In the still of the night....2 shave soaps

[The Efficacious Gentleman]

One issue I see with your Citric Acid is that you appear to have used it at the same rate as you would (and did!) Sodium citrate. 2% CA with the right amount of lye will give you more than 2% sodium (or potassium) citrate in the end, as the lye and the citric acid combine.

I can't remember the numbers exactly, but you're looking at more like 3.4% sodium citrate instead of 2%, when you use 2% citric acid

 

[Susie]

Now I have that song stuck in my head I have been going down the rabbit hole of shave soaps here and other shave sites. I appreciate your very detailed post and am curious to see how the RBO works out. Thank you for your post and I hope your shave soap is everything you hoped it would be.

See, here's the generation gap. I think of this:

 

[gloopygloop]

Dont forget about Soduim Gluconate as a chelator, I find it far more effective than S. Citrate.

 

[Johnez]

One issue I see with your Citric Acid is that you appear to have used it at the same rate as you would (and did!) Sodium citrate. 2% CA with the right amount of lye will give you more than 2% sodium (or potassium) citrate in the end, as the lye and the citric acid combine.

I can't remember the numbers exactly, but you're looking at more like 3.4% sodium citrate instead of 2%, when you use 2% citric acid

I wasn't looking to get equal effectiveness, this is really more of a primitive "does it work?" test. The next step would have been to lower the amount and find the floor for the lowest amount I can use.

DeeAnna's suggestion says 2% is fine for either.
Perhaps I'll lower the amount for sodium citrate, I don't plan to use CA anymore as it's so much easier to add a bit of SC without the *extra lye.

How much should I use?

Typical dosage for sodium citrate is 13 g to 39 g sodium citrate powder for every 1,000 g fats (1.3% to 3.9% of total fat weight). Use more for hard water, less for soft.

How much citric acid powder is typically used?

Many soap makers use 10 g to 20 g citric acid powder for every 1,000 g fats (1% to 2% based on total fat weight).

 

[user 49910]

Dont forget about Soduim Gluconate as a chelator, I find it far more effective than S. Citrate.

Just curious... where do you purchase it? It seems to be hard to find.

 

[Johnez]

Just curious... where do you purchase it? It seems to be hard to find.

It is surprisingly difficult. This is the only site I've seen it on:

https://www.makingcosmetics.com/STA-SOGLUC-01.html?lang=default
Edit-h/t to DeeAnna for providing the citation. I wish everyone provided citations for sources!

 

[user 49910]

I think I would just stay with Sodium Citrate. The attached link to a PDF from a Swiss Chemical company shows, at least as I understand it, that in the pH range of 10 which most properly made homemade soap should be, the sodium citrate is an effective chelator against calcium, magnesium and copper.
The PDF lists Trisodium Citrate Dihydrate which is basically the same thing as sodium citrate with the dihydrate having two molecules of water.
It is sometimes referred to simply as "sodium citrate", though sodium citrate can refer to any of the three sodium salts of citric acid. It possesses a saline, mildly tart flavor, and is a mild alkali.
Here in the Southwestern US, it's calcium which is the biggest hard water metallic contributor, with magnesium being second.

FACTS: Effective chelation with Citrates and Gluconates

 

[ResolvableOwl]

FACTS: Effective chelation with Citrates and Gluconates

Good find! They present some impressive numbers in this study. Sounds like it's about time to invest into gluconate.

 

[Johnez]

Good find! They present some impressive numbers in this study. Sounds like it's about time to invest into gluconate.

Edit-SG does appear to do well, but at lower pH and temps SC+EDTA seems to work nearly or as effectively. Interesting to see SG performance really shine at very high pH, looks like it'd work very well for laundry soap.

@Professor Bernardo -thanks for sharing this!

An update on my SC soap, no more zing, a very slight sour taste. I mixed the hell out of this stuff so I'm surprised it even had a sour taste, perhaps 2% is a bit high. Very happy I am letting everything cure before trying, though it's difficult waiting!

