Bright, beautiful, and scented with natural lemon, this lemon soap recipe makes a bar that’s perfect next to the kitchen sink. Easy enough for beginners, and I’ll walk you through every step. One of my very favorite cold process soap recipes.
Lemon Soap Recipe
Equipment
- safety equipment (goggles, gloves, mask)
Ingredients
- 4.27 ounces lye
- 9.5 ounces water
- 11 ounces olive oil
- 11 ounces coconut oil
- 6 ounces shea butter
- 2 ounces castor oil
- 2 teaspoons grated lemon zest divided
- 0.4 ounces sodium lactate
- 3 tablespoons fragrance oil or lemon essential oil optional
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Instructions
- Make the lye water. Measure out the lye and the water in separate, non-reactive containers, using a digital scale. Combine the lye and the water and stir until dissolved. The lye solution will heat up as the result of a chemical reaction. Be careful of fumes, heat, and the corrosive solution. Set the cup aside to cool in a very safe place.
- Heat the oils. Measure out the oils in separate containers and place them in a pot. Add 1 teaspoon of the lemon zest. Melt over medium low heat until fully melted and about 130-140 degrees. Remove from the heat and set aside to cool.
- Prep for blending. Check the temperature of both solutions after an hour or so. Before proceeding, they should be around 90-100 degrees. It is best if they are within ten degrees of each other. Add the sodium lactate to the cooled lye water. Before blending, have your soap mold, last teaspoon of lemon zest, and fragrance ready. Put on gloves and googles.
- Blend to trace. Pour the lye solution into the melted oils and blend with a stick blender until you reach trace. Trace is reached when the soap forms a batter and the stick blender leaves a trail when dragged across the top of the pot. Once trace is reached, add the fragrance and remaining lemon zest and stir in by hand. Immediately pour the soap batter into the mold. Place in a turned off oven or other draft-free place and allow to set for 24 hours.
- Pour into mold. Immediately pour the soap batter into the mold. Place in a turned off oven or other draft-free place and allow to set for 24 hours.
- Cure. Turn out the loaf of soap and slice into bars. Allow to bars to cure in a well-ventilated space for at least 2 weeks before using. Since this soap has a high percentage of olive oil, it will last longer if allowed to cure for 4 weeks.
Video
Notes
One of the Best Homemade Soaps
Fresh and pretty. This is a great bar of soap to keep next to the kitchen sink. It is gentle enough to be used over and over on your hands and because the lemon zest is so refreshing and beautiful to look at. You can give this as a Christmas gift or keep it for yourself.
Palm-free. This is a palm free recipe and it does have a large percentage of olive oil, which means it will seem slightly soft and sticky at first but will firm up nicely over a few weeks.
Beginner-friendly. This is not a difficult recipe and is suitable for beginners, as long as you first read up on the basics of the soapmaking process.
What You’ll Need for Lemon Cold Process Soap
Soap making is a science, in a way. You’re combining things that have specific properties and need specific amounts oof lye to turn into soap. If you would like to substitute any of the oils, you can, but with the understanding that you are now creating your own soap recipe and the lye amount might change. Here’s how to calculate it and figure out what substitutions will probably work.
- lye, aka sodium hydroxide. There is no substitute for lye in soap making. If you aren’t comfortable working with it, try a melt and pour recipe.
- olive oil
- coconut oil
- shea butter
- castor oil
- grated lemon zest (really any citrus zest will work! try substituting grapefruit zest for a grapefruit soap)
- sodium lactate (optional, for a harder bar)
- fragrance oil (optional, I like this refreshing lemon fragrance)
Nurture Soap is a great source for soap-making supplies. They carry the oils, fragrance, and molds you need for this project.
- Soap mold, either bars or a loaf style mold, I use a 10-inch silicone loaf mold
- Stick blender
- Digital scale
- Safety gear
- Old pots, cups, and dish towels
Natural Soap Tips for Each Step
Measure Ingredients In a Safe Place
Before you take out your first ingredient, make sure you have set aside enough time to do this project. You want be to be able to work distraction-free and not rush. Soap making requires time and precision. If you are rushed or distracted you will make mistakes and can hurt yourself.
