Full instructions for how to make lavender soap from scratch using essential oil and a natural purple soap colorant. Includes tips on using lavender-infused oil, lavender tea, and lavender flower decorations in making any lavender soap recipe.
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Lavender is a beautifully scented flower that’s also great for the skin. It can help clear acne and calm eczema, and lavender essential oil is even known for helping speed up the healing of wounds and burns. Over the years, I’ve created and shared recipes for various types of lavender soap. Some of them include a blend of essential oils, while others have added exfoliants, flowers, or natural soap colorants. The lavender soap recipe I share in this piece is, by comparison, pure and simple. It’s a single beautiful color and uses just a single fragrance – lavender essential oil. I show how to make it with common soapmaking oils and a natural purple soap colorant called alkanet.
There are many ways to make lavender soap, though. Generally, it’s accepted as soap that is scented like lavender. Sometimes that scent is natural, and sometimes synthetic perfumes are used. Other ways to make lavender soap include using homemade lavender-infused oil or lavender flower tea and decorating it with lavender flowers. I’ll go over each of these before we head into making this natural lavender soap recipe.
New to Making Soap?
If you’re new to making handmade soap, I recommend that you enroll in my natural soapmaking for beginners online course and go through the four-part soapmaking series below. It gives a good introduction to what to expect from ingredients, equipment, recipes, and how to combine everything together to make soap. It’s especially important to be careful when handling lye, and part two will tell you what to expect and how to prepare yourself.
- Natural Soapmaking Ingredients
- Soapmaking Equipment & Safety
- Beginner Soap Recipes
- How to Make Cold Process Soap
Lavender Essential Oil for Soapmaking
Lavender soap is generally understood to be a soap that smells like lavender. The real deal is always made with lavender essential oil, which are the volatile oils extracted from lavender flowers. It’s deeply fragrant and has more beneficial properties to the mind and body than I can list here. You can even grow English lavender to use in soap and skincare recipes; however, making essential oil is a whole other ballgame. It needs to be extracted with a steam distiller, and you’ll need about three pounds (1.36 kg) of lavender flowers to create just 15 ml of essential oil. That’s why most soapmakers buy essential oil.
When sourcing lavender oil for soap recipes, also be aware that there are two main types of essential oil. Lavender flower oil labeled Lavandula angustifolia (English lavender) flower oil is the more common and the type I recommend. The second is distilled from a similar plant called Lavandula latifolia and is more commonly known as lavender spike oil. It smells like lavender but has a touch of camphor and herbaceousness to it.
How much Lavender Essential Oil to Use
The below homemade lavender soap recipe has an amount of essential oil already provided, and the amount is a moderate one at just 3% of the recipe. Even though you’ll see other recipes include more, it’s best to stick to that essential oil usage rate until you’re able to work out the specifics of the product you’re using. That’s because not all essential oils are the same, and the levels of allergens can vary from manufacturer to manufacturer. It’s a bit of math and finding the right documentation for the specific essential oil you use. Sometimes it’s listed in a general PDF for all the essential oils a company manufactures. Sometimes it’s in a separate allergens declaration document.
The amount you use in soap is dictated by the levels of these 26 natural substances found in essential oils. That’s because if you include too much of them, your soap can cause allergic reactions in some people. The current main allergens to be vigilant of in lavender essential oil are geraniol, limonene, and linalool. The European Union is currently planning to add another 56 substances to this list, so, at least in Europe, the legal usage rate for lavender essential oil in soap recipes may change.
Lavender-Infused Oil in Soap Recipes
There’s another type of lavender oil that you can use in soapmaking, too, but it’s not an essential oil. Homemade lavender oil is liquid oil infused with lavender flowers, and though it won’t scent your soap, it can be a way for you to include homegrown lavender in your soap recipes. To use it, replace an oil called for in the recipe with the same oil that you’ve infused with lavender. For example, you could replace all of the olive oil in a soap recipe with lavender-infused olive oil. This castile soap recipe is made with 100% olive oil, so you could replace all of it with lavender-infused oil if you wish.
Lavender Tea in Soapmaking
Another way to use lavender in soap recipes is to substitute the water amount called for with lavender tea. It doesn’t add scent or any real properties, but again, it can add a special-to-you element to your soap recipe. It can also tint your soap a light beige, which is a nice effect. To make lavender tea for soap recipes, heat a bit more distilled water than is called for in the recipe to scalding. About 5% extra is fine. For every cup (237 ml) of water, add one teaspoon of dried lavender buds or two teaspoons of fresh. Leave to steep until the liquid is room temperature, then strain the lavender from the water, and measure the water for the amount called for in the recipe. Make the lye solution with the lavender tea as usual.
