> When added to cp soap the citric acid in the juice reacts with lye to
> form a kind chelating agent which ties up the metal ions in hard
> water. This boosts the lather and is said to keep down the formation
> of "ring around the tub."
Lemon juice, or citric acid, reacts with lye to make the tri-sodium salt of citric acid, which behaves as a chelator (attracts and ties up hard water minerals like calcium).
So adding either to your soap makes it more superfatted, and better behaved in hard water.
If you're using pure citric acid, you can calculate the precise amount of NaOH it will use, so you still have a good idea of the superfatting level... but acid levels in fresh juice vary, so the superfat is more of a guessing thing.
One of the best natural additives for handcrafted soap for performing better in hard water is sodium citrate. Sodium citrate is natural and it acts as a chelating agent for binding the metal ions in hard water, thus, allow for better lathering soaps and a reduction of soap scum in the tub.
Use from 0.1 to 0.5% citric acid as a chelating agent. Use the least amount of citric acid needed to combat your hard water problems.
Start at the 0.1 to 0.2% levels and work up from there. High amounts can also interfere with suds formation.
And add 0.571 oz of lye extra per 1 oz of citric acid.
Citric acid dissolves fairly easily, I set aside a little of the water and dissolve it in that, then add it just after the lye water to the oils.
Since some people do add the lye directly to lemon juice (carefully!!), you could probably also dissolve the citric in your full water before adding the lye to it. I just prefer to add to the full batch rather then directly to the lye.
Mary Anne
(Filed 2/24/2003)
>Why would >anyone want to add citric acid to a normal handcrafted soap???
> It seems to me that "acid" isn't probably the best thing to add to alkali when
>trying to have the alkali react with the oils and saponify.
>Why would somebody add acid which will counter the akali's function and inhibit
>a portion that should be there reacting with the oils in the recipe?
Because of the end product that citric acid + NaOH creates.
Oils + NaOH makes the sodium salt of the fatty acids (soap) PLUS citric acid + NaOH makes the tri-sodium salt of citric acid. This is a different compound, no longer an acid, but the trisodium salt of citric acid, a chelator, so when you use soap containing this compound in hard water, it literally helps tie up the hard water minerals which cause soap scum. In other words, soap containing this citric acid compound gives you better lather and less soap scum in hard water.
You get the same effect if you add lemon juice to soap, its citric acid makes the salt, and gives the same chelating effect.... except that with lemon juice you don't know how much you're adding, so it is harder to compensate for the lye used up by the juice. When adding pure citric, by weight, you can compensate exactly for the citric used, and know what your final superfatting level is.
Some people with hard water improve their soaps sudsing abilities by adding borax,.... citric does a better job, much less is required, (0.1-0.5% the lower end preferred) and its not on the health canada hotlist for controlled substances in cosmetics, as borax is.
Julie
The side effect of adding the citric acid is beneficial as far as it is able to get the PH down and soaps will not be as harsh.
Commercial baby soap has the PH of the eyeball, extremely mild, achieved thru Citric Acid and other things. This is why Natural Soap will burn far more than soap bought at stores. The other fact is that citric acid does cut down on the Scum that forms.
As for Lactic Acid I have my formula down where the Soap looks and feels like Milled soap and gives lots of moisture and Bubbles. Yet I am not so convinced of the product. I have had time when gelling the soap that it will get too hot (suspect the Sugar Part of Sodium Laurate) and it gets Brittle and smells funny almost burned. Again I think Sugar. That is the reason I asked if anyone is using SL. I myself would like to just experience Tallow soap and see if I can not get the same feel without the Volatility that SL has presented.
