Hello. I bought lye recently from the lye guy and it says the KOH is 84.5-90.5%. I want to make liquid soap and want to make sure I use the proper calculator. With this range would you suggest I click 90%? Or type in the lower percentage at 85%? Thank you for any suggestions as my brain is toast after reading these threads for weeks! Lol Kim
Lye question
- Thread starter zzzma
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If you choose the higher percentage, it would be the safest option of the two - it would reduce the amount that you use compared to the 85% setting. If you use the 85% setting and you have closer to 90%, you'll use more actual lye than you think.
^ Craig is exactly right. Better to have a tad more superfat than you typed into the lye calculator than lye heavy soap. If you stick with 0-3% superfat, you should still get clear soap. If not, we can fix it with a tiny bit of KOH mixed with water.
From The Lye Guy? At http://www.thelyeguy.com/store.php?crn=210 ? I'm a long-time customer of his, and I definitely don't recall his KOH purity has ever been listed as being that low. Here's what I just saw on his website: Potassium Hydroxide - 96% to 100%
It was on the MSD sheet that was in the box? I also want to say that I made a 1lb batch of the liquid soap IL posted the tutorial and it did exactly as described! I have 4 jars that we're diluting now with different percentages to find the sweet spot. Thanks again!
Hmmm. I'm really mystified now! Not that this is anything new! 
I hope the dilution goes well -- pics are always nice!
I hope the dilution goes well -- pics are always nice!
The MSDS and what's on his website are definitely not agreeing. A year or so ago, I asked him about his KOH lye purity, and he confirmed that the purity is 96% minimum. Maybe something has changed? I'm not sure what's going on, but Jim (the Lye Guy) is the only one who can figure this out.
Is that the Certificate of analysis or the MSDS? Because an MSDS will not say the actual percentage of a specific lot. Usually the certificate of analysis will give you that.
A lot of times, the CAS number for a chemical, encompasses a range of concentrations and that is how the product is sold. Then, the true percentage is given on the CoA. I remember we got in some hydroflouric acid into our lab once and I freaked out because it said "40% hydroflouric acid" on the MSDS. I was told it was supposed to be <10%. It was actually only 4.91% as per the CoA. This was due to the fact that the CAS number corresponds to a range of percentages but appears as "40%" on the MSDS.
I don't know if that's what's happening here, but it might be!
A lot of times, the CAS number for a chemical, encompasses a range of concentrations and that is how the product is sold. Then, the true percentage is given on the CoA. I remember we got in some hydroflouric acid into our lab once and I freaked out because it said "40% hydroflouric acid" on the MSDS. I was told it was supposed to be <10%. It was actually only 4.91% as per the CoA. This was due to the fact that the CAS number corresponds to a range of percentages but appears as "40%" on the MSDS.
I don't know if that's what's happening here, but it might be!
Point taken, Galaxy -- I really appreciate your sharp eyes! The document in the pic has a section headed "first aid measures" so that's got to be an MSDS, not a CoA.
Yup! Those are two small parts of the MSDS for the product in general. NOT to be confused with a Certificate of Analysis.
I used to have to have those for things like furniture polish. There's a head ache I don't miss.
I used to have to have those for things like furniture polish. There's a head ache I don't miss.
I guess because it was included with the lye it was for that batch sold? I bought both types of lye so there were both sheets included. I zap tested my soap base (using the 90% button) and all was good. So, should I call lye guy and ask, or use what's posted on website?
I would call Jim and ask. Then you know.
Maybe Jim doesn't know. Even experts can operate under some misconceptions. Maybe the product is 96-100% pure not counting moisture. I only say this because it seems way more plausible that it's 90% KOH and 10% water. I imagine truly anhydrous KOH is uncommon and expensive, and probably not uniquely sold by The Lye Guy while all our other suppliers carry some lower grade. I might be mistaken though.
