Stearic Acid in HP siezed

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

inquebiss

Member
Joined
Sep 15, 2013
Messages
9
Reaction score
4
Location
Hawaii
Hey all, I was pretty excited to try out a new formulation of what I thought was going to be a great shave HP soap. However, once I combined the lye solution with the oil mix, the entire mixture immediately siezed and turned grainy. I tried to keep it on the heat with hopes that it would melt back down so I could cook it, but it just stayed a large pliable mass. I threw it out.

My guess is I have too much stearic acid, but I've seen others make soap that have high percentage of stearic successfully. Maybe I just did something completely wrong.

  • Kokum Butter 35%
  • Stearic Acid 30%
  • Castor Oil 15%
  • Coconut oil 10%
  • Shea Butter 10%

3% SF
38% water

Any help troubleshooting this would be greatly appreciated.
 
I had something similar happen to me a couple of times and it turned out I was adding my lye solution to quickly try adding a little bit and mix then a little more mix and keep repeating and see if that fixes it ... good luck!!! :)
 
You did nothing wrong -- what you encountered is normal when soap is made from a fatty acid. Lye reacts instantly with stearic acid, because stearic is not a "normal" fat; it's a fatty acid. It's like two lovers meeting alone -- instant attraction.

A fat is more complicated so the lye takes longer to make soap from it. The lye has to split the fat apart first into glycerin and fatty acids. THEN the lye can react with the fatty acids to make soap. This is more like two lovers meeting at a crowded party -- it takes time to find each other.

Try this --

Start with only the fats in your soap pot -- leave the stearic acid out at first. Heat the fats to about 180 deg F (80 C). Add the lye solution as you would normally do, stir the batter to a medium trace with a whisk or stick blender.

Up to this point, it's just a "normal" CP or HP soap method. Now the fun begins when you add the melted stearic to the traced batter. Switch to stirring with a spoon or spatula and finish your soap.

Yes, the stearic will cause the batter to firm up a lot, but that's to be expected. This 2 step method will ensure your soap batter is as well blended as possible with the least amount of frustration.
 
WOW!!! DeeAnna as usual you're advice, especially at the scientific angle, is amazing. I also had a similar thing and I did also add the lye solution pretty quick before stick blending. I also added the SA as it was, without melting because at the time I did not know that SA could be melted. So I guess next time I make a recipe that calls for SA (my shaving soap) I will need to take all of what has been said here into account. Great info.
 
You did nothing wrong -- what you encountered is normal when soap is made from a fatty acid. Lye reacts instantly with stearic acid, because stearic is not a "normal" fat; it's a fatty acid. It's like two lovers meeting alone -- instant attraction.

A fat is more complicated so the lye takes longer to make soap from it. The lye has to split the fat apart first into glycerin and fatty acids. THEN the lye can react with the fatty acids to make soap. This is more like two lovers meeting at a crowded party -- it takes time to find each other.

Try this --

Start with only the fats in your soap pot -- leave the stearic acid out at first. Heat the fats to about 180 deg F (80 C). Add the lye solution as you would normally do, stir the batter to a medium trace with a whisk or stick blender.

Up to this point, it's just a "normal" CP or HP soap method. Now the fun begins when you add the melted stearic to the traced batter. Switch to stirring with a spoon or spatula and finish your soap.

Yes, the stearic will cause the batter to firm up a lot, but that's to be expected. This 2 step method will ensure your soap batter is as well blended as possible with the least amount of frustration.

This is great information! I was about to start from scratch on my formula, but I will definitely try this method out first.
 
"...I also added the SA as it was, without melting because at the time I did not know that SA could be melted...."

I use stearic in lotions and it has to be melted for lotions as well as for soap to get the right consistency.

Stearic melts pretty hot -- above 180 deg F -- so I melt it (or beeswax) separately from my other ingredients to make sure it is completely melted without overheating everything else. If I were adding just a little bit of stearic (to harden a regular bath soap for example) I would then mix it into warm oils while stick blending the oils. The vigorous mixing will help eliminate any stearic (or beeswax) clumps or spots.

In a shaving soap, the stearic is such a large amount that it's impossible to blend it in with a stick blender -- the mixture gets so thick, the blender will just burn out. I just pour the stearic over the other ingredients in the soap pot and mix with a spoon or potato masher. And tell myself the whole time that soaping CAN be a good upper body workout!

Another tip is to melt the stearic in a double boiler or crock pot. It doesn't melt in the microwave.
 
"...I also added the SA as it was, without melting because at the time I did not know that SA could be melted...."

I use stearic in lotions and it has to be melted for lotions as well as for soap to get the right consistency.

Stearic melts pretty hot -- above 180 deg F -- so I melt it (or beeswax) separately from my other ingredients to make sure it is completely melted without overheating everything else. If I were adding just a little bit of stearic (to harden a regular bath soap for example) I would then mix it into warm oils while stick blending the oils. The vigorous mixing will help eliminate any stearic (or beeswax) clumps or spots.

In a shaving soap, the stearic is such a large amount that it's impossible to blend it in with a stick blender -- the mixture gets so thick, the blender will just burn out. I just pour the stearic over the other ingredients in the soap pot and mix with a spoon or potato masher. And tell myself the whole time that soaping CAN be a good upper body workout!

Another tip is to melt the stearic in a double boiler or crock pot. It doesn't melt in the microwave.

I agree, and I always melt the stearic with the other oils and butters. However, I always use a double boiler, as I don't trust a microwave. Might be my experience with doing chocolate work that discourages me from using it.

Anyways, I did find myself a solution to the seizing of the oil mix. First, I'm now using a mixed lye solution of 35% NaOH and 65% KOH. I've also increase the amount of water in the lye solution, which seems to slow down the saponification and make it manageable with a whisk. No blender needed as it reaches trace almost immediately.
 
I agree, and I always melt the stearic with the other oils and butters. However, I always use a double boiler, as I don't trust a microwave. Might be my experience with doing chocolate work that discourages me from using it.

Anyways, I did find myself a solution to the seizing of the oil mix. First, I'm now using a mixed lye solution of 35% NaOH and 65% KOH. I've also increase the amount of water in the lye solution, which seems to slow down the saponification and make it manageable with a whisk. No blender needed as it reaches trace almost immediately.

What is the texture of the soap when done? I am liking the shave soap I made, and the reviews have been pretty good, but I worry that being so soft they will dissolve too quickly.


Sent from my iPhone using Soap Making
 
Good info, DeeAnna! I have been making CP shaving soap but would like to try HP to boost the stearic. These are great tips.
 
Another tip is to melt the stearic in a double boiler or crock pot. It doesn't melt in the microwave.
Have you tried holding out a small portion of the water from your saponif'n mixture and floating the stearic acid on top of that water in the microwave oven? Should be about the effect of a double boiler but maybe faster.
 
It's messy enough when I just melt stearic by itself in the container. Adding water to the mess would be worse, IMO. But a reasonable idea in theory.
 
I HP in a crockpot and find that it behaves fairly well for me, Critterman does it the same way as I do.... slow and steady add of the lye to the batch...
 
What is the texture of the soap when done? I am liking the shave soap I made, and the reviews have been pretty good, but I worry that being so soft they will dissolve too quickly.


Sent from my iPhone using Soap Making

It is a "cream soap" consistency, soft and pliable, but it holds it's shape. It's exactly the consistency I was looking for. I plan to present it in cosmetic style jars.
 
Back
Top