Stearic Acid or Sodium Lactate?

[xxlasxx]

Can someone compare and contrast the use of these two additives?
It seems like some soap makers use SA to make a harder bar of soap, and others use SL. Is one better than the other? Are they meant for CP or HP soaps?
I'd like to try adding it to recipes that I use in my silicone molds, as I read the soap will slide out easier. I'm just not sure which is best. Thanks in advance for
any info....Lisa

 

[snappyllama]

I think this one was already covered here: http://www.soapmakingforum.com/showthread.php?t=11961

I CP and use SL (or salt if I'm out of SL) to harden my bars.

 

[Seawolfe]

I have never used SL, because the universe doesn't want me to have any. But it has GOT to be easier than stearic, which is a serious pain in the butt to melt and work with. Coating the melt container and utensils with its nastiness...

 

[CaraBou]

I have never used SL, because the universe doesn't want me to have any.

Hmmm, there must be a good story here... Even better than the one where you try working with SA, I would guess.

 

[Saponista]

I haven't used stearic acid yet but was going to give some a try as my order has just arrived. It says that it isn't very soluble in water but freely soluble in oil. Is that not the case, will I spend hours trying tondissolve it only to end up with a sticky mess?

 

[The Efficacious Gentleman]

Stearic acid is a fatty acid, like your oils are. It has a sap number and everything.

Those who make shaving soaps use a whole lot of it not as a additive but as a ingredient - the bulk of the soap in many case.

I use SL in my soaps for extra hardness when handling and so on

 

[xxlasxx]

thank you for the responses, so far!
I also looked at the above link to an archived post on this subject....I think SL might be the way to go in CP or HP. Someone posted use the SL at 3 %
Is that 3% of the total oils? Can someone provide an example? I'm still learning,so thanks for answering my newbie questions! Lisa

 

[shunt2011]

I use SL in my soap. I also use Stearic in my shaving soap and it's very difficult to work with in my opinion. I RT so I wouldn't even think of using stearic in my CP soaps.

 

[new12soap]

Stearic acid in anything other than a shaving soap* is a total PITA to work with. It will accelerate trace to the point of seizing. The melt temp is high, and for those 2 reasons it is usually melted and added separately, and that means that the second you take it off the heat it starts to cool and you leave a bit of it behind in the container. It will make your soap harder, for sure, but it will also cut back on the lather.

Sodium lactate will also make your soaps harder, and give you a more fluid pour if you are doing HP. It can also help with lather, some say it increases it, others say it just stabilizes it, but most agree it doesn't diminish it like SA can. In soaps I use 1.5 to 2% sodium lactate by weight of the oils. Above 3% SL can become exfoliating and photosensitizing in leave-on products.

If I am making a 2lb (oil weight) batch of soap (I never recommend smaller than that for beginners), that is 32oz of oils, and I would add 0.48 to 0.64 ounces of SL. Since SL is water soluble and not oil soluble I would add that to my water. I add it before the lye, you can add it after, some people add it at trace. Doesn't seem to make any difference.

*stearic acid is still a total PITA to work with in shaving soap, too, but it's a different process!

 

[DeeAnna]

"...It says that it isn't very soluble in water but freely soluble in oil...."

True, but the stearic is soluble in oil only when you heat it to its melt point (around 160 deg F). That's hotter than I normally heat my soaping oils. I'm with New12soap -- stearic is a pain to work with. I use it only in shave soaps and lotions, not in regular bath soaps. It really needs to be hot processed.

 

[xxlasxx]

thanks to all for this helpful info!!

new12soap......thank you for your detailed post!!

Lisa

 

[Seawolfe]

Hmmm, there must be a good story here... Even better than the one where you try working with SA, I would guess.

No real story, except that EVERY time I have an order in anywhere with soap supplies I try to add Sodium Lactate, and they are out. Its a sign I tell ya!

 

[shunt2011]

No real story, except that EVERY time I have an order in anywhere with soap supplies I try to add Sodium Lactate, and they are out. Its a sign I tell ya!

I have a gallon and some 1 lb bottles if you would like me to send you some.

 

[IrishLass]

I use sodium lactate @ 3% in my CP and HP, as well as my liquid soap (as per pound of oils).

In my CP it makes a harder bar, plus it enhances my lather (i.e., it makes it feel a bit creamier as if I had added milk to my formula).

In my HP it does the same but it also makes the batter more fluid for easier molding.

And in my liquid soap, it helps the liquid soap paste to dissolve easier/quicker.

I use stearic acid in my shave soaps only. If you ask me, the only thing it has in common with sodium lactate is the hardness factor, but even in that they differ from each other. Compared 1:1, I find that stearic acid makes a harder soap than sodium lactate, but it (SA) doesn't do the other nice things that sodium lactate can do.

And by the same token, sodium lactate cannot provide the same wonderful cushion/glide in my shave soap that stearic acid can.

They are so different from each other that it can never be an 'either/or' thing with me. I need them both!

IrishLass

 

[xxlasxx]

thank you for this info from your perspective, Irish Lass!!

Lisa