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Tutorial: Shaving Soap Recipe with Stearic Acid

soap recipes and tutorials

Last year, Veronica shared her palm-free shaving soap recipe, and it's been quite the hit! However, a lot of soapmakers have been requesting two modifications:

  • A wet shaving soap formula with palm oil (not palm-free)
  • A palm free shaving soap formula without soy

Today, we're going to tackle the first request: a traditional shaving soap made with stearic acid, which is often derived from palm oil (and sometimes, animal fats.) We'll have to dive into a palm-free and soy-free version another time (but yes, it is possible!)

 Tutorial: Shaving Soap Recipe with Stearic Acid

This shaving soap recipe can be poured into a cylindrical mold and cut into bars, poured into individual cavity molds, or poured directly in tins. It's completely up to you! The soap during the pour is extremely smooth due to the higher water content, and the inclusion of sodium lactate. With each section, I've included notes as to why the formula is written how it is and should give you enough information to make decisions about making any changes!

This shaving soap recipe with stearic acid is sized for a small batch, giving you about ten shaving soaps coming in around 3.5 to 4 ounces each. You can resize it using a lye calculator for whichever mold works for you. As requested, the formula includes percentages for your convenience.

(If you aren't sure how much soap your mold holds, you can find out with this guide to resizing your soap recipes to fit your mold.)

Shaving Soap Recipe Used

  • 10.8 ounces Stearic Acid (45% of the oils)
  • 5.8 ounces Coconut Oil (24% of the oils)
  • 3.4 ounces Olive Oil (14% of the oils)
  • 2.4 ounces Hemp Seed Oil (10% of the oils)
  • 1.7 ounces Castor Oil (7% of the oils)
  • 2.78 ounces Potassium Hydroxide (5% superfat)
  • 1.67 ounces Sodium Hydroxide (5% superfat)
  • 23.36 ounces Distilled Water (16% lye solution)

I bought these soapmaking oils from Soaper's Choice.

This shaving soap recipe uses two types of lye, at a ratio of 2:3 (two parts Sodium Hydroxide to three parts Potassium Hydroxide or in other words, 40% NaOH + 60% KOH), which creates a softer soap that lathers easier. For a softer soap that will lather quicker, increase the KOH to 75% of the total lye amount and use only 25% NaOH. The lye amount is calculated at a 5% superfat, however, an additional ounce of oil will be added later that will increase the superfat to about an 8% superfat.

This shaving soap recipe also uses a lot of water (more than "full water") to give the soap fluidity for easier pouring. Since this shaving soap recipe is cooked in a crockpot, you will see some water loss and evaporation during the process, especially if you uncover the crockpot a lot! I wouldn't recommend reducing your water amount below 17 to 18 ounces (20%  lye solution).

Essential Oil Blend Used

  • 8 grams Ho Wood Essential Oil (23% of the blend)
  • 6 grams Amyris Essential Oil (18% of the blend)
  • 6 grams Folded Orange Essential Oil (18% of the blend)
  • 5 grams Atlas Cedarwood Essential Oil (15% of the blend)
  • 5 grams Turmeric Essential Oil (15% of the blend)
  • 4 grams Juniper Berry Essential Oil (11% of the blend)

These essential oils are from Liberty Natural, but you can use any fragrances or essential oils your heart desires.

Additional Additives Used

  • 1 ounce additional oil
  • 1 ounce Sodium Lactate
  • 0.5 ounce Silk Amino Acids
  • 0.5 ounces Vitamin E
  • ½ teaspoon Nettle Leaf Powder
  • ¾ teaspoon Turmeric Powder

For this specific soap, I used one ounce of Argan oil as my additional oil, but this is where you can really customize and choose your favorite skin-loving oil without worrying about throwing the formula off too much. (If you want to replace other oils in this formula, you'll need to replace them properly.)

I also added silk amino acids and vitamin E. Unlike other wash-off products and soaps, the lather of this soap will actually sit on the skin for a while and these additives add a little more love to the skin feel and post-shave skin conditioning. The sodium lactate is primarily serving as a viscosity aide, to ensure the soap is easier to pour into the mold or tins, but it has the double benefit of being a humectant, too.

