“Mechanic soap” usually refers to extra scrubby bars. The exfoliants help remove grease and oil from working hands. For these bars, I added 5 tablespoons of pumice and 8 tablespoons of walnut shells for plenty of exfoliation. Both pumice and walnut shells are effective yet fine grained, so they are not overly scratchy. These bars are be suitable for the body, but I wouldn’t recommend them for gentle facial skin. They are great for rough spots like elbows, knees and heels.
I kept these bars no-fuss with no colorants or fancy design. Sometimes, simple is best. The walnut shells give a natural warm hue. When the orange 10X essential oil is added, it turns the batter a rich orange, but I found it faded as the soap hardened. The pumice does not affect the color greatly, but it does cause the soap batter to accelerate. Prior to adding the pumice at trace, I recommend dispersing it in oil to help get rid of clumps.
I used my melted and mixed soaping oils to disperse the pumice, rather than adding extra oil to the recipe. This is a personal preference. Normally, I use extra lightweight oil to disperse my colorants and consider the dispersion oils a little extra superfat. For this recipe I did not want to add 5 whole tablespoons of extra oil because I wanted these bars to be nice and cleansing (and remember, any extra oils = weigh down lather and make rinse-off not as easy and fast). This recipe is already formulated with a 5% superfat, and contains a 12% water discount to help these bars cure faster. Read more about water discounting soap here.
What You’ll Need:
12 Bar Round Silicone Mold
9.6 oz. Coconut Oil (30%)
9.6 oz. Olive Oil (30%)
9.6 oz. Palm Oil (30%)
1.6 oz. Castor Oil (5%)
1.6 oz. Cocoa Butter (5%)
9.4 oz. Distilled Water (12% water discount)
4.6 oz. Sodium Hydroxide Lye
1.7 oz. Orange 10X Essential Oil
5 Tbs. Pumice
8 Tbs. Walnut Shells
Click here to add everything you need for this project to your Bramble Berry shopping cart!
Find the supplies you need for this project below
If you’ve never made Cold Process soap before, stop here! I highly recommend checking out our FREE four part SoapQueen.tv series on Cold Process Soapmaking, especially the episode on lye safety. And if you’d rather do some reading, Bramble Berry carries a wide range of books on the topic, including my newest book, Pure Soapmaking. You can also checkout the digital downloads for that instant gratification factor.
SAFETY FIRST: Suit up for safe handling practices! That means goggles, gloves and long sleeves. Make sure kids, pets, and other distractions and tripping hazards are out of the house or don’t have access to your soaping space. Always soap in a well-ventilated area.
FRAGRANCE PREP: Measure 1.7 ounces of orange 10X essential oil into a glass, fragrance oil safe container. Set aside.
ONE: Slowly and carefully add the lye to the water and gently stir until the lye has fully dissolved and the liquid is clear. Set aside to cool.
TWO: Melt and combine the coconut oil, cocoa butter, castor oil, palm oil, and olive oil (remember to fully melt then mix your entire container of palm oil before portioning). Once the lye water and the oils have cooled to 130 degrees or below (and are ideally within 10 degrees of each other). Place 5 tablespoons of pumice in a small container, and add 5 tablespoons of the soaping oils into the container and mix together. Doing so helps get rid of clumps, without adding too much extra oil into the soap. Set aside.
THREE: Add the lye water to the oils and stick blend until thin trace. If you’d like a harder bar of soap that releases faster from the mold, you can add sodium lactate to the cooled lye water. Use 1 teaspoon of sodium lactate per pound of oils in the recipe. For this recipe, you’d add about 2 teaspoon sodium lactate.
FOUR: Once you’ve reached a thin trace, add the orange 10X essential oil and use the stick blender to mix in. Alternate using short bursts and stirring with the blender to avoid over stick blending.
FIVE: Add the pumice mixture into the soap, and use the stick blender to mix in. This will cause the mixture to thicken.
SIX: Add 8 tablespoons of walnut shells and use a whisk to fully mix in.
