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.
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
109g/ 3.8oz Sodium hydroxide (also called Lye or Caustic Soda)
196g / 7 oz Water
Natural Soapmaking for Beginners Series
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.
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.
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.
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.