Simple Lavender Soap Recipe + ways to make and customize lavender soap

Recipe and instructions for how to make natural lavender soap. Includes tips on using lavender flowers, natural purple colorants, & light exfoliants

Over the years I’ve created and shared recipes for various types of lavender soap. Some of them include a blend of essential oils, others have added exfoliants, flowers, or natural colors. The lavender soap recipe I share in this piece is pure and simple but can be customized if you’d like to add more flair.

That’s the beauty of making your own natural soap. Once you have the basic principles and technique down, you can make as simple and as complex soap as you’d wish. Keep this in mind when you’re making this soap recipe. Stick to the basic ingredients or feel free to use the tips below to add additional natural ingredients.

Natural Soap Making for Beginners

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

If you’re new to making handmade soap, you should check out my four-part series on natural soap making. 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 2 below will tell you what to expect. Lye isn’t something to be scared about using but you should know how to handle it safely.

History of Lavender Soap

There’s no clear reference to say how and when soap was invented. As far as historians can tell, there were various methods of making crude soap-like substances from both the middle east and china. The earliest account is of a recipe written on a clay tablet from Babylon in 2800BC. It used “water, alkali, and cassia oil”. These first soaps were probably unscented since we first hear of fragranced toilet soap in the 9th century.

The production of fragranced soap was first recorded in the 9th century by Muhammad ibn Zakariya al-Razi of Persia. A celebrated alchemist, philosopher, and considered the greatest physician of the Muslim world, al-Razi left in his legacy the first soap making recipes. Though I can’t find a reference, I strongly suspect that lavender had a part to play in scenting these very first bars.

Soap making in the middle east continues with soap factories in Syria around the same time. This Aleppo soap was imported into Europe and was then adapted there to make Castile soap — soap made with olive oil. Though Aleppo soap is traditionally unscented, it’s probable that scented soap was introduced to Europe at the same time.

Types of Lavender essential oil

Lavender soap is generally understood to be soap that smells like lavender. The real deal is always made with lavender essential oil, the distilled oil from lavender flowers. It’s deeply fragrant and has more beneficial properties to mind and body than I can list here. If you’d like to learn more about the benefits and history of lavender oil, how it’s extracted, and how to grow lavender, I have an in-depth piece that you can read here.

When sourcing your own lavender oil for recipes be aware that there are two main types of essential oil. Lavender flower oil, labeled Lavandula angustifolia (Lavender) flower oil, is the more common and it has a density of 0.885 g/ml. The second type is distilled from a similar plant called Lavandula latifolia and has a density of 0.905g/ml. It’s more commonly known as Lavender Spike oil. The measurements come into play when you’re working out how much to use in your recipes.

How much lavender essential oil to use

In wash-off skin products like soap, you should use a maximum of 3% lavender essential oil by weight. This guideline was set down by the European Union and is there to protect us against skin reactions. Lavender essential oil, like all essential oils, is not ‘pure lavender’. It’s a complex mixture of natural phytochemicals including linalool and linalyl acetate. Some people can have severe reactions to these components which is why you shouldn’t exceed this a 3% usage.

For a 1 lb (454g) batch, like the one I share below, you should use no more than 13.62g of lavender essential oil. Lavender flower oil has a density of 0.885g/ml so that works out to 15.39 ml of essential oil for a one-pound batch, or about 3 teaspoons (3.12 tsp to be exact).

Lavender spike oil on the other hand has a different density of 0.905g/ml. That means that for a 1 lb recipe you’d need 15.05ml or 3.05 tsp. It’s not a huge difference for small batches which is why I feel comfortable recommending using teaspoons or either type of lavender oil for this recipe.

If you make a whopping big batch of this though, say a 7200g (15.87lb) batch then the difference between the two is clearer.  You’d use 48 tsp of lavender flower oil or 49.5 tsp of lavender spike oil. More information on calculating essential oil amounts for soap recipes.

Naturally coloring soap purple

The natural color of soap is first dependent on the main soaping oils. Extra virgin olive oil will give you a greenish tinted soap which is why a lot of soap makers will use lighter-colored Pomace olive oil. That way they can have more control over tinting soap to the desired color. Just remember that the color of your main soaping oils will affect the final color of your soap. This is regardless of whether you use additional colorants or now.

For a traditional lavender soap recipe you wouldn’t tint the soap at all. The natural color of olive oil soap is understated and beautiful in its simplicity. If you’d like to match the lavender scent of your soap to a color there are various ingredients you can use.

Alkanet, Ultramarine violet, and Gromwell root all come to mind. Alkanet and gromwell are plant roots that you can use to either infuse some or all of your soaping oils with. You can also add the powder directly to soap but it may give your soap a gritty feeling.

Ultramarine violet is a nature-identical mineral powder that’s probably the easiest of the three to use. There is discussion over whether it can be considered ‘Natural’ since it’s recreated in a controlled environment. I have a hard time working out why folks are so up at arms over it. After all, the lye that is used in all-natural soap recipes is made in a controlled environment too. See even more ingredients that can be used to naturally color soap.

Using lavender flowers in soap

There’s one major issue in using lavender flowers and buds in soap — they have a tendency to turn brown. Mix them into your soap before it’s hardened and saponified and they will definitely turn brown. Sprinkle them on top and they’ll probably brown. There are two tricks to stopping this from happening though.

First of all, lightly press lavender stems into your soap about five minutes after you pour it. Make sure that only the bottom edge is actually touching the soap as shown in the photo above. Make sure that you don’t insulate the bars either since heat will brown them.

The other method to stop lavender from turning brown on soap is even more clever. Allow your bars to fully saponify for 48 hours. Then spray the tops with alcohol, sprinkle lavender buds on top and spray them again. The alcohol will make the lavender stick.

Over time lavender will naturally brown but it will take weeks or even months. Using these tips will ensure that it’s not instant or overnight browning though.

Natural exfoliants for lavender soap

Another way that you can customize lavender soap is by adding natural exfoliants. Oatmeal, poppy seeds, and fine pumice are all great choices and add visual interest too. Each of these would generally be added at ‘Trace’. The amounts that you can use vary but this is what I’d recommend:

• Oatmeal: use up to 1 Tablespoon (5.5g) per pound of soaping oils
• Poppy seeds: use up to 1/2 tsp (1.5g) per pound of soaping oils
• Fine Pumice: use up to 1/2 tsp (3g) per pound of soaping oils. I recommend that you pre-mix it with a little oil before adding it to avoid clumping