How to Make Natural Soap with Lemongrass Essential Oil
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How to make Natural Lemongrass Soap

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Recipe and instructions for how to make natural cold-process soap with lemongrass essential oil. Includes a full DIY video explaining each step at the end

This simple recipe for handmade lemongrass soap requires only four main oils, natural pigment in the form of oxides, essential oil, and a few other ingredients and materials. It’s also a palm-free soap recipe so you can rest assured that the ingredients are as ethical as possible.

Making cold-process soap is quick but there is a cure time of four weeks before you can use the bars. During that curing time, the extra water from the recipe evaporates out, creating hard and long-lasting bars. The DIY tutorial for this recipe is below along with video instructions.

How to Make Natural Soap with Lemongrass Essential Oil

Lemongrass Soap Recipe

800g batch — 1.76lbs (refers to oil weight)
Makes approx. 8 bars & fits in this silicone loaf mould
Technical info: 6% superfat and using water as 25% of the oil content

Lye Water
109g/ 3.8oz Sodium hydroxide (also called Lye or Caustic Soda)
196g / 7 oz Water

Solid Oils
200g / 7oz Coconut Oil
150g / 5oz Shea Butter

Liquid Oils
400g / 14oz Olive oil (or Olive oil Pomace)
50g / 1.76oz Castor oil
1/16 tsp Yellow Iron Oxide
1/16 tsp Chromium Green Oxide

Add at Trace
8 drops Grapefruit Seed Extract
4 tsp Lemongrass Essential oil

Special Equipment needed
Digital Thermometer
Digital Kitchen Scale
Stick (Immersion) Blender

Natural Soapmaking for Beginners Series

If you’d like to learn more about making natural soap, read through my four-part free soap making series. Each part includes a thorough background on soap making ingredients, equipment, safety precautions, basic recipes, and the full process of making soap. Continue below for specific instructions for the lemongrass soap recipe.

1. Ingredients
2. Equipment & Safety
3. Basic Recipes and Formulating Your Own
4. The Soap Making Process: Make, Mould, and Cure

How to Make Natural Soap with Lemongrass Essential Oil
The soap at ‘Trace’

Step 1: Measure your Ingredients

It helps to be prepared so have all of your ingredients measured and your equipment and work space set up. Get your goggles on, latex/vinyl/rubber gloves on, tie your hair back, and make sure that you’ll be able to work undistracted. Also, measure all of your solid oils into the pan and your liquid oils into a jug.

Step 2: Mix your Coloured Oil

Pour a Tablespoon of liquid oil (olive oil) into a glass and then add in the mineral powder. Blend it with a milk frother until it’s thoroughly mixed. Set aside for now.

How to Make Natural Soap with Lemongrass Essential Oil

Step 3: Mix your Lye Solution

This is the step that you need to take the most precaution. Pour the Sodium hydroxide (lye) crystals into the water in a well ventilated space. Mix together with a stainless steel spoon until the crystals are dissolved. There will be heat and steam so be prepared. The jug will get hot on the bottom and keep your face well away from the steam. You don’t want to breathe it in. When mixed, set the jug of hot lye solution in a basin of water to cool.

How to Make Natural Soap with Lemongrass Essential Oil

Step 4: Heat your Solid Oils

On very low heat, melt your solid oils until there are just a few solid bits floating around. Take the pan off the heat and stir until the oils are melted.

Step 5: Add the Liquid Oils

Pour the liquid oil and coloured oil through a sieve and into the melted oils. The sieve stops chunks of colour from getting into the soap. Also take care to scrape the castor oil out of the jug and into your pan. It’s very sticky so your rubber spatula comes in handy.

How to Make Natural Soap with Lemongrass Essential Oil

Step 6: Take the Temperature

Take the temperature of both the oils in the pan and the lye solution. The oils should be within 100-120°F and the lye solution should be within ten degrees of the oil’s temperature but lower than 120°F. When they’re just right, pour the lye solution into the pan through the sieve.

Step 7: Bring to Trace

Using your stick blender, alternate pulsing and stirring until you hit ‘Trace’. This is when your soap batter thickens enough that if you lift the stick blender out, the dribbles will hang around on the surface. The video above shows my method for pulsing and stirring and also what Trace looks like. Try to keep the blender’s head on the bottom of the pan to minimize air and splattering.

Step 8: Fragrance

When Trace is met, measure in the Grapefruit seed extract and essential oil. Stir well and then pour the soap into the mould. If you don’t stir well enough the essential oil will leave streaks in your soap. Not a huge deal when it comes to function but it doesn’t look great.

Step 9: Insulate

Slide your moulded soap into a cardboard box and close it up. Cover the outside with a towel to keep the heat in. Drafts will cause the soap to cool quicker causing the end colour to not be as vibrant.