SEVEN: If your batter is thin enough to pour, fill each cavity evenly. My batter was quite thick thanks to the additives and water discount, so I used a spoon to fill each cavity. Tap the mold firmly on the counter to help eliminate the air bubbles (make sure those goggles are on; beware of splashing soap when tapping). Spritz the soap with 99% isopropyl alcohol to help eliminate soda ash.
Allow the soap to stay in the mold for about 2-3 days. Unmold, and allow to cure for 4-6 weeks. I used the Soap Shaver to clean up the sides and top of the soaps, but this is optional.
Have you ever made super scrubby bars before? What kind of exfoliant did you use? Any ingredients you LOVE for mechanic’s hands?
Click to View the Recipe
- 12 Bar Round Silicone Mold
- 9.6 oz. Coconut Oil
- 9.6 oz. Olive Oil
- 9.6 oz. Palm Oil
- 1.6 oz. Castor Oil
- 1.6 oz. Cocoa Butter
- 9.4 oz. Distilled Water
- 4.6 oz. Sodium Hydroxide Lye
- 1.7 oz. Orange 10X Essential Oil
- 5 Tbs. Pumice
- 8 Tbs. Walnut Shells
- Slowly and carefully add the lye to the water and gently stir until the lye has fully dissolved and the liquid is clear. Set aside to cool.
- Melt and combine the coconut oil, castor oil, cocoa butter, palm oil, and olive oil (remember to fully melt then mix your entire container of palm oil before portioning). Once the lye water and the oils have cooled to 130 degrees or below (and are ideally within 10 degrees of each other). Place 5 tablespoons of pumice in a small container, and add 5 tablespoons of the soaping oils into the container and mix together. Doing so helps get rid of clumps, without adding too much extra oil into the soap. Set aside.
- Add the lye water to the oils and stick blend until thin trace. If you’d like a harder bar of soap that releases faster from the mold, you can add sodium lactate to the cooled lye water. Use 1 teaspoon of sodium lactate per pound of oils in the recipe. For this recipe, you’d add about 2 teaspoon sodium lactate.
- Once you’ve reached a thin trace, add the orange 10X essential oil and use the stick blender to mix in. Alternate using short bursts and stirring with the blender to avoid over stick blending.
- Add the pumice mixture into the soap, and use the stick blender to mix in. This will cause the mixture to thicken.
- Add 8 tablespoons of walnut shells and use a whisk to fully mix in.
- If your batter is thin enough to pour, fill each cavity evenly. I found mine was quite thick, so I used a spoon to fill each cavity. Tap the mold firmly on the counter to help eliminate the air bubbles. Spritz the soap with 99% isopropyl alcohol to help eliminate soda ash.
- Allow the soap to stay in the mold for about 2-3 days. Unmold, and allow to cure for 4-6 weeks. I used the Soap Shaver to smooth out the textured top of the soaps, but this is optional.
How do you think this recipe would behave as a rebatch. I need to try to make immediately and don’t have the luxury of waiting 4-6 weeks.
Sandra
You can make this recipe using the rebatch method if you like. Just add the exfoliants and scent when the soap is finished heating and pop it into molds.
You can use any of our bases: https://www.brambleberry.com/Rebatch-Bases-C14.aspx
Learn more about rebatching here: http://www.soapqueen.com/bath-and-body-tutorials/cold-process-soap/soap-queen-tv-presents-how-to-make-rebatch-soap-2/
Thank you for this post. I had a challenge from a ‘grease monkey’ friend to make a soap for mechanics, so this base you provided is a helpful starting point. I do have a question though: What is the grit (or mesh#) of the walnut shells used? It appears from a quick search that there is a plethora of grit sizes for this stuff.
These walnut shells have a nice fine texture. They are a 40/100 grit size.
I am looking at using a PVC tube for my soap. Can I coat the tube with mineral oil to aid in removal? I also would like to use pecan shells instead of walnut (I’m a Southern gentleman)…
It is possible to use a PVC tube for soap but it can be tricky to unmold. You can definitely use mineral oil or cyclomethicone to help it slide out. You may also try lining it with plastic wrap so you can grab onto that and unmold. If it’s not wanting to budge, try to find an item that’s a little smaller than the mold itself (like a can) and try pushing it out from the bottom.
