Potassium hydroxide | Learn how to make soap!

Neutralizing your soap

If you want to be truly successful making and formulating liquid soap you really need to consider purchasing a digital PH meter. I bought one from a fish supply store and it cost $80.00. You might find one cheaper on Ebay or Craig’s List but I highly recommend getting one. You really can’t successfully and accurately neutralize your liquid soap if you can’t accurately determine the PH.

I like my liquid soap to be between 8.7 and 9.7. I shoot for 9. There are several factors that will determine your resulting PH including oils used, lye excess amount, water evaporation during the cooking and water added for dilution. So even though you use the same recipe each time; it’s still helpful to meter each batch so you know exactly where you are at.

Just for example…Dr Bronner’s soap meters at about 8.5. They use citric acid in theirs. If you get a meter, take the time to test liquid soap you might run across. Real liquid soap not syndets!

I’m going to discuss two neutralizers because they are the only two I’ve used. I have not used boric acid but I understand that is similar to using citric acid as far as amounts go. But I have not used it.

Borax – Borax is actually more of a buffer and not really a “neutralizer”. It brings down the PH of liquid soap because it has a lower PH itself. Borax is also great because it helps thicken your soap, it softens hard water and helps prevent congealing (that layer of soap on top).

Even though borax is magical in liquid soap there is some controversy in using it. Some people claim it is not good to use on broken skin, children under three or sensitive skin as it can be an irritant. You’ll just need to do your research and find out if you want to use it. I have a couple of different types of liquid soap I make. One of them is thicker and uses borax and the other is a bit thinner and uses citric acid.

Citric Acid – Citric acid is a great neutralizer and easy to use. I haven’t heard of it being an irritant like borax.

You’ll need to determine the resulting PH of your soap. For this recipe using an 8% lye excess I usually meter around 9.5-9.7 PH. Heat your soap back up.

To buffer using a borax solution –
Even though I do a 8% lye excess instead of Failor’s 10%, I follow Failor’s recommendations for using borax. I make a 33% solution of borax/water and add 3/4 oz per pound of paste to my diluted soap. So I’ll boil 9 oz of water and add 3 oz of borax. You have to boil it while dissolving…it’s a sucker to get dissolved at times. It will turn to clear when ready. Since we ended up with 55 ounces of paste I’m going to add about 2.5 ounces (by weight) of this solution. Test your PH. If you want to drop it a bit more, you can add another .25-.5 ounce of the solution. If you add too much your soap will cloud up a bit. Now you can add your superfat ingredients.

To drop the PH using citric acid -
I use about 5 grams citric acid per 50 oz of paste. I weigh the citric acid in a Pyrex measuring cup and pour about 1-2 ounces of boiling water over it to dissolve. Add this to your warm soap mixture. When you add it, your mixture will look like egg drop soup. This is the result of the citric acid turning the soap it touches back into free oils. I then add my superfat ingredients and let sit over night. By the next morning the curdled soap has mixed back in and all is well. If it hasn’t… gently heat, stir and let it sit for a couple more hours. Test the PH. With this recipe it drops by about .3. So if I started at 9.5 it results in a PH of 9.2. If your soap started at a 9.7 then dissolve 10 grams and add that.

You’ll really just have to experiment and keep testing the PH. I’m happy with a 9.2.

You don’t want to add too much of the citric acid or your oils/fats will start separating out and you’ll end up with an absolute mess!

Superfating your soap

Once you’ve neutralized your soap you can stop there…or you might choose to add some superfat ingredients. There are two that I use:

Sulfated Castor Oil – Also known as Turkey Red Oil, Sulfated Castor oil is water soluble. If you were to add olive or avocado oil to your liquid soap it would simply float at the top. Sulfated Castor oil will mix into your liquid soap. I add it at 1% of diluted soap.

The only problem is that some people are allergic to sulfated products so they can’t use it. I use it in my main recipe along with borax and use only glycerin in my other recipe that I use citric acid in.

Glycerin – Glycerin makes a great superfat for liquid soap. It is a solvent (adds clarity) and provided emollient properties to your finished product. I add it at 1% of diluted soap.

For this recipe, let’s use 1% of each for our superfat.

We’ll discuss storing, fragrance, color and packaging next.

Amanda

Testing for clarity

Once your paste has cooked for 2-3 hours it is time to test for clarity. I add about 2-3 ounces of boiling distilled water to a glass Pyrex measuring cup. I take a popsickle stick and scoop out a glob of paste. Add this to the water and mix. Watch the clarity. If you’re following the above recipe you should get a pretty clear mixture- though not 100%. If it’s not clear, then cook for another 30 minutes and test again.