Step 10: Cutting & Curing

After 24 hours you can pop the soap out of the mould and cut it up using a kitchen knife or thin metal wire. Afterwards, space your bars out on a piece of wax paper in an airy place that’s out of direct sunlight. Leave the soap there to ‘Cure’ for four weeks before using. This time allows the water content in the soap to evaporate out. For full instructions on how to cure handmade soap head over here

When that month is up, your handmade Lemongrass Soap is ready to be used. To preserve the scent, store your bars in a sealed tub after the curing time is up.

74 Comments

  1. Can we use liquid chlorophyll for color? If so how much and at what point do you add?

    Thanks,
    Pat

    1. Liquid chlorophyll is a great option for relatively long-lasting greens. You add it directly to soap at trace and shades can range from a light green to deep forest green, depending on how much you use.

  2. Hi,
    Thank you for your willingness to teach the soap making process. I have never to make soap, but it has always been a skill that I wanted to obtain.

    I’ve been collecting the items needed to make the Lemongrass Soap Recipe. You’ve noted in your instructional videos the necessity of following your recipes completely without making substitutions of ingredients. My question is this: are the two oxide items essential for this recipe? Can the recipe succeed without these two items: Yellow Iron Oxide and Chromium Green Oxide? My search for these two items has resulted in a possible back order situation. So, I thought I’d ask about the possibility of succeeding without these two items.
    Thank you,
    Angie Mace
    North Carolina

  3. hi, I love your blog! I’m a big fan! a 10-year dream of making soap has come true!
    thank you so much!
    I wanted to know if you have any soap recipe to use for laundry detergent?
    will I put super fat in that too? or will it make my laundry oilee?
    and have you tried making soap with canola oil? that is a cheaper oil around me.
    thank you!

  4. Hi Tanya, I’m loving the soap recipes, I’ve done three so far and the first two turned out brilliantly. My third was this lemongrass recipe and it’s fine except that just as I was pouring it some yellow lumps started to form. I’ve cut the soap now and the lumps are visible. There are some small yellow spots and some larger lumps (about the diameter of a 5p but squished). Have you any idea what I might have done wrong? I followed the recipe exactly except I left out the Grapefruit seed extract and colour, and I added half a teaspoon of poppy seeds. It took me a little while to get the temperatures right. My oils had to be warmed up, and by the time I’d got them right the lye was too cold and I had to warm it, but they were right when I poured them. The soap looks fine and usable apart from the lumps, I’m just wondering how to avoid this in future. Any advice? Thank you! Kelly

    1. I suspect that you had a good medium-to-thick trace and you poured the essential oil on top and left it there for slightly too long. Meaning seconds rather than minutes! It’s happened to me before on several occasions and mixing the essential oil in quickly at a lighter trace seems to sort it out.

      1. Thank you Tanya! This makes total sense, I think I did overdo it with the hand-blitzer, I didn’t realise it had traced already, and I probably was too slow stirring in the essential oil. Very good to know this so I can avoid it in future. Thanks so much, this has been such a helpful website for me, and I love your gardening videos too! Kelly.

  5. Bonjour
    Je voudrais savoir à quelle température mélanger les huiles et ls soude pour réussir à avoir une pâte plus fluide merci

    1. Popping your question into Google Translate, I get this: “I would like to know at what temperature to mix the oils and soda to succeed in having a more fluid paste thank you.”

      Your question is about temperature and I’m assuming you mean the soaping oils and the lye solution. For small and simple batches like this, stick to soaping at temperatures from 100-120°F (38-49°C). Higher temperatures make the soap trace a lot more quickly and can lead to the soap having a dark spot in the middle if the soap doesn’t fully gel. I’d stick to as low as you can go (100°F/18°C) if possible.

  6. Hi. I have made a batch of this soap this afternoon. It came to trace pretty quickly (much faster than the other two recipes I’ve tried so far!) I didn’t colour mine as my mica powders suggest I add some polysorbate 80 to stop them dying the bathtub and skin! I’ve ordered that now for next time. This soap smells lovely (I used my lemongrass and lime fragrance oil). It’s exciting to be trying out new recipes and each time incorporating different ingredients. This is only the third batch of soap I have ever made and the second recipe of yours I have tried so far. I can’t wait for them to cure and my family can’t wait to try them either! Thanks again for the inspiration😀

    1. Hi Suzy and I’m really pleased you’re enjoying your soap making adventure :) Keep in mind that different fragrance oils can accelerate a soap recipe and can make it trace very quickly. I suspect that’s what happened with your lemongrass and lime FO. There’s often some information on acceleration from soap making suppliers that sell FO so keep an eye out for that. Also, the mineral powder in this recipe will not dye/tint the tub so no need to add anything extra. All the best, Tanya

  7. Hi! I love these videos. I am new to all of this. Can you please explain how you measure your liquids? I have the kitchen scale, and notice that the liquid ingredients have gram conversions listed which is helpfull. However, how do you measure the liquids? I’m assuming measure and empty cup, place liquid oils into the cup, measure, and subtract the difference?