Question for those using SC, have you experienced a sour taste during your zap test? RO, you mentioned mixing CA with the lye instead of oils, perhaps I should have done that with SC as well as I have a feeling that mixing SC into the oils caused me the same headache CA did. At least my SC batch has dried and hardened much better than my CA batch (which nearly 2 weeks in is still soft and tacky!)

 

[ResolvableOwl]

AFAIK the citrate ion itself, in addition to free protons (acidic solution) has some tart taste sensation to it, i. e. one that also persists when the acid is fully neutralised. I vaguely remember that calcium citrate is used as a “sour” flavouring in things like sweet&sour Thai Chili potato chips. You are the one who has sodium citrate at hand, you can just taste it (← dual-use emoji).

Regarding the hardness: As long as you haven't made stupid mistakes (like wrong calculation of water of crystallisation, batch water, or measurement errors), the “citrate” part of citric acid vs. trisodium citrate shouldn't make any difference at all. BUT you have extra sodium in there – welcome to the dual-lye rabbit hole! Even if it's not much, every LSer knows what dramatic effects even a mere pinch of sodium can have on the consistency of potassium soaps.

 

[Johnez]

AFAIK the citrate ion itself, in addition to free protons (acidic solution) has some tart taste sensation to it, i. e. one that also persists when the acid is fully neutralised. I vaguely remember that calcium citrate is used as a “sour” flavouring in things like sweet&sour Thai Chili potato chips. You are the one who has sodium citrate at hand, you can just taste it (← dual-use emoji).

Regarding the hardness: As long as you haven't made stupid mistakes (like wrong calculation of water of crystallisation, batch water, or measurement errors), the “citrate” part of citric acid vs. trisodium citrate shouldn't make any difference at all. BUT you have extra sodium in there – welcome to the dual-lye rabbit hole! Even if it's not much, every LSer knows what dramatic effects even a mere pinch of sodium can have on the consistency of potassium soaps.

B-b-b-but the KOH did all the work I swear! You are not kidding about the dramatic difference in consistency though. This property might come in handy for those die hard puck makers who insist NaOH is necessary to make a nice cuttable puck. Perhaps next time I can pour this into a cylinder mold and see how well it cuts. My feeling is it might crumble being as dry as it is, but worth finding out.

And yes I've tasted it, lol-I was interested in seeing if this was "normal" or a sign that this batch has failed. I swear this will all come together at some point, bumbling to get there and all.

 

[ResolvableOwl]

B-b-b-but the KOH did all the work I swear!

Well yes, it's even worse! The KOH did the hard work of saponification, and then the lazy&rude sodium ions just come along and grab stearate anions, to form hard and brittle crystals.
If you don't like it that crumbly, you might try to raise water and/or glycerol addition (plasticizer). As if you hadn't already enough tuning knobs to take care of…

 

[Johnez]

Well yes, it's even worse! The KOH did the hard work of saponification, and then the lazy&rude sodium ions just come along and grab stearate anions, to form hard and brittle crystals.
If you don't like it that crumbly, you might try to raise water and/or glycerol addition (plasticizer). As if you hadn't already enough tuning knobs to take care of…

Anions....hmm....I have so many questions but I'll go reading first.

Feels more like spinning plates at this point . A more confident version of what I'm attempting lol:

 

[ResolvableOwl]

I still use citric acid in my shave soap because the lather is just awesome.

 

[user 49910]

Not sure if I made a process error (added SC solution to oil, then added lye), but I suppose learning comes from doing, figuring out what went wrong and trying again

Why did you do it that way? Sodium Citrate is not soluble in oil at all nor alcohol either. One should always dissolve the powder additives in water for complete dispersion. There is no way that one could achieve complete solubility by mixing with oils, even stick blending when adding the lye solution as the oils will coat the individual particles of sodium citrate. That's probably where the "crumbliness" came into play... inadequate ionic interaction between the ingredients.

