for the first few months, I would approach the soap with a fair amount of trepidation, lick my finger, touch the white crystals, and touch my tongue and wait to see if I got a *ZAP* like a 9-volt battery.

Perhaps these pictures will help others identify what white stuff on soap is safe and cosmetic only vs what is very dangerous.  I was trying to use up some oils that I'd had for a half year or so before they started to spoil, and I had gotten some Moroccan Red Clay in the mail, as well as some silk.  I wanted to make something moisturizing and gently exfoliating for the dry Minnesota winter coming up, and I had the evening by myself, so it was a perfect time to get down in my "lab" and play around.

So, I'm still not 100% sure what went wrong, but I am worried that I mis-measured the lye.  My husband helped me set up a soapy lab downstairs so I don't have to drag everything up to the kitchen each time I want to soap.  However, the light in the basement makes the scale a little tricky to read, so I have a feeling I just misread my digital scale and had way too much lye in this soap.

Here's the soap I made with the lye crystals.  It has also leaked lye-heavy liquid while it was curing, but that seemed to have seeped back into the mold by the time I took this picture.  See how it looks kind of spotty and crystalized?  Some of the whiter areas are where they lye liquid dried.

Here's a photo of some sample soaps I cut of a peppermint EO soap that had some pretty significant soda ash.  See how it looks less like crystals and more of a uniform "ashy" kind of white substance?

Here's a photo of both together (pardon the mess of my soap factory (and the quality of my pictures - taken on my iPhone with the previously-mentioned terrible lighting).

Here are the swirls from my caustic soap.  I'm so bummed I have to trash this batch!  The swirls turned out so pretty :(
At least I know the soap has great bubbles!  Check this out when I was cleaning out the mold!
So, time to toss this batch and try again.  I have wanted to play around with the BB Column Mold since my struggles unmolding my cream shave soap (I ended up hacking off the end with a small axe...).  Maybe this will be the soap for my second go with the column mold?

Happy Repeal Day!  Hope everyone is enjoying a cocktail tonight to celebrate the end of Prohibition :)  I am enjoying a Guinness and watching Bootleggers on TV!



  1. Such a nice soap,Chrissy, it's a shame it will end up in the garbage! Thanks for sharing your experience!

  2. So sad... The soap had perfect swirls. Did you try to remake it?

    1. Thanks, Kirppu - I really liked how it turned out! I did decide to try again last night, using the column mold I have, so hopefully that one will turn out just as nice (but with no excess lye...)

  3. Thanks, Diva Soap! I know, I am still sad about it. At least it was made of oils I was trying to use up?

  4. Such a gorgeous soap! Did you know you don't have to throw it away if it is lye heavy? You can rebatch it into laundry soap as long as the superfat is 3% or below. I wouldn't want to see such a pretty soap be wasted.

    1. That's a great point, Anne-Marie - I haven't been adventurous enough to try rebatching a lye-heavy soap yet, but I am worried that the other measurements for oils might be off, too, since it was so difficult to see the scale measurements that night? It's my mystery soap, and it's certainly taught me to get better lighting in the basement!

  5. That's really helpful to see what lye crystals look like. I haven't had that happen yet, so it's good know what I would be looking for...thanks for sharing this!

  6. Thanks, Natalia! I ended up re-making this recipe with better lighting (so I could see the scale), and it turned into my favorite winter soap. I'm so pleased with how it turned out!


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