    Thank you!

    1. Hi Athena, in soapmaking you measure all of your oils using a digital scale. You can measure each oil/butter into a separate container or into the same one. Digital scales have a tare function. That means that after you measure an oil into the container, you hit the tare button to reset it to zero so you can measure the next one in.

    1. Yes, you may. Micas are similar to oxides in coloring but are less natural. They’re often made with dyes, sometimes with mineral pigments, that are coated onto mica particles.

  8. Hi lovely Tanya
    Thank u for all useful tutorials, I wanna know that is there any speacial relation between amount of solid oils and liquids? How can I change amount of each solid oil n ven how exchange them with other kind of solid oils ? Is there any formula ?

    You are great <3

  9. In your opinion, does hand milling soap really make it last longer? I really like your recipes, thanks for sharing them with all of us!

    1. Hi Lorraine, I don’t think it makes soap last all that longer. What hand milling (or rebatching) soap is great for, is adding sensitive ingredients that might be damaged in hot/cold process soap making. Herbal infused oils, delicate essential oils, and some natural colorants. It’s also a good way of fixing a batch of soap that didn’t turn out the first time in some way.

  10. I love this recipe! The soap is so smooth and creamy I almost want to take a bite out of it. Haha! The scent is amazing too. Will definitely be making this a staple!

  11. Hi Tanya,

    Thanks for the lemongrass soap recipe! As a beginning soap maker I’ve learned so much from your blog and I really appreciate all that you do. I am looking to alter your recipe a bit on my next batch to make a Lemon Thyme soap by replacing some of the lemongrass essential oil with lemon and thyme oils, and also adding thyme to the recipe. My question is twofold: First, what ratio of lemongrass, lemon, and thyme essential oils should I use. Second, what is the best way to add thyme to this recipe for best flavor? Water infusion? Oil Infusion? Fresh or dried and chopped? I have fresh thyme in my garden and can do any of these things with it, I just not sure which one might add the best smell and be best and relatively quick to do?

    Thanks!

  12. Hi Tanya! im writing from Mexico, Ican´t find the Grapefruit seed extract anywhere. Is there anything else I can use instead?
    Have a good day!

    1. Just make sure that all of your soaping oils are well within their best-by dates then you can leave it out. Grapeseed extract helps soap to not go rancid but it’s more of an issue if you’re using old oils.

  13. Hi Tanya!
    After reading your entire blog these past two weeks (ha) & watching your youtube videos (which are very, very helpful), I gathered all the necessary ingredients and tried out my first batch of soap this week!
    I followed this Lemongrass recipe exactly, took my time and used pre-measured ingredients and it went AMAZINGLY. I had low expectations for myself since I often can’t even bake a cake properly ha, but I just followed all your advice and yipee! Zero issues with mixing lye (since I had mask, gloves, goggles, well-ventilated space), I hit trace pretty quickly and then put the soap mixture in the mold, and 24 hours later..out popped my soap loaf (which was nice and smooth for cutting). I am so excited, it smells so great. I am usually not a patient or pre-measuring kind of person, but with this attempt.. I just took my time (that was key!). It actually didn’t even take very long once I had my ingredients near me. I also made sure to clean everything up while still wearing my gloves. Literally, not one single issue. One *tiny* change I did do, was that I left out the colors. I wanted my first try to have as few steps as possible. Now that everything is all cleaned up and the soap is curing, I am going to try out another one of your recipes today! Thank you for a new soaping addiction :)

  14. Going to be giving this recipe a try this week but my partner is really keen to try vanilla. Could the lemongrass essential oil be swapped for vanilla scent?

    1. Yes but fragrance oil can behave differently than essential oil in soap. It can make it ‘Trace’ — harden up — quicker and vanilla fragrance can also tint the soap a light brown colour. The quantity will be about the same though. Make sure that your fragrance is safe for skin use and look for the manufacturer’s recommendations on what to expect as far as acceleration and usage.

  15. What about using green clay in place of the mineral powders? Are the mineral powders all natural? Are they simply for the color property? Thank you!

  16. Hi there,
    This is great! Thank you.
    Just a few questions please:
    1. Would it be ok to use a stainless steel bowl for the water (to add the lye to)
    2. What is the size of the stainless steel pan you use in the video (In litres please if pos)
    3. How long does it take to reach ‘trace’ with the mini blender?
    4. I know there is a window but what is the ideal temperature of the lye & oils to mix them together
    5. What is the best way to wash/clean the utensils that have been in contact with the mixture

    Many, Many thanks

    Kristina

    1. Heat proof plastic is best for the lye solution — it helps to see the level of the lye water as well as keep the contents from melting/reacting. As far as your other questions, no idea for the trace time so you’ll have to try on your own ‘mini blender’. Stick to the temperatures in the recipe and no idea on the size of the pan. Does it really matter since you already know your ingredients quantity and the volume of your own pans? The best way to clean the utensils afterwards is to keep gloves on and wipe everything down with paper towels. Dispose of the paper towels and wash your pans and utensils by hand.