Alkanet Soap Recipe
Aside from the subtle color that lavender tea may give to your soap, lavender in itself won’t naturally color soap recipes. Especially not blue or purple. You can, of course, leave the soap its natural creamy color, but it’s fun to match the color of the soap with the scent. I’ll show you to do this later on using alkanet Alkanna tinctoria, a natural purple soap colorant. It begins with infusing the roots in liquid oil and then using that oil in the soap recipe. I recommend that at least 30% of the oils in an alkanet soap recipe are infused with alkanet. This recipe includes fifty percent, which gives a really deep and lovely color. The infused oil is also about six months old, so the color is more intense. With alkanet, you can get various shades of earthy purple, from quite light to very dark.
Alkanet is a common dye plant that is mainly wild harvested in south-eastern Europe, India, and Pakistan. Many soapmaking suppliers stock it, and it comes as chips of dried roots. There’s a lot of color potential in the smallest amount! I highly recommend that you buy alkanet from a trusted soap ingredient supplier, though. A lot of online sellers label a similar plant, ratanjot Onosma echioides as alkanet. It looks similar but will not give you a lovely purple color.
Naturally Coloring Soap Purple
Gromwell root Lithospermum erythrorhizon is another excellent natural soap colorant and is used in the same way as alkanet. Brazillian purple clay is popular, too, though it gives an even earthier purple color, as most clay soap colorants do. Infusing whole cannabis plants in a carrier oil and using it in soapmaking can also give a light purple color, though I’ve not tried this. Mixing indigo and madder may also give a lavender-like hue.
Ultramarine purple mineral powder is also popular in the soapmaking community for its stable and vibrant color. It’s not considered natural but rather a nature-identical mineral pigment. The purple it gives is much more of a conventional purple, though. Clean and bright and quite lovely in its own right. Though I don’t use mineral pigments in my commercial soap anymore, I don’t have a big problem with them like other natural soapmakers do. I used half a teaspoon of mineral powder per 1 lb (454 g) soap batch to create the color of the above soap.
Using Lavender Flowers in Soap
If there’s one way to communicate lavender soap immediately, it’s decorating the bars with lavender buds or flowers. There’s just one major issue with using them in soap: they have a tendency to turn brown wherever they touch the soap. Mix them into your soap batter, and they will definitely turn brown. Sprinkle them on top, and they’ll probably turn brown. And if you’ve ever had mice in the house and seen what they leave behind them, you’ll realize why mixing lavender buds into soap is a bad idea. The connotation between mouse droppings and your lovingly-made product is not a good one!
There are two tricks to prevent lavender from turning brown in your soap, though. The more lavender buds that don’t touch the soap or only minimally touch, the less browning you’ll see. The first one is using dried lavender buds still connected to the flower stalk. If you lightly press them into your soap about five minutes after you pour it, you can get away with just the smallest amount of browning. Make sure that only the bottom edge is actually touching the soap, as shown in the photo above. It also helps to use darker lavender varieties, such as ‘Hidcote.’ They’re so deeply colored that you don’t notice as much color changing, and they stay beautiful for months on end. All the more reason to grow lavender at home.
Stick Lavender on Soap with Rubbing Alcohol
The other method to stop lavender from turning brown on soap is even more clever. Pour the soap batter into the soap molds and allow it to sit for 24-48 hours. Pop the soap out of the molds, and cut them into bars, if applicable. Next, spray the tops with rubbing alcohol, sprinkle lavender buds on top, and spray them again. As the alcohol evaporates, the lavender will stick to the soap. Although, over time, lavender can naturally brown, it will take weeks or months before you see it happening with this method.
More Lavender Ideas and Recipes
- How to Make Lavender Bath Bombs
- Lavender & Honey Cookie Recipe (so good!)
- Lavender Body Balm Recipe
- Blueberry & Lavender Jam Recipe
Lavender Soap Recipe
- Stainless steel pan for melting the solid oils
- Rubber gloves
- Mason jars
Add after Trace
- 3 tsp Lavender essential oil 13.6g / 0.48 oz
- Lavender flowers (optional)
Make the alkanet-infused oil
- At least one month before making soap, mix the alkanet root with the olive oil in a mason jar and leave it in a dark but warm place to infuse. Shake the jar every couple of days. You'll get a good extraction of color after a month, but if you can wait for longer, the color will be much deeper. Up to a year for good deep color! Keep an eye on the best-by date of the olive oil if you plan on a longer infusion period, though.
- Alternatively, and for a quicker infusion, measure the alkanet and olive oil into a mason jar and place it in a slow cooker set on a tea towel. Fill the slow cooker up to the level of the oil in the jar, and heat on low for eight to twelve hours or overnight. Then turn it off, remove the jar from the water, and allow the oil inside to cool to room temperature. Strain the oil through a cheesecloth. Make sure to squeeze the alkanet in the cheesecloth to get every last drop.
