How long do you cure your CPOP soaps? HP?

[DeeAnna]

From the post at the MMS forum: "...You can lower your soap's pH by adding Citric Acid but then you must also up your lye to compensate for the CA or your soap will separate...."

I've read this post before and this particular statement is still bad chemistry. Citric acid reacts instantly with lye to form sodium citrate and water.

Done in the absence of saponifying soap, adding citric acid to a lye solution would lower the pH of the lye solution ONLY IF there is enough citric acid added to exactly equal or exceed the amount of acid required to neutralize the sodium hydroxide. But adding citric acid in conjunction with making soap, the chemistry just doesn't work that way. The soap has its own contribution to the party. The net effect is citric acid does not lower the soap's pH if added to a soap batter.

"...[citric acid] reacts with the lye to form sodium citrate...."

The MMS poster is correct here. Approximately 0.6 g of NaOH neutralizes 1 gram of citric acid.

If you add citric acid to a soap batter but do NOT add sufficient lye to compensate for this neutralization reaction, the citric acid will consume some of the lye needed for saponification. You are in effect increasing your superfat -- not lowering the pH.

Citric acid is not soluble in fat. It would work better to dissolve the citric acid in the water phase. I can't speak about the advisability of adding dead-sea salt to saponifying batter.

Here is yet another correction to the MMS post: "...At a pH level of "7" Dove is a true neutral pH soap...."

Nope, wrong again. Dove is a syndet (synthetic detergent) bar, NOT a soap. It can legitimately have a pH of 7 or thereabouts because it is NOT a true lye soap.

More info: http://www.soapmakingforum.com/showpost.php?p=414542&postcount=22

 

[max_ime]

Dead Sea Salt isn't really good to use in soap. It's got too many minerals that react with the lye in the soap.

I use citric acid in nearly all of my soaps. I dissolve it in my water before I add the lye, and I use the much easier conversion of 6g lye for every 10g citric acid. I use 5g citric acid for every 500g oils.

well so far dead sea salt seems to work well in the amounts I use it. about 1.6g per bar of 100-140g

Does the lye solution bubbles more or steam more, any risks of splashes by dissolving the Citric acid before the lye?

If you add citric acid to a soap batter but do NOT add sufficient lye to compensate for this neutralization reaction, the citric acid will consume some of the lye needed for saponification. You are in effect increasing your superfat -- not lowering the pH.

Citric acid is not soluble in fat. It would work better to dissolve the citric acid in the water phase. I can't speak about the advisability of adding dead-sea salt to saponifying batter.

If it is so, if it's just playing with the SF, then what is the point of using Citric acid? I have the feeling there is more to it, like it probably does help the ph to remain lower or/and the soap to be less cleansing, good if using lots of coconut I guess.

adding a citric acid solution to the oils before adding the lye solution must be pretty much the same in the end as adding the CA to the water before adding lye. Once you put the stick blender in the batter it all comes together

 

[FlybyStardancer]

Sodium citrate (what forms when lye reacts with citric acid) is a chelator. It helps bind up the minerals in hard water, which in turn allows the soap to lather more freely and for less soap scum to form. Adding the citric acid to the water allows it to dissolve more readily, and also gives it a chance to react with the lye before it gets added to the oils, allowing the whole process to run smoother. I haven't had any issues with having it dissolved in the water when I add lye. It might produce a smidge more heat than water without the citric acid, but it's really a non-event.

It does not make soaps with too high a CO level milder, nor does it truly lower the pH of the soap.

 

[DeeAnna]

Exactly what FlyBy said. Couldn't have explained it any better.

 

[CaraBou]

FlyBy, how long do you let your water/citric acid/lye solution sit before you add it to your oils to ensure maximum conversion to sodium citrate? Would a 2:1 water to "original" lye ratio still work okay, or do you need to add some extra? And finally, do you experience any fizzing or other behavior changes that I should know about before trying it?

My DH keeps citric acid for his home brewing, and I have been wanting to try it in soap. Thanks for all the great info, especially on the application rates of the citric acid and extra lye.

 

[FlybyStardancer]

I let it sit as long as I can stand, since I try to soap cooler anyways. I don't add any extra water. I've even done it with a 50/50 mixture, when I was adding the rest of the water balance as a different liquid. I just make sure the citric acid is dissolved before adding the lye, and there's no odd behavior.

I've certainly noticed a difference in my soaps.

 

[seven]

I use the much easier conversion of 6g lye for every 10g citric acid. I use 5g citric acid for every 500g oils.

Fly, can you please help me understand this better. so far, i understand that you have to adjust the amount of lye (read: add more) if you are using citric. so, lets say my recipe of 500 gr of oils calls for 50 gr lye, with a 5% SF. i want to use 5 gr of citric like you, so i need to add 3 gr more of lye to keep the SF level at 5% (so total lye will be 53 gr). am i right?

i suck at math, chem, the whole science thing

 

[FlybyStardancer]

Yup, that's exactly it!

 

[max_ime]

Dead Sea Salt isn't really good to use in soap. It's got too many minerals that react with the lye in the soap.

I use citric acid in nearly all of my soaps. I dissolve it in my water before I add the lye, and I use the much easier conversion of 6g lye for every 10g citric acid. I use 5g citric acid for every 500g oils.

with such an amount do you do CP ?

I used the same amount with HP and I have tiny air bubbles all through my soap, it seems like they form during the cooking phase. I thought it was the dead sea salt but when I tried with normal sea salt, same thing happens. Thank you!