Monday, January 18, 2010

NaOH Biodiesel Glycerin (BDG) (Hybrid) Gel Soap

Believe it or not you can use your NaOH (sodium) based BDG to make a liquid or gel soap. This is possible because the NaOH BDG has saponifiable ingredients left in it. These saponifiable elements will be turned into KOH soaps. The soap will be a really nice gel soap at a 50:50 soap to water dilution. The soap will be a thickened liquid or gel because the sodium soaps will act as the thickener in the soap. There will be no need for any thickeners such as borax.

The trick to this working just right is full saponification of the saponifiable elements left in the NaOH BDG. If you do not fully saponify the BDG you can end up with a thin liquid that will congeal into a mass. No amount of dilution will give you a nice liquid or gel.

To be sure you have fully saponified your BDG you should do a SAP test on your BDG. This way you know exactly how much KOH it will take to fully saponify your NaOH glyceirn.

This recipe is a very basic recipe. Once you have mastered this recipe you can go on to adding any other ingredients to add properties to your gel.

You will need the following;
  • 32oz NaOH BDG
  • KOH SAP value for your NaOH glycerin
  • 1.6oz KOH (26% SAP used)
  • 32oz Distilled water
  • pH Paper


Melt your NaOH BDG.



Mix your KOH caustic water.



Add the caustic water to your melted BDG and mix with a stick blender for about 5 minutes. Notice that the BDG will go from a dark brown color to a tan color. This indicates that the saponifiable elements in the BDG are starting to be saponified.





Heat the soap to 180*F and hold it there until the soap neutral and has a pH around 10.5. This could take up to 3 hours. Check the pH of the soap every 30 minutes or so. You should notice the soap go from the light tan color back to a translucent brown color.



Allow the soap to cool.



The soap should be very thick and transparent. The pH should be between 10 and 10.5. If the soap is still thin or the pH is less than 10 you will need to add more caustic (KOH) water. Mix 1/2 ounce of KOH with 3 ounce of distilled water. Add this 1 Tablespoon at a time until the soap thickens and the pH is between 10 and 10.5


To learn more about soap making from Biodiesel glycerin, be sure to check out our great book "Making Biodiesel Glycerin Soaps". It contains lots of great tips & tricks for getting the best soap out of your Biodiesel glycerin. Click here to learn more.

Happy Soaping :)

Copyright Knice-N-Clean Soap Company LLC 2010 All rights reserved

Saturday, January 16, 2010

Melt & Pour (MP) soap from rebatch material.

*** 01/16/2010 Updated to include transparent soap at the end of this post ***

I have been playing with making MP soap from BDG. One of the methods I've been using to experiment with is by using bar soap scraps. I did a re-batch of both of the bars of soap from the last blog. One of them is a BDG bar and one is a bar made by Kimberly Natures Art.



I am aiming only for a bit of added transparency, my main goal is to lower the melting point of the soaps. Most cured soap needs to be heated close to 200*F and cools very quickly. It also, as I've found, tends to melt your molds.

Transparent soap is not much more complicated but it takes more solvent. If you do not have a high ratio of stearic, palmitic, myristic or lauric acid in your soap the soap can get rather soft. In addition recipes with castor oil turn out much more transparent due to the fact that castor oil also acts like an alcohol.

Making re-batch MP is super easy. For your recipe you only need to weigh out your scraps and add 20% alcohol. That's it.. Really...
  • Put your scraps into a microwave safe container.
  • Microwave them with short 30 second bursts until the soap gets sticky.
  • Add some of the heated soap to your alcohol then pour that back into your container.
  • Microwave that with short 15 second bursts stirring after each burst.


Sticky Soap


Adding to alcohol


You will end up with a soap broth that looks similar to the following pics.




Notice the "new" melt point of the soap.



Here is how easily it pours.





Here are a few pics of the soaps setting up.





And the final bars. Remember I was only shooting for MP not transparency, but you can clearly see a shift into transparency in both bars.





I decided to see what it would take to make Kimberly's soap transparent. I used hers because I have already done this with my BDG soaps.

I used 40% alcohol and 5% more water this time and this is the result. A really nice and firm golden soap. The golden color came from the oleic acid that Kimberly used to make the soap.

I ended up using the extra water because the soap did not want to dissolve into the alcohol, instead it looked sort of like boiling oatmeal or taffy. I have found when this happens just a little bit of water is needed to correct this.




