Vinegar and citric acid

nframe · Oct 25, 2019

Having read about the benefits of using vinegar in soap, I made a small batch yesterday (500g). I used 70g vinegar (5% acetic acid) and an extra 2.5g NaOH. I also used 10g citric acid and an extra 6.24g NaOH. So, in all I used 8.74g extra NaOH. It all went well but today I was expecting the soap to be very hard and it isn't. In fact, it is a lot softer than when I don't use vinegar. My question is: should vinegar and citric acid not be used together? Does the citric acid cancel the hardness that the vinegar is supposed to bring?

Incidentally, I did not colour the batter and it turned out to be a lovely very pale yellow...

penelopejane · Oct 25, 2019

Yes I found that too. In my notes I have don’t use vinegar and CA together. I don’t know why this happens. I also used the right amount of extra NaOH.

Neither vinegar nor CA will colour your soap.
I use CA at 1% in all my soap (I gave up on vinegar) you’ve used it at 2%.

nframe · Oct 26, 2019

Thank you for this. Did your soap ever harden? Was it usable in the end?

penelopejane · Oct 26, 2019

nframe said:
Thank you for this. Did your soap ever harden? Was it usable in the end?

No they didn't. Some I used with 5% KOH which I find makes my recipes soft as well so that would negate those recipes. With all of these the soaps appear to get hard enough to use but as soon as they gets wet they dissolve really quickly.

SoapSisters · Oct 27, 2019

This just happened to me too! I used apple cider vinegar as half my liquid (40% lye concentration) and 1% citric acid. Soap Making Friend calculated the extra lye for me. The soap is only a week old, but much softer than a previous soap I made without the combination of vinegar and citric acid. I also added honey to the batter and thought that maybe that's the reason it's softer, but hmmm . . . this has got me thinking.

penelopejane · Oct 28, 2019

SoapSisters said:
This just happened to me too! I used apple cider vinegar as half my liquid (40% lye concentration) and 1% citric acid. Soap Making Friend calculated the extra lye for me. The soap is only a week old, but much softer than a previous soap I made without the combination of vinegar and citric acid. I also added honey to the batter and thought that maybe that's the reason it's softer, but hmmm . . . this has got me thinking.

I use honey in a soap and it isn't soft.