Cyclomethicone: https://www.brambleberry.com/Cyclomethicone-P4560.aspx
Also, pecan shells will work just fine. Just make sure they’re finely ground.
I couldn’t wait to make this soap. It was a huge hit at my first craft fair. I market it for dirty hand and those dry flaky feet and elbows. It behaved well and I got a great pour. Didn’t have to trim sides or top. I am adding this wonderful soap to my line. Thanks for a wonderful creamy scrubby soap.
That’s awesome, so glad to hear this soap is flying off the shelves.
I would like to use the walnut shell powder in the Sea Clay Swirl soap for a mild exfoliant. How much walnut powder should I use? I’d like it to me mild but I’m afraid to put too little and not have it show up at all.
You can start with about 1 teaspoon per pound. Walnut shells are a bit more scrubby, so that should be enough for some good exfoliation. If you want more, you can add from there.
Walnut shells: https://www.brambleberry.com/Walnut-Shells-P4531.aspx
Thanks.
can you please tell me what i sub for the palm oil
Palm oil adds some great firmness to your soap, and there is no direct replacement for it. You can add certain oils and butters to help firm your soap up though. For instance, adding a hard butter, like cocoa butter up to 15%, can harden the bars. You can also add coconut oil or tallow up to 33%.
Read more about common oils and what properties they add to soap here: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/free-beginners-guide-to-soapmaking-common-soapmaking-oils/
This post on substituting oils has some great information too: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/how-to-substitute-oil-in-cold-process-recipes/
Sodium lactate is helpful as well. It helps the bars unmold more quickly. You can add 1 tsp. of sodium lactate per pound of oils to your cooled lye water. Read more in the Sunday Night Spotlight: Sodium Lactate: http://www.soapqueen.com/bramble-berry-news/sunday-night-spotlight-sodium-lactate/
Here are some links to palm-free recipes you may like:
Palm Free Vertical Twist: http://www.soapqueen.com/bath-and-body-tutorials/cold-process-soap/palm-free-vertical-twist-tutorial/
Palm Free In The Pot Swirl: http://www.soapqueen.com/bath-and-body-tutorials/cold-process-soap/a-palm-free-in-the-pot-swirl/
Formulating Cold Process Recipes: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/formulating-cold-process-recipes/
-Kelsey with Bramble Berry
Soybean oil has been working very well for me
I’ve made the switch to Leaf Lard (not grocery store brand), and Tallow. I LOVE the way my bars feel now. The bars are feel smooth, creamy, lathers lovely and my hands feel amazing. I still have soaps available for vegan options but all my other recipes now are replaced with Lard and Tallow (along with other butters and oils) instead of Palm. I’m getting great reviews from customers also. Maybe this is an option for you? I personally do not like the “store bought Lard” as it has additional preservatives added and it doesn’t (just my experience) feel as nice (I experimented with store bought Lard first). Goodluck. Happy Soaping
Quick question. Husband wants me to make this, but suggested using Orange Juice instead of water and Orange EO. Do you think this would work?
Using orange juice in place of the essential oil will change this recipe quite a bit. Because of the natural sugars, it will accelerate trace and can caramelize, causing discoloration. It will also add little to no scent. However, ingredients with sugar to add nice lather to soap! Learn more about working with fruit here: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/how-to-add-purees-to-cold-process-soap/
If you’d just like the orange scent, I would definitely recommend the essential oil. It’s super concentrated and adds a lovely citrus note. 🙂
10X Orange Essential Oil: https://www.brambleberry.com/Orange-10X-Essential-Oil-P4441.aspx
-Kelsey with Bramble Berry
Hi Brambleberry,
I am making these and going to do a swirl of activated charcoal, what other essential oils work for cleaning I know orange is the ultimate I only have 2 oz what else would do the job? I have Lavadin and Pink Grapefruit and Anise, Rosemary, Lemon, Lavendar,peppermint,clove, cinnamon
😊 Thank you
Any of those would smell really nice in this recipe! Orange and peppermint give you that classic clean and fresh smell. 🙂
Find out how to blend essential oils safely here: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/how-to-blend-essential-oils-safely/
-Kelsey with Bramble Berry
I have a question. I made this for my husband who is a mechanic. He raved about the cleansing properties and uses it often. The only issue he has is that he sometimes gets cuts and scratches on his hands and he says the exfoliants burn in those scratches. Is there something I else can make or something I can substitute that would retain the cleansing power of the bar but reduce or eliminate the unpleasantness?
