Citric Acid Use

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Sep 19, 2011
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Southern California
I always add in the extra NaOH because I do not want to add in the extra superfat that would happen if I do not add in the extra NaOH. Realistically my superfat is not going to be 2% since NaOH is not 100% pure. As mentioned I no longer use CA I find my EDTA + Sodium Gluconate works better.
Aug 3, 2010
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Central PA
Your posts (14 and 19) have been rather cryptic, so I'm not entirely sure if I'm answering the real question you're asking. I'd feel more comfortable if you'd provide a little more of your reasoning behind these brief questions.

I apologize. I have some strange tangential thinking going on with the soap that I made recently and understanding the chemistry of CA and soap making.

when I looked back at my written notes, I actually did calculate the right amount of CA and NaOH for those batches. But it was in my thinking I made the error of not enough NaOH that I thought about how that would affect my batches other than SF and what if I had too much CA instead.

my questions were more to satisfy a rhetoric for myself and to better understand some of the chemistry. I am just thinking about the possible outcomes for the soap and what might to expect. I know what lye heavy is like but what iS CA heavy (this is just me thinking and asking the vague questions) what’s the crystal formation that was being described by you and cmzaha at the 2.9% look like...I’m just ruminating.

I checked on my soap and it is rock hard; harder than any other soap I’ve had yet this early in the cure. I’m very excited to see how it performs in my hard water. Thanks for being patient with me!


Well-Known Member
Feb 20, 2013
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Thank you -- this helps.

Sometimes people ask brief questions that seem reasonable and straightforward, but then we get into a weird back-and-forth where it becomes obvious the question-asker isn't getting the information they want and everyone gets frustrated. Oftentimes this happens because the questions they're asking are not really on target with what they really want to know. So getting more background helps.

So I got to wondering if you were just wondering and were curious in general (yes!) ... or if you were wondering about something in particular but using words that were making me think you were asking about something else (no).

Good to be on the same page!
Feb 20, 2018
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Citric Acid can be used as a chelating agent (like sorbitol, sodium lactate, sodium gluconate) and is used to reduce soap scum, especially useful if you have hard water. It reacts with the lye to form sodium citrate.

Use rate is 0.1% to 0.5%. Up to 1 tsp. (1-5 grams) ppo
SAP value is 0.571 for monohydrate citric acid.
SAP value is 0.625 for anhydrous citric acid.

Add citric acid to oils before adding lye water. If you add it to your water, add the lye slowly and carefully. The citric acid will cause some excess bubbling and splashing.

When using CA in your have to add a bit of extra lye to compensate for the oils that the CA brings out of the batter...CA counteracts lye, so to make up for that, I add 0.571 oz of lye for every oz of citric acid.

so if you are using 0.25 oz of citric ppo...and making a 32 oz batch of soap:
2 (lbs) x 0.25 = 0.5 oz CA
0.5 x 0.571 = 0.2885 oz extra lye (i would use 0.3 oz)
Do you think it is okay to use citric acid and sodium lactate together?
Nov 15, 2018
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Yes, I have done that quite often. I've switched to citrate instead of CA, but the net effect is the same (since the lye turns the CA into citrate). No problems combining the two.