To learn more about soap making from Biodiesel glycerin, be sure to check out our great book "Making Biodiesel Glycerin Soaps". It contains lots of great tips & tricks for getting the best soap out of your Biodiesel glycerin. Click here to learn more.

Happy Soaping :)

Copyright Knice-N-Clean Soap Company LLC 2010 All rights reserved

Traditional Ingredients BDG Experiment

Recently I did an experiment with Kimberly of Natures Art. Kimberly came across some glycerin and was looking for some ideas. I asked her if she was willing to do an experiment with some of the ingredients that I use with BDG. She kindly accepted.

I was interested in comparing soaps made with the same ingredients as I sometimes use with BDG soaps. She used the same fatty acids that were used in the BDG recipe. In place of the BDG she used regular glycerin and oleic acid. Our BDG is high in oleic acid soaps due to the oils commonly used to make biodiesel in my area.

Other than the color the soaps are almost identical in properties. This experiment has helped me in that I had assumed there were a high ratio of soft oil soaps in the BDG. Kimberly's soap showed the same thing with no BDG using traditional ingredients.

Here is a picture of the BDG and Traditional ingredients side by side.




To learn more about soap making from Biodiesel glycerin, be sure to check out our great book "Making Biodiesel Glycerin Soaps". It contains this SAP test method and many more great tips & tricks for getting the best soap out of your Biodiesel glycerin. Click here to learn more.

Happy Soaping :)

Copyright Knice-N-Clean Soap Company LLC 2010 All rights reserved

Saturday, January 9, 2010

Fixing Layered NaOH BDG Liquid Soap


I recently received a liquid soap made by a fellow BDG soaper.

He is unhappy with his liquid because it has 2 layers. One really nice clear layer on the bottom and a really greasy opaque layer on the top.

I am going to try to work out what went wrong with his soap. I suspect it has something to do with unsaponified elements.

Notice the layer on the top of the soap. This soap was made from NaOH glycerin saponified with KOH so it has already been "Thickened". If the soap had not been thickened this layer would appear at the bottom of the soap. In less severe cases the soap would just be cloudy.

Unsaponified ingredients cloud the soap but when it reaches a saturation point the unsaponified ingredients float to the top in thickened soaps and fall to the bottom with non-thickened soaps. This process is also known as sequestering.

Sequestered material is not always unsaponified ingredients but in this case that is what I suspect.

Stay tuned... I will be attempting to "fix" this soap.

=== Updated 01/11/2010 ===

What I've found is that this soap was not fully saponified. The first indicator was the pH of the soap. The pH was really low being just above 8. A low pH doesn't always mean that you have saponifiable elements left, it's just a good indicator. Your pH could be as high as 10.5 and you could still have saponifiable elements left in your soap.

You can read a bit about pH or caustic testing your soap at Knice-N-Clean.com.

I took a sample of the soap and ran a SAP test on it and found that it needed another 2 grams of KOH caustic for the soap sample in the first photo. That is actually quite a bit. If a SAP had been calculated on the BDG prior to making the soap this could have been avoided.

You can find out more about working out a SAP for your BDG in our book "Making Biodiesel Glycerin Soaps".



Notice how the soap gets very cloudy and opaque during saponification. This is normal and will remain cloudy until saponification is complete. I hot processed (HP) the soap to speed up saponification and I was able to finish the soap with less than 30 minutes of cooking. You can also cold process (CP) the soap but it could take anywhere from overnight to a few weeks for saponification to complete.

Other indications that this soap was not fully saponified are;
  • The soap felt really greasy when you washed with it.
  • There was a foul undertone odor in the soap, it is possible that the soap had enough superfatting to cause the soap to start becoming rancid.
  • The soap lacked a nice lather.

This is the final soap. The soap now has a pH of 10.5. It has a nice feel when washing and the greasiness is gone. The foul undertone odor is gone and the soap has a really nice lather. The soap is also a bit thicker and now is a very nice viscous gel.



Notice the clarity of the soap. It's just a bit brighter than before and has a really crisp look to it.


To learn more about soap making from Biodiesel glycerin, be sure to check out our great book "Making Biodiesel Glycerin Soaps". It contains lots of great tips & tricks for getting the best soap out of your Biodiesel glycerin. Click here to learn more.

Happy Soaping :)

Copyright Knice-N-Clean Soap Company LLC 2010 All rights reserved