Citric Acid

[dippy]

I have just been reading lots of previous threads about citric acid and using it in soap. We have hard water here so thought I should try using it. I have read it goes as follows:

Typical dosage: 10 g citric acid for every 1,000 g oils (1% ppo). Range 0.1% to 3%.

Citric acid and Sodium hydroxide (NaOH) make Sodium citrate in soap
10 g citric acid neutralizes 6.24 g NaOH

I have just one question about the extra lye you add. It's 6.24g extra lye needed per 10g of citric acid added - does that mean you have to add the corresponding amount of water also that you normally add (I will be doing 33% lye concentration). Or do you just add the lye and not add any extra water as its very small amounts?

I will be using 500g oils so the lye is only 3g. I would have thought a few grams of water wont make much difference.

And for a beginner would you recommend adding the CA to the water and mixing before the lye or putting some water aside and adding it mixed with a bit of water just before trace?

 

[BattleGnome]

Add the CA to the water then add your lye. I’m not sure the CA will dissolved the lye is dissolved first.

Here‘s DeeAnna’s breakdown on using citric acid

I don’t add extra water but I also don’t often make 500g batches. I usually use 33% lye concentration in my calculations then I do the citric acid calculations and add it to my original water amount.

 

[dippy]

Thank you battlegnome! I might just leave for my test batches until I have settled on a recipe as my scales are just cheap household ones so I don't know how accurate they are.

I will add it when I start doing 1kg batches. I am doing a 7% superfat for my small batches to give me some flexibility if my scales are a little off.

 

[JillGat]

Add the CA to the water then add your lye. I’m not sure the CA will dissolved the lye is dissolved first.

Here‘s DeeAnna’s breakdown on using citric acid

I don’t add extra water but I also don’t often make 500g batches. I usually use 33% lye concentration in my calculations then I do the citric acid calculations and add it to my original water amount.

Hi! You recommend adding the CA to the water, then add lye. But DeeAnna recommends adding the CA to twice as much water and adding that to the oils. What are the pros and cons of each?

 

[BattleGnome]

Hi! You recommend adding the CA to the water, then add lye. But DeeAnna recommends adding the CA to twice as much water and adding that to the oils. What are the pros and cons of each?

I’ve never done the second method, hopefully DeeAnna will be able to chime in this weekend.

 

[JillGat]

Oh, I didn't know DeeAnna was a member here! Can somebody forward this to her? Thanks and Feliz Navidad!

 

[DeeAnna]

EIther way works. People ask for black and white advice, so that's why I give the "dissolve in water in 2 times the weight of citric acid" but any way that gets the citric acid dissolved is what works.

"...does that mean you have to add the corresponding amount of water also that you normally add ..."

That's the mathematically correct way to do it. I calculate the water weight based on ALL of the alkali (NaOH and/or KOH) to be used in the soap batch.

There is always some uncontrollable, inadvertent error in soap making, so why do I want to potentially increase this error by not accounting for everything I can reasonably account for? More or less water can alter the temperature at which the soap gels, any tendency toward making "glycerin rivers", the time I have to do a swirl before the soap gets too thick, the likelihood of developing soap ash, etc.

That said, if you are making an alkali solution that is less than 50% lye concentration, adding the extra water is not necessary from a strictly chemistry point of view.

 

[JillGat]

So there is no criteria for whether adding CA to lye water or water that goes in the oils?