I chose nettle leaf and turmeric as colorants, as well as for their purported skin benefits. However, as this soap is not a drug, no claims can be made about those benefits and their primary purpose is as a colorant.

PREP WORK: Weigh out your oils, place them in the crockpot, and set them aside.

In a lye-safe container, add both the sodium hydroxide and potassium hydroxide to the distilled water. I recommend adding the potassium hydroxide (KOH) first, as it will make a whooshing sound and bubble up a little from the amount of heat/energy created by a KOH solution. Once the KOH is fully dissolved, slowly add the sodium hydroxide and stir until dissolved.

In a glass or stainless steel jar/bowl (do not use plastic!), measure your additional oil, your essential oil blend (or fragrance), vitamin E, and your colorants (if using). These additives are all oil-soluble ingredients, so they can be prepped together.

In another container (plastic is okay here), measure your sodium lactate and silk amino acids. These additives are water-soluble additives, so they can be prepped together. Unlike cold process soapmaking, you do not want to add your sodium lactate to your lye solution. It will be added after the cook to make your soap a little easier to pour!

 The dual-lye solution, the oil-soluble additives, and the water-soluble additives prepped for the shaving soap!

GET STARTED: Turn your crockpot on to low and wait for your oils to melt. The stearic acid will take a long time to melt on its own, and you may crank your crockpot up to high for a short period of time. Do not try to melt your stearic acid by itself - it will melt faster if it's mixed with the liquid and soft oils!

Stir the oils periodically, as the movement of the oils will help spread the heat out and melt the solid oils/fats faster.

 This shaving soap recipe contains a ton of stearic acid, which has a very high melting point. The melting process will take a while!

 Add your other oils to your stearic acid, and stir the oils occasionally to prevent hot spots.

 Allow the stearic acid to fully melt before moving on to making your shaving soap!

MIX IT UP: Once all of your oils are melted, you are ready to get started! If you turned your crockpot on high to melt the stearic acid, you will want to turn it down to low. Temp your oils, and if they are below 180° F (82° C) move right along with the next step!

Slowly pour the lye solution into the oils. When you do so, your lye solution will be cooler than your oils and will create a really cool effect as the high melt point fatty acids temporarily resolidify. 

After pouring your lye solution into the oils, stick blend the lye solution and oils together. At first, they will accelerate quickly and turn into a texture similar to mashed potatoes. Keep stirring and mixing, and the shaving soap recipe will loosen back up.

Pop the lid back on your crockpot and cook the soap on low. Every fifteen minutes, stir your soap with a spatula so that the soap on the bottom doesn't burn. (Meaning check your soap after the first fifteen minutes and every fifteen to thirty minutes thereafter, keep an eye on it! Different crockpots heat differently, and you could overcook the soap!)

(Based on comments, it's become clear that everyone's crockpots and methods for keeping it covered are greatly affecting their results. If your soap begins to thicken like a taffy but has completed the other phases pictured, stop cooking it and move forward. Refer to the photos below to identify the stages, the last photo in this series is the "taffy" consistency you should be looking for. There is no harm in ending the cook "early", so don't be afraid to act!)

 When you add the dual lye solution to the hot oils, some of the fatty acids will resolidify. It looks like something is going wrong, but it's perfectly fine!

 Initially, the shaving soap recipe will hugely accelerate into the mashed potatoes phase of hot process soapmaking. Keep stirring and it will loosen back up!

 Once the shaving soap has become a nice fluid consistency, put the lid back on your crockpot and let it cook. You could move forward with additives and pouring here, if you would like.

 The thickest you should allow your shaving soap should get is like this - some translucent areas, but not all, thick but not unmanageable, still pretty wet and glossy.

WRAP IT UP: After your soap has cooked and gone through all of the above stages, turn your crockpot to the warm setting (if it has one!) Give the soap a few minutes to rest and cool down, stirring it helps!