Reducing the amount of walnut shells may help! Walnut shells are larger grained, so they will be very scrubby. That rough exfoliation can irritate the cuts. I would recommend trying a batch with around 5-6 Tbsp. of walnut shells to see if that helps. 🙂
-Kelsey with Bramble Berry
I also plan to make this next week and I am putting it in your 12″ column mold. I have the recipe recalculated to fill it.
When would you suggest I remove and cut it into bars?
This recipe will harden fairly quickly because of all the additives! If you wait too long to cut it, it can crumble. I would recommend lightly tapping the soap after 2 hours (make sure to wear gloves!) If it’s firm to the touch, you can unmold and cut. If not, wait another hour and check again. 🙂
-Kelsey with Bramble Berry
Can I replace the water with goats milk? Wasn’t sure about when the water is reduced in a recipe.
You can! You can use goat milk at the full recommend Lye Calculator amount, or you can use it at the discounted amount we used above. Just make sure to keep it cool so it doesn’t scorch. 🙂
Read more about working with milk here: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/how-to-add-lye-to-milk-for-cold-process-soap/
-Kelsey with Bramble Berry
I used sea sand and coffee powder!
That sounds like an awesome combination! Nice and scrubby. 🙂
-Kelsey with Bramble Berry
HI – i love your page and tutorials. I have a question. If you are doing cold process soap and want to add peppermint or lavendar leaves, what is the best point in the process to do so? And will it change color of soap?
We like to add lavender buds and other additives at thin trace! That way they mix in easily. They won’t affect the color, but the buds themselves do turn brown in the soap and can create a little halo of color around them. That’s something to keep in mind. 🙂
-Kelsey with Bramble Berry
I have made my first batch of soap, i used this recipe, but only added 2 oz of sweet almond oil and put only 6 oz of coconut oil. I guess it turned out ok, except i left it uncovered and it went thru partial gelling. I was wondering, would it be ok in the future to put it in the oven on 170 degrees, so it would go thru the whole gelling process? If so, how long should i leave it in there for?
Thank you very much for your answers.
I am sorry, I put a comment under wrong recipe, I meant to leave it under simple and gentle recipe.
You can put it in the oven on 170F if you like! That is called the Cold Process Oven Process Method, or CPOP. You can leave the soap in there for an hour, then turn the oven off and leave the soap in overnight. Read more about CPOPing soap here: https://www.soapqueen.com/bath-and-body-tutorials/cold-process-soap/hot-process-series-cpop-swirls/
You can also cover the mold with a towel, then put it on a heating pad set to medium for 20 minutes. 🙂
Learn more about gelling soap here: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/when-to-insulate-handmade-soap/
-Kelsey with Bramble Berry
Simple and Gentle Cold Process Soap: https://www.soapqueen.com/bath-and-body-tutorials/cold-process-soap/back-to-basics-simple-gentle-cold-process-soap/
Thank you very much for your answers. I love your website and your recipes.
You’re welcome Ilona! 🙂
-Kelsey with Bramble Berry
I am sorry for asking so many questions, but I have one more. Currently Bramble berry is out of pumice, is there something else i can substitute it with?