Work in a well-ventilated area when you combine the water and lye: either next to a window, or outside. Make sure you have all. the ingredients and supplies you need so you aren’t leaving things unattended to grab what you need.
Put on your googles, gloves, and long sleeves.
Make Lye Water and Melt Oils
First measure out the lye and water, separately, using a digital scale. The water in soap recipes is flexible and anywhere from 8-11 ounces is fine for this recipe. It has a high percentage of olive oil, so the lower amount will help it cure faster.
Combine the lye and water by adding the lye to the water, never the other way around. To remember this, use the saying “snow floats on the lake”. This will release a lot of fumes, and the lye water will become very hot. Stir until the lye flakes dissolve, and put the cup aside someone to cool. Choose a place where it will not be disturbed. This is very important, as if the cup spills it will ruin. your kitchen surfaces, burn skin very badly, and can cause blindness. It can be fatal if someone accidentally drinks it.
While the lye water is cooling, measure out the oils. It is best practice to measure them out in separate containers and then combine them in a pot. Put one teaspoon of lemon zest in the pot with the oils. Melt them over medium low heat until fully melted and 130 degrees in temperature. Set the pot aside somewhere to cool.
Cooling, Blending, and Pouring
About an hour later, check the temperature of the lye water and the oils. You want them to be anywhere from 90 to 110 degrees before blending. It is best if they are very close together in temperature. If all is well, it’s time to start blending. If not, let them cool more or heat up the oil just a tad more if it has cooled too quickly.
The lemon zest is added in stages: first to the oils. This zest mostly gets blended into the soap and adds beautiful yellow color. The rest gets stirred in by hand to give the speckled, lemony look to the bar.
Before blending, make sure you have your goggles on to protect your eyes. Pour the lye water into the pot of melted oils and begin to blend with the stick blender. Blend with the motor on for a few minutes, then turn it off and stir by hand for a minute to avoid burning it out. You will see the lemon zest become pulverized and the oils may become more yellow in color.
Keep stick blending until the soap batter reaches trace. This occurs when the solution thickens and no longer acts as a pure liquid. If you pick up your stick blender, you will see a trail or “trace” of soap batter resting on the surface rather than sinking immediately down into it.
When trace has been reached, add in the remaining lemon zest and stir by hand. If you would like to add fragrance or color, add them at this point as well.
Immediately pour the soap batter into your mold. This recipe will fit perfectly into a 10-inch silicone mold. If you are using a different shape or size, make sure you have an extra one to catch any overflow, just in case.
This soap does not usually gel. Put in a turned-off oven or another draft-free place to allow it to cure for 1-2 days.
When you un-mold it, it is a bit softer and stickier than you may be used to because of the high olive oil content. If it’s too hard to get cleanly out of the mold, give it another day to cure.
When it’s ready, slice into bars and allow to finish curing in a well-ventilated space for a few weeks. Make sure you store the bar on a breathable soap dish, such as a soap saver, to allow it to dry fully between uses.
Customizing Your Bar
We’ve already discussed that you can’t change the oils without a doing a little math. But there a few easy swaps you can make.
- Add in dried herbs like basil or lemon balm at trace.
- Pour soap base into a bar bold instead of a loaf mold.
- Try a completely different fragrance oil.
Looking For More Soap Recipes?
- A bar of homemade bar dish soap would be lovely next to this one in the kitchen.
- The absolute bubbliest and most moisturizing shower soap is our most commonly made bar.
- And if you love adding pretty things to soap, you will love this beeswax and honey soap recipe.
- Oatmeal soap has bits of ground oats for exfoliation.
By Katie Shaw
Katie lives in Virginia with her husband, three daughters, a chocolate lab, and over thirty chickens. She loves creating simple tutorials for sourdough, bread, and soap. Her recipes, articles, and YouTube videos reach millions of people per year.