(In my crockpot, I cooked this soap for about an hour. After lots of others soapmakers have tried it, we've discovered that different crockpots are heating the soap differently - your crockpot may run much hotter than mine! It's not harmful to "undercook" the soap, the initial heat will jumpstart saponification.)

Once the shaving soap is below 180° F (82° C), you're ready to mix in your additives and pour. It's important to be prepared. Once your temperature starts dropping, it will continue to drop dramatically. If you wait too long, the soap will start to harden and will make it difficult to pour. Be prepared, move quickly (and steadily - the soap may not be caustic anymore but it's still hot!)

Stir in all of your additives: you can add your oil phase and water phase additives separately or all together. Personally, I like to add the water phase additives first, as the sodium lactate helps loosen up the soap a little bit more. Using a stick blender will help incorporate the additives quickly!

If you are reading this before whipping up this soap, a common mistake has been adding the additives (sodium lactate, extra oil, vitamin e, essential oils, silk, etc.) before or during the cook. They should be reserved for AFTER the cook as they will help loosen the soap back up!

 Add your additives to the shaving soap, including your additional oil, essential oil blend, vitamin E, sodium lactate, silk amino acids, and colorants!

 Use your stick blender to incorporate the additives and smooth out the shaving soap!

POUR IT: It's time to mold! If you are using tins or plastic jars, you want to make sure that you are not pouring too hot (consult your supplier for a melting point on plastic packaging).

The crock is going to be hot and heavy, so if you are more comfortable using a ladle to pour the soap, please do! For this tutorial, I poured some of this shaving soap recipe into PET wide-mouth plastic jars and the remainder in a mold.

(A few soapmakers have said they use a stainless steel ice cream scoop for portioning this soap into jars or tins - smart thinking!)

 This shaving soap recipe poured into PET wide mouth plastic jars.

If you use jars and plan on selling this soap, you want to remember to weigh each jar as you pour the soap into the mold. Be prepared with a jar on your scale with the scale tared, so you can pour each jar in an assembly line fashion. If you pour into jars, you are welcome to pop the lid on the jars within 24 hours of pouring, just be sure the soap has completely cooled to prevent any condensation from forming inside the jar.

If you pour the soap into a mold, you will be able to unmold it within a couple of hours, but there's no harm in waiting until the next day like you do with the cold process. When I made the final recipe for this tutorial, I was able to remove the soap from the mold and cut it after two hours!

 This shaving soap recipe in both a jar and in a puck!

Wait, we didn't zap test this sucker?! Nope, we didn't. The amount of heat we applied to the soap and the excess water will help saponify the soap. KOH is notorious for being stubborn without added heat, but following these directions will give you enough heat for saponification to do its thing. You can still test the soap during the cook if you wish!

I recommend allowing the soap to sit for a week before using it, and doing a pH test to check for any excess alkali before using. If your pH is higher than 10, allow it to continue to mellow. If your pH is still higher than 10 after two weeks, there is probably an issue with your shaving soap: your scale may be inaccurate, need new batteries, or need to be calibrated; your lye calculations may have been incorrect, or you may not have cooked the soap long enough initially to jumpstart saponification. 

 Thick and luscious lather from this shaving soap recipe is due to the huge amount of stearic acid in the formula!

You'll want to package this soap within a week to prevent excess moisture loss and shrinkage. Your final shaving soap should be a semi-soft consistency that is pliable with a little force, which will allow it to lather quickly on a shaving brush!

If you run into issues, Molly wrote a great beginner's tutorial for hot process soapmaking in a crockpot, and it's full of great tips.

This shaving soap recipe featured in this tutorial is a hot process shaving soap recipe, it is not palm-free or vegan-friendly. If you would prefer a palm-free version of shaving soap, this tutorial would be a better fit for you! You can make this shaving soap recipe vegan-friendly by eliminating the silk amino acids and ensuring your stearic acid is not derived from animal fats. It uses a 5% superfat and a 16% lye solution. Feel free to adjust as necessary!

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