How hard can you get soap with KOH?

[Healinya]

I've always had this question in the back of my mind. There is a VERY successful soap business on one of the 'tourist' streets here. They say that one of the things that makes their soap 'better quality' is because they don't use sodium hydroxide, they use potassium hydroxide which, (they say) makes it much better. When I questioned and said that I thought you can't get hard bars from koh, they confidently said 'oh yes you can, you just use more of it'. So my question is.... huh? Is there ANY possible way to get a hard bar of soap from koh? I wasn't in the store as a customer when I heard this. I was talking to a friend who used to work there who swore that's how she did it...

 

[soapbuddy]

The only way you cen get harder soap that's made with potasium hydroxide is to salt it out the old fashioned way, like our grandmothers did.

 

[Healinya]

I suppose it's possible then. They are family owned, same location, since 1934.

 

[srenee]

Yep that old, they must know the trick.

 

[Healinya]

Well, now I'm really curious. They often have very sickly looking soap in the back on their workspace... slabs that are occasionally dripping... I'll have to look more into it. Thanks for the replies

 

[Lindy]

The only way you cen get harder soap that's made with potasium hydroxide is to salt it out the old fashioned way, like our grandmothers did.

Irena what is salting it out please? I've never heard that term - it is totally fascinating.

TIA

 

[soapbuddy]

The only way you cen get harder soap that's made with potasium hydroxide is to salt it out the old fashioned way, like our grandmothers did.

Irena what is salting it out please? I've never heard that term - it is totally fascinating.

TIA

I don't have the exact measurements or a recipe, by my grandmother cooked her soap in a big kettle that had extra water and she added a bunch of salt. The harder soap would end up on the surface, which was skimmed off and put in a wooden mold which was lined with some type of a absorbent cloth. The cloth absorbed any extra water & the soap became fairly hard. Then my grandmother would cut it with a large knife and let it cure.