I am not trying to imply that I am correct in everything I do regarding the making of soap, especially shaving soaps. However, there is the fact that all of the water-soluble powders are dissolved thoroughly prior to adding the lye in the distilled water, all of them including clays and titanium dioxide.

The one thing I learned from high school chemistry class and ionic solutions is that reactions occur much easier and complete when they're dissolved completely into their respective cations and anions. (I'm sure the Resolvable Owl which comment on this... ?) Putting the sodium citrate in the oil would really stifle this ionic process, any water solution entering into the mixture would only be slightly effective dissolving the SC at this point. The SC is basically encapsulated by the oil it is mixed with. Similar to the way a good roux is made for sauces and gravies, the flour particles are encapsulated by the fats/oils prior to adding the liquid. This prevents the flour particles from becoming a sticky, gooey, mess.

 

[ResolvableOwl]

This.
Think about roux. You mix flour in butter (oily) to prevent it from drawing water/clumping/doing its starch + hot water thing. That's what you want for cooking a sauce, but not what you want in soapmaking.
It's a matter of luck if water-soluble additives in the oil phase are dispersed evenly in the final product – and do you want to rely on luck?

 

[user 49910]

This.
Think about roux. You mix flour in butter (oily) to prevent it from drawing water/clumping/doing its starch + hot water thing. That's what you want for cooking a sauce, but not what you want in soapmaking.
It's a matter of luck if water-soluble additives in the oil phase are dispersed evenly in the final product – and do you want to rely on luck?

@ResolvableOwl
Thanks for reinforcing the statement I made regarding the dissolvability of the sodium citrate in oils.
Truly, as stated by you, it is a pure matter of luck, nothing more.

 

[Johnez]

Why did you do it that way? Sodium Citrate is not soluble in oil at all nor alcohol either. One should always dissolve the powder additives in water for complete dispersion. There is no way that one could achieve complete solubility by mixing with oils, even stick blending when adding the lye solution as the oils will coat the individual particles of sodium citrate. That's probably where the "crumbliness" came into play... inadequate ionic interaction between the ingredients.

I am not trying to imply that I am correct in everything I do regarding the making of soap, especially shaving soaps. However, there is the fact that all of the water-soluble powders are dissolved thoroughly prior to adding the lye in the distilled water, all of them including clays and titanium dioxide.

The one thing I learned from high school chemistry class and ionic solutions is that reactions occur much easier and complete when they're dissolved completely into their respective cations and anions. (I'm sure the Resolvable Owl which comment on this... ?) Putting the sodium citrate in the oil would really stifle this ionic process, any water solution entering into the mixture would only be slightly effective dissolving the SC at this point. The SC is basically encapsulated by the oil it is mixed with. Similar to the way a good roux is made for sauces and gravies, the flour particles are encapsulated by the fats/oils prior to adding the liquid. This prevents the flour particles from becoming a sticky, gooey, mess.

I didn't dissolve the SC into oil directly, the SC solution was added to the oils. The "SC solution" refers to the SC dissolved in water first then added to the oil.

Perhaps it wasn't as well dissolved as I thought though, being I still experienced problems.

 

[ResolvableOwl]

It just won't dissolve, regardless what you're trying. Some clever person once found out that oil and water don't mix well. The best you can achieve is “unstable emulsion” – but why bother with two emulsions, when you could just as well get away with one emulsification?

 

[Johnez]

It just won't dissolve, regardless what you're trying. Some clever person once found out that oil and water don't mix well. The best you can achieve is “unstable emulsion” – but why bother with two emulsions, when you could just as well get away with one emulsification?

I get what your saying RO (and PB), I'll mix it into lye this weekend. Apologies if I'm getting bothersome here.

To answer your question of "why," Professor Bernardo:

Per DeeAnna

https://classicbells.com/soap/citrate.asp

How should I add it to my soap?

Dissolve the citrate in about 2 times its weight of water. Stick blend that mixture into your oils.