Sodium Lactate

[scotsman]

I've been experimenting with different additives in my soap lately. Not because I find my soaps are lacking in anything. It's more just for fun than anything else. I have a curious mind and always like to experiment with different things. One of the additives I've been playing with lately is sodium lactate. I've been trying to find a good standard usage rate for cp soap. In my research I've seen people list usage rates anywhere from 1% to 8%. Are those percentages based on oil weight or total batch weight? I've been going with percentage of oil weight in my experiments and have had some decent results, but nothing as mind blowing as some people online describe it. First, I tried it at 1% with no real noticeable difference. 2% & 3% brought more noticeable results, but nothing I would consider significant. At 4% I noticed that I could de-mold the soap a few hours earlier than normal and it seemed a bit firmer than normal after the first week of cure. For those of you who use SL regularly, what usage rate do you use to get significant results? I've got a fairly large bottle of the stuff so stock to experiment with won't be an issue. I'm looking more for a shove in the right direction. My goal is to hopefully be able to de-mold my soap in 12 hours instead of 24 and minimize shrinkage from curing a good deal so the bars fill out my packaging a bit more without having to design and build molds to larger dimensions. I was thinking of trying 8% in my next test batch to see what happens. Is this too much? Should I go with a lower amount? I've read that over use can make the soap crumbly. I definitely don't want that, lol!

 

[shunt2011]

I use 2-3% and am unable to unmold from my silicone liners in 18 hours or so. I've not tried it higher. am curious to see if anyone has and how it affected the soap. I've mostly found that it just makes it easier to unmold but not harder log term.

 

[new12soap]

I use sodium lactate at 1.5% of my oil weight. I find that is enough to firm up my bars a little more quickly, I like the feel it brings to the soap, and since I primarily HP it helps with fluidity of the pour. That 1.5% is actually a 60% solution of SL, not pure SL powder.

It is NOT recommended for use at anything over 3% even in rinse off products as it can be an irritant, exfoliating (not in a good way), and a sensitizer. eta: that is based on my research/reading, YMMV. If you decide to try it at a higher rate just be aware of potential issues, that's all

A harder bar that can be unmolded more quickly is probably best accomplished in your formulation. To minimize shrinkage you may want to take a water discount.

 

[IrishLass]

I use it @ 3% ppo (I use the liquid kind that's in a 60% solution).

Also important to mention is that I use no more than a 33% lye solution when I use the sodium lactate at 3% in my CP. I found that if I use a higher lye concentration than that (i.e. less water to lye ratio), the 3% amount of sodium lactate causes a little bit of crumbling around the edges of my soap when I go to cut it. So, whenever I use a higher lye concentration, I just lower the sodium lactate %.

As far as noticing differences goes, I think it will vary from person to person and from formula to formula. In my own formulas, 3% sodium lactate ppo gives my formulas a hardness boost and makes unmolding a breeze, and it also enhances my lather. It doesn't make it bubblier, per se, but it makes it feel more 'oomphy'. Another way of putting it is that it gives my lather more 'body'.

It also makes my HP more pourable (I use it @ 3% in my HP, too).

Oh- and I mix it in with my lye water (whether doing CP or HP).

IrishLass

 

[Crombie]

I go by the hardness scale in Soap Calc. For hardness under 40 I use SL at 2% PPO; for over 40, I use at 3% PPO.

Cathy of Soaping 101 did a YouTube video showing what happens with differing amounts. Amounts 3% and up could actually make your soap softer.

 

[GrumblyGoats]

Hello IrishLass!

I've been trying to figure out how to determine the sodium lactate usage rate in relation to the water/lye ratio, and I think your input really helped:

"I use no more than a 33% lye solution when I use the sodium lactate at 3% in my CP... whenever I use a higher lye concentration, I just lower the sodium lactate %."

If it's a 33% lye solution, that is a water:lye ratio of 2.03:1. Prior to reading your comment, I came up with this:

Water:Lye = sodium lactate usage rate (% of oil weight)
1.1:1 = 1.2%
1.2:1 =1.4%
1.3:1 = 1.6%
1.4:1 = 1.8%
1.5:1 = 2%
1.6:1 = 2.2%
1.7:1 = 2.4%
1.8:1 = 2.6%
1.9:1 =2.8%
2:1 = 3%
(keep sodium lactate at 3% for anything over 2:1)

Is that a good starting point? Haha, obviously it's not really necessary to use sodium lactate for anything below a 1.5:1 ratio

 

[shunt2011]

Hello IrishLass!

I've been trying to figure out how to determine the sodium lactate usage rate in relation to the water/lye ratio, and I think your input really helped:

"I use no more than a 33% lye solution when I use the sodium lactate at 3% in my CP... whenever I use a higher lye concentration, I just lower the sodium lactate %."

If it's a 33% lye solution, that is a water:lye ratio of 2.03:1. Prior to reading your comment, I came up with this:

Water:Lye = sodium lactate usage rate (% of oil weight)
1.1:1 = 1.2%
1.2:1 =1.4%
1.3:1 = 1.6%
1.4:1 = 1.8%
1.5:1 = 2%
1.6:1 = 2.2%
1.7:1 = 2.4%
1.8:1 = 2.6%
1.9:1 =2.8%
2:1 = 3%
(keep sodium lactate at 3% for anything over 2:1)

Is that a good starting point? Haha, obviously it's not really necessary to use sodium lactate for anything below a 1.5:1 ratio

Hello and welcome! This post is 3 years old. Fortunately IL is still around.

You can utilize whatever percentage of SL that works for you. I personally use 2%-3% regardless of my lye concentration more on the formula like a higher liquid oil usage than my normal recipe. I like that it makes it all the easier to remove from my silicone liners. I also generally stick to 33% mostly.

 

[IrishLass]

Is that a good starting point? Haha, obviously it's not really necessary to use sodium lactate for anything below a 1.5:1 ratio

Welcome GrumblyGoats! I would say that's a good starting point.


IrishLass

 

[GrumblyGoats]

Thanks IrishLass! And thus far this starting point seems to be working well I had to increase the water content for one of my recipes to give me more time for the pattern I was aiming for, but that little extra water resulted in pretty soft soap (I'm a little impatient , however, using my little SL usage rate chart really helped!

 

[GrumblyGoats]

Thanks Shunt2011! I often use large water discounts (because, for the most part, I've been doing fairly simple patterns where I'm able to work fast enough that I don't have to worry about the batter thickening up too quickly), but I've started doing slightly more advanced techniques, so, because I didn't want to increase the amount of soft oils in my formula, I increased the amount of water instead to give me more time, but then it takes waaay longer for the soap to harden enough for me to unmold/cut it. Using my chart as a reference for this particular formula really helped--I was able to handle/cut it the following day.