- The dark purple soap color you see in this soap recipe's images is from oil that was double-infused. To replicate this, infuse the oil in a warm but dim place for three months. After then, strain the oil through a cheesecloth and discard the alkanet pieces. Add fresh alkanet root to the oil and let it infuse for another three months before straining and using it to make soap.
- Measure the amount of olive oil needed for the soap recipe. You may have a little leftover that you can save for another batch.
- Get everything prepared and measured before starting to make soap. Get the equipment set out and measure out all the ingredients, including the distilled water in the heat-proof jug, sodium hydroxide into a jar, and solid oils into the pan.You should also be wearing closed-toe shoes, a long sleeve shirt, hair pulled back, and wearing eye protection, and rubber/latex/vinyl gloves.
Mix the Lye Solution
- Work in an airy place, such as near an open window, and pour the sodium hydroxide into the water and stir well. There will be heat and steam, so be careful. Try not to breathe it in. Leave the jug of lye solution to cool in the kitchen sink shallowly filled with cold water.
Melt the Solid oils
- Place the pan of oils on low heat and stir and break up the oils to speed the melting time up. When there are just a few small pieces that are unmelted, take the pan off the heat and continue stirring on the side.
- When fully melted, pour the liquid oils into the pan: the alkanet-infused olive oil and the castor oil. Save the essential oil for later. One tip for reducing air bubbles in your final soap bars is to pour the liquid oils against a spatula or immersion blender placed in the pan. It helps the liquid oils to flow in rather than splash in. Air bubbles aren't necessarily bad, just something that soapmakers try to avoid for aesthetic reasons.
Taking the temperature
- When making this small soap recipe, aim to cool both the oils and lye solution to around 120°F (49°C). They don't need to be bang on but should be around that mark. An infrared thermometer makes quick work of this task but a digital meat thermometer or glass thermometer work too.
- When the temperatures are around 110°F (43°C), pour the lye solution into the pan of oils through a sieve. It will catch any bits of undissolved lye. You could also pour the lye through the sieve and against a spatula or immersion blender to again reduce the chance of air bubbles forming in your soap. This is optional, though.
- Next, dip the stick blender into the pan and press it to the bottom of the pan. With it turned off, stir the mixture, keeping the head of the immersion blender against the bottom. Next, bring it to the center of the pan, still pressing down, and blitz it for just a couple of seconds. Turn it off and stir the soap batter, using the blender as a spoon. The color of the soap batter can be anything from blue to gray to purple at this point.
- Repeat until the mixture thickens up to a light Trace. This is when the batter leaves a distinguishable trail on the surface. The consistency will be like thin custard. The batter may also look gray or blue right now, and that is completely normal.
Essential oils & molding
- Now, at light trace, pour in the essential oil. Stir it in quickly but thoroughly. You will notice the soap getting thicker as time goes on, and you'll probably be at medium trace now. It will be more like pudding.
- When the essential oil is completely mixed in, pour the batter into the molds, using that spatula to get every last bit of soap. It should fill up the 1-lb loaf mold well but have a heaping top. That's fine, and what I've done here is create swirls on top with a skewer. Just use small circular motions up and down the soap. This is optional though, and you can use whatever texture or non-texture you'd like.
- Another optional step is decorating the tops of the bars with lavender flower heads. I've only lightly pressed them in, being mindful that the buds will turn brown anywhere it touches the soap. I've placed them so that one flower head will be at the top of each bar of soap.
Cure the Lavender Soap
- Once the soap is in the mold, it helps to force the soap into gel phase. This is a period of prolonged but gentle heat that can deepen the color of the soap. It's always a good idea to do with alkanet soap recipes. There are two main ways to go about this, with the first being to wrap the soap mold up in a towel, protecting the top surface of the soap with cling film, and leave it overnight. The second way is to oven process it.
- Oven processing is very easy. Heat the oven to 170°F (77°C) and place the soap inside. I tend to place the soap mold on a square of baking paper or cardboard. Turn the oven off, close the oven door, and leave the soap in for twelve hours or overnight. Take the soap out afterward and leave it on the counter for another day.
- After two full days have passed, saponification is mostly complete, and you can pop the soap out of the mold(s). Cut it into bars with a sharp knife, if using a loaf mold, and cure the soap for four weeks before using it. The purple color will fully develop during this time, and depending on the strength of the alkanet and the length of time it was infused into the olive oil, the bars will be light to dark purple.
- To cure the soap, place the bars in an airy but dim place with plenty of air flow. Leave them there, undisturbed, for at least four weeks before using it. You should also store handmade lavender soap in the open in a dim and airy place. Doing this helps keep the soap dry and in good condition for years.