You can use colloidal oatmeal or bamboo extract! They are both fine exfoliants like pumice. 🙂
Colloidal oatmeal: https://www.brambleberry.com/Colloidal-Oatmeal-P5565.aspx
Bamboo extract: https://www.brambleberry.com/Bamboo-Extract-Powder-Light-Exfoliant-P3714.aspx
Read more about exfoliants here: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/all-about-exfoliants/
-Kelsey with Bramble Berry
Can you please tell me how many tablespoons is one ounce of Walnut Shells and also of Pumice. Recipe is in tablespoons and it is sold in ounces, I don’t know how much to buy.
THank you
Hi Ilona!
Because the walnut shells and pumice are volume measurements, I can’t tell you exactly how much they weigh. However, the kit comes with 3 ounces of walnut shells and 1 ounce of pumice. That is more than enough for this recipe! 🙂
-Kelsey with Bramble Berry
Hello. Just wanted to leave a little update. 1 ounce of Pumice is 4.5 tablespoons and 3 oz of walnut shells are 7.5 tablespoons. Almost enough for the recipe.
Also I have a question. I put mold on heating pad and have covered with blanket. Apparently it has been to much and soap cracked after being covered for 4 hours. I then sprayed with alcohol and somewhat fixed the crack. I am very experienced in this, but does it mean that orange essential oil adds to the heat? Because i didn’t cover for the other recipe and it only went thru partial gel.
Thank you
We double checked the kit and found the walnut shells were exactly 3 ounces, but the pumice was a little under. I am so sorry about that. We added another ounce of pumice to the kit. Thank you so much for letting us know.
Also, I think the cracking was a mixture of temperature and the exfoliants in this recipe. The walnut shells and pumice make these bars harden very quickly. So I think that coupled with the heat caused the cracking. For your next batch, I would recommend leaving these bars at room temperature, or using just the blanket or just the heating pad. That should keep them a bit cooler. Also, the bars should be just fine to use. 🙂
Read more about why soap cracks here: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/why-did-my-soap-crack/
-Kelsey with Bramble Berry
Would this soap be ok, if i put it into rectangular mold and then cut soap? Is so, how long to wait before cutting?
I think that would be just fine! As you’re spooning the soap into the loaf mold, make sure to tap it several times on the counter. That will help get rid of the air bubbles trapped in the thicker soap. Then, let the soap sit for 1-2 days and check on it. If it’s firm to the touch, you can cut it! If it’s still fairly soft, let it sit another day or two and try again. 🙂
-Kelsey with Bramble Berry
I plan to make this next week and I am putting it in your 12″ column mold. I have the recipe recalculated to fill it.
When would you suggest I remove and cut it into bars?
Is there any way to change this to a melt & pour instead of cold process?
You can use melt and pour for this soap! The trick is to add the exfoliants and stir them in the soap until the temperature is around 125-130F. At that temperature, the soap is cool and thick enough to suspend the exfoliants. 🙂
The essential oil usage rate is slightly different for melt and pour! Find out how much to add to your batch with our Fragrance Calculator: https://www.brambleberry.com/Pages/Fragrance-Calculator.aspx
We also have a Pumice and Poppy Seed Melt and Pour Tutorial you may like! It’s nice and scrubby so it’s perfect for removing dirt and grime: https://www.soapqueen.com/bath-and-body-tutorials/scrubby-pumice-poppy-melt-pour-bars/
-Kelsey with Bramble Berry
Hi, when measuring the 1.7oz of essential oil, is that by weight or flowing oz and what would it equate to in ml ? 😊
The 1.7 ounces is by weight! We find that’s a bit more accurate. To get that amount, put a glass container on a scale, zero it out and measure out the essential oil. You can also do it by volume if you like. The 1.7 ounces would be about 50 mL. 🙂
Learn more about weight vs. volume here: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/a-guide-to-weight-vs-volume/
-Kelsey with Bramble Berry
Is there a difference between using 99% rubbing alcohol and 91% rubbing alcohol to prevent soda ash? I’ve seen some recipes call for one and some recipes call for the other, and I want to be sure I’m using the right one. Thanks!
Hi Becky!
