using KOH for the first time

[SoapDaddy70]

Getting ready to use KOH for the first time and bought a 2lb bottle off Amazon of the Essential Depot brand. Does anyone know what purity their KOH is? I am looking at the MSDS sheet and saw this on page 4.

Component Percent [%] CAS Number
Potassium hydroxide 84.0 - 92.0 1310-58-3
Water 8.0 - 16.0 7732-18-5

Would it be safe to assume that I could enter 90% purity in Soap Making Friend or should I split the difference and enter in 88%? Entering the shave soap rabbit hole and feel like a newbie all over again. Thanks in advance for any help on this.

 

[AliOop]

I use that brand of KOH and put in 90%. Haven’t had any issues yet, but it is a bit nerve-wracking with my 0% SF liquid soaps. You will probably be adding a post-cook SF for shave soap, so there is a bit more margin for error. Good luck!

 

[DeeAnna]

You'll have to pick a reasonable number and see how that works for you. As you note, the middle of the range is 88%. You could plausibly use 88% ... or use 90% as AliOop does. Either one is a valid guess that I would be comfortable using.

If making liquid soap and the soap routinely separates after dilution, indicating the superfat is too high, then you might want to lower the estimated purity by a few percent. If the soap is routinely lye heavy, then raise the estimated purity. If you're getting decent results -- not lye heavy, no separation -- then you guessed good.