If your recipe has a high amount of palm, a bit of shea or cocoa butter then you aren’t going to get clear. You’ll just go ahead and move on to the dilution phase after 2-3 hours of cooking your paste.

Diluting your paste

For small batches of liquid soap (including this recipe) I simply dilute in the crock pot. If I double the recipe- I transfer the paste to a stainless steel stock pot and dilute in that.

I’m going to shout for a moment. DO NOT BOIL THE PASTE. You will read everywhere to boil the paste. This is the worst thing you can do when you dilute the paste. All you need is time, patience and warm heat occasionally.

Boiling the paste evaporates water, makes that super nasty skin on top of the paste worse and also can be dangerous if you aren’t standing over the pot to keep an eye on it. Soap being diluted boils over very easily even when you think you have plenty of head room. SO…DO NOT BOIL THE PASTE. Okay…I’m done shouting.

I cook my paste in a 7 quart crock pot. If I use the recipe from the “Liquid Soap – Let’s formulate a recipe!” post or any recipe where the paste is under about 60 oz I can dilute it in my 7 quart crock pot. Remember paste = oils + KOH + initial water. It will vary slightly because of water evaporation during the cook. Our paste equals about 55 oz.

I start cooking my liquid soap when I get home from work at about 5pm. Depending on when exactly I start cooking the paste it’s ready to add water for dilution by 9-10pm. This is perfect because then I can allow it to sit over night and work on diluting without me mixing, prodding, poking and fretting. It does take time and it does take patience.

When I am satisfied with my paste’s clarity it’s time to add some water for dilution. We’ve already calculated that our paste equals about 55 oz. For dilution, I start with adding about 60% of the weight of the paste in water. So let’s add 33 oz of distilled water.

I like starting with 60% because different mixes of oils are going to need different amounts of water to dilute. I keep a note book right by the crock pot and every time I add water, I mark it down. When you repeat a recipe you can start higher if you would like. It’s a lot easier to add more water than it is to evaporate it out. So start low.

WARNING! If you are using a crock pot for dilution never add cold/warm water to your hot steamy soap paste. It will crack your crock pot! I boil the water and then add it. If you’re using a stainless steel stock pot then you can add the distilled water cold.

Boil 30 oz of distilled water and add it to your crock pot. Chunk up the soap paste as best you can, put the lid back on, turn off and unplug your crock pot and GO TO BED! Do not leave the heat on; do not stand over it stirring every 10 minutes. Simply let it sit. In the morning when you wake up a good amount will be dissolved.

If there are still large chunks of soap paste and the soap that is dissolved is fairly thick then you know you need more water. Add 5-10 more ounces of distilled water. Since your crock pot has been off you don’t need to boil it first. Now turn the crock pot on high and heat it back up. Let it heat up until it looks like it might start to boil and turn the crock pot off. Same thing if you’re using a stainless steel stock pot. Heat the mixture up, cover and then turn off the heat source.

*You can set your crock pot to warm and leave it on for a bit. I prefer to heat it up, turn it off and let it set so I can go to work, run to the store or do whatever without worrying about it. I haven’t noticed that it dissolves quicker if you leave the heat on. Once turned off, the crock pot keeps the mixture hot for quite a bit.

Let this sit for a couple of hours. You can stir every now and then if you want. You’ll notice that a skin forms on your mixture. Simply stir it back in. Some people say to skim it off but I don’t do that. I find that with the right percentage of water it dissolves with the rest of the soap. If you boil your diluting mixture the skin is worse and sometimes never dissolves back into the mixture.

After 3-5 more hours (or in my case after 9 hours when I get home from work) check it again. If there are still soap paste blobs, break them up, add 5 ounces more of water and turn the heat back on. Keep doing this until you get all (or at least most) of the paste dissolved.

This is how I dilute…once you’ve done it a couple of times you’ll be able to modify the process to one that fits you. This works well for me because I make my paste, add water for dilution, go to bed, wake up and add more water, go to work, get home and complete it. So most of the dilution/waiting is done when I’m asleep and at work! So it works for me. Do what works for you. The bottom line is…be patient…take your time…record all of the water amounts you add and DON’T BOIL your paste!

Next we’ll talk about neutralizing and superfating your liquid soap.

Amanda