The percentage in the isopropyl alcohol refers to how much alcohol is in the mix. So, 91% means 91% alcohol and the rest is water. We have found that the 99% isopropyl alcohol is more effective against soda ash. The alcohol creates a barrier on top of the soap that protects it. I would recommend using that for the top of your soap. 🙂
Read more about 99% isopropyl alcohol here: https://www.soapqueen.com/bramble-berry-news/sunday-night-spotlight-99-isopropyl-alcohol/
This post has more tips on preventing soda ash: http://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/explaining-and-preventing-soda-ash/
-Kelsey with Bramble Berry
Is it really 8 tablespoons of walnut shells? My soap batter looks really dark. And with 5 tablespoons of pumice seems like a whole lot of exfoliants.
Wallis
That is correct! We wanted these bars to be super scrubby so they remove grease and dirt from working hands. If you want the bars a bit less exfoliating, you can add less of the walnut shells and pumice. They will feel nice either way! 🙂
-Kelsey with Bramble Berry
Could I use more pumice instead of walnut shells? My son has tree nut allergies, so I have to avoid them. Any other exfoliating suggestions?
Hi Jennifer!
You can use more pumice if you like! Pumice does accelerate trace, so keep in mind the soap will thicken more quickly. There are also several other exfoliant options you can add to the soap, including coffee grounds and jojoba beads. 🙂
Learn more about exfoliants here: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/all-about-exfoliants/
-Kelsey with Bramble Berry
What about adding raspberry seeds instead of pumice? I have some of that on hand.
We haven’t tried those in this recipe, but I think that will work just fine. They are larger grained than the pumice, so they will offer more exfoliation. You may want to make a small test batch to see what you think.
-Kelsey with Bramble Berry
Any thoughts on using Grapefruit EO, Mandarin Orange EO or Energy FO? I don’t have any 10x Orange EO but I have all the other ingredients either on hand or already en route to me and I’d love to give this soap a try next week. I feel like the Energy FO fades as well as the Grapefruit EO in cold processed soap so curious your recommendations.
Hi Kimberly, from my personal experience, none of the EOs will stick (even 10x Orange fades), but Energy FO sticks very good. The only thing is you must use the strong amount in the fragrance calculator, otherwise it won’t be strong enough. And you can also use something completely different. 🙂
I mean none of the EOs you listed will stick in CP. Some others will. For example, lemongrass EO is wonderful and it sticks. HTH
Thanks so much, I can’t wait to give this soap a try!
Hi Kimberly!
Any of those would work well! Citrus essential oils, like mandarin and grapefruit, do fade in cold process soap. The reason 10X orange sticks is because it’s super concentrated. To help anchor them, we recommend pairing them with a deeper scent like Amber Fragrance Oil. Get more tips for preventing scent fading in this post: https://www.soapqueen.com/bath-and-body-tutorials/tips-and-tricks/how-to-prevent-scent-fading-in-soap/
You can use Energy Fragrance Oil on its own! We’ve found it lasts really nicely in soap. If you want it a bit stronger, you can use the strongest recommendation on our Fragrance Calculator. 🙂
Fragrance Calculator: http://www.brambleberry.com/Pages/Fragrance-Calculator.aspx
Energy Fragrance Oil: https://www.brambleberry.com/Energy-Fragrance-Oil-P3861.aspx
-Kelsey with Bramble Berry
Thanks Kelsey! Also, thanks for sharing the link on scent fading, I hadn’t seen that before so I’ll check it out.
You’re welcome Kimberly! 🙂
Hi, I love the look of this soap but am a little confused about the ingredients -in step TWO you mentioned sunflower seed oil but at the beginning of recipe there is no mention of this in ingredients list. Help! 🙂
Hi Sheryl!
Not sure how that sunflower seed oil got in there! There is no sunflower seed oil in the recipe; I have updated the post 🙂
-Amanda with Bramble Berry
I did coffee grounds and walnut shell before. Very scrubby.
Also, in the recipe list of ingredients you say 1.7 oz Orange EO, but in the post it says 2 oz. Which is it? 🙂
Whoops, that should be 1.7 ounces! Thanks for catching that Martina. I updated the post. 🙂
-Kelsey with Bramble Berry