      1. Just wanted to add a little bit of information that I have learned along the way working with homemade soaps. You asked about what the ideal temperature of the lye and oils to mix them together. From my experience and literature references, about 10 to 15 degrees within each other; appears to work the best. Trace timeframe question. That can depend on usage of essential oils as this can speed up trace and other reasons can simply be just the base oil you are using. Oils that have a high saturated fatty acid profile can speed trace quicker then those that are not as saturated. Since most recipes call for multiple types of oils, there really isn’t a tell sign of how quick one recipe will trace faster than another recipe. The speed of your mini blender can also affect trace time. If you are not in a hurry to use your utensils and bowls, you could let them set for a week to harden up and then wash since it will set up as soap. It is not recommended to use your utensils and/or bowls as part of food preparation once you’ve used them for soap making. Hope this information helps. Happy Soaping!

  17. Hi, I am new to soap making. I have already followed your recipe and made my 1st batch of lemongrass soap, it looked great. But I just wanna to double check with the amount of water use in your recipe. I just use a soap calculator to read your recipe and it calculated the water to be use should be 304g!

    1. The amount of water you use in soap recipes is flexible. Remember that it evaporates out of your bars completely by the end! You need at least as much water (in weight) as you have caustic soda in a recipe. I prefer using around double that amount though. The more water you use, the slower your soap will be to harden which can be good for swirling techniques and pouring large batches. The less water you use, the quicker it will firm up — you’ll also have reduced chances of soda ash.

  18. Thank you for this recipe! I recently made it and it turned out great! Could I add activated charcoal to this soap?

    1. Make the recipe again and double check all of your measurements and ingredients. Use the exact recipe with no additions or subtractions and always measure by weight with a kitchen scale. Another person had issues as you’ll see in the comments and it turned out they were using the wrong ingredient.

      Crumbly soap can sometimes be caused by using too much lye. Double check that. Lastly, it could be your soaping temperature. If the oils and lye-water are below 100F then the chances of it turning out crumbly are much higher.

      Good luck and I hope you figure out what the issue was.

  19. I tried your recipe with my 12 year old daughter to spend some quality father/daughter time. Very methodical and the outcome was with no flaws at all. Great explanation ! However, as this was our first time with this project I noticed that the shea butter leaves a stronger scent after the cold process than the lemongrass itself. Is this normal ? We have three more weeks of curing. Will this prevalent she butter scent lessen over time ? Or, it is the brand of shea butter I am using ?

    1. Hi Normand and thanks for sharing your experience! Pleased the steps were clear and you made the recipe successfully. As for the shea butter scent — I suspect that you’ve used unrefined shea butter. The more common shea is refined and doesn’t have that much of a scent. If you’d prefer more of the lemongrass scent in the future, try to find refined shea.

    1. Do you mean frationated coconut oil? If so, yes you can but the lye amount will need to be updated. Fractionated coconut oil has a different saponification value from the solid oil.

  20. Hello there!

    I attempted this soap and came up with some pretty weird results. I measured everything precisely, and followed the temperature suggestions, but I ended up with a jelly-like substance that absolutely won’t harden up. It’s like a mix between mashed potatoes and olive oil, a big gloppy jelly. Any idea what I may have done wrong? Or if I can do anything to fix it? Thank you for your time! Any suggestions would be much appreciated.

    1. Mystery solved! Just realized I’ve been using potassium hydroxide instead of sodium hydroxide. Doh! What a waste. But a good learning experience :)

      1. Yes, Potassium hydroxide is also a soaping ingredient — but for making liquid soap and in a completely different process. Good luck with your second attempt!

  21. Hello I am new to the soap making process actually never made it before. Yesterday l made the Lemon grass soap and it looks like it turned out, and the smell coming from the curing box is very nice. I do have one comment could you look at the recipe the water measurements do not add up, it calls for 10.7 oz or 196 g of water well 10.7 oz is actually 303 grams. Which number do you follow i used the 196 grams of water and it looks like it turned out

    1. Oh dear! Yes that was a typo — I always use grams and the oz amount was incorrect. THANK YOU. If anyone made the recipe with the larger amount it’s not a big deal — it will just need the full four weeks to cure (to allow the water to evaporate out)

  22. I don’t have the mineral powders but I really want to make this soap. Can they simply be omitted?

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