Many people make their own homemade soap with the intention of creating a more natural product, free from questionable ingredients.
However, many people also would like their soaps to have a pleasant smell. This is accomplished with the addition of either fragrance or essential oils.
Fragrance oils are designed for use in homemade skin products, like soap, and tend to remain stable during saponification and be long lasting in storage, but what about essential oils?
Do essential oils work in homemade soap? Because of the presumed low boiling point of most essential oils, it is generally accepted that they do retain beneficial properties when used in making homemade soaps; however scents will often fade, particularly those of citrus oils.
Essential oils are often rather expensive, so the last thing you want to do is waste them.
Understanding how they tend to behave when used in the soap making process will help you make your choices wisely and get the most out of each precious drop.
Do Essential Oils Hold Up Well in Homemade Soap?
This question is often debated among soap makers.
Many believe that while some essential oils do lose their scent quickly, the therapeutic properties are not affected; therefore using them in soaps is completely justified.
Some also feel that the scents experienced in the shower and the knowledge that they’re using an all-natural product is enough to warrant their use.
Others feel strongly that while essential oils may still be present in melt and pour soaps, there’s no way that essential oils, volatile by nature, can endure the heat involved with hot and cold processing techniques.
The bottom line is, unfortunately, essential oils generally will not last as long as fragrance oils in homemade soaps, but, when the soaps are used soon after creation, many benefits may still be present.
Will the Scent Last?
The answer here really depends on which essential oils you use.
Citrus oils, such as sweet orange, lime, lemon, and grapefruit, smell wonderfully fresh when first used, but their aromas are notorious for rapidly vanishing from soap.
Citrus oils may last a bit longer in melt and pour recipes because they are not subjected to the process of saponification and there’s not a long cure time to endure before you actually use the soap.
If you’ve got your heart set on a citrus scent, I’d definitely recommend using a melt and pour soap base and using the soap right away for the best results as far as fragrance is concerned.
Other essential oils, particularly those with a strong base note, like ylang-ylang and patchouli, will hold onto their scent longer than citrus oils, but eventually, the scent will fade away or change noticeably, often within weeks.
Take comfort knowing that even though the fragrance may disappear, the soap itself will last a very long time. I explain why in this article.
Do the Therapeutic Properties Last?
Believe it or not, there have apparently not been any certified tests performed on soaps made with essential oils to see if therapeutic properties are affected by the hot temperatures and harsh conditions of saponification.
However, Dr. Kevin Dunn, chemistry professor and author of Scientific Soapmaking, suggests that as long as the boiling point of an oil is higher than saponification temperatures (up to 200 degrees Fahrenheit), therapeutic properties should not be destroyed.
To back this theory up, essential oil guru Robert Tisserand states, “There is plenty of anecdotal evidence that essential oils in soap are active…in MOST instances essential oils do in fact retain their therapeutic action!”
Flash Point Vs. Boiling Point
When you purchase an essential oil or fragrance oil, especially online, you may notice that a reference to the flash point is frequently mentioned.
The flash point is the temperature that the oil can ignite and has much more to do with shipping precautions than with soap making.
As you might guess, the boiling point is the temperature at which the oil will boil, and this does weigh in the decision of which oil to use.
If an essential oil’s boiling point is low, chances are that it will be destroyed during saponification.
The problem is that the boiling point of many essential oils can be very difficult to find.
Even on Safety Data Sheets, the boiling point is often listed as “unknown.” In this regard, using essential oils in soaps is somewhat of a game of chance.
Using a base note oil in conjunction with a light, floral or citrus scent often helps to “anchor” the lighter, flighty scent in place, at least temporarily.
Adding a clay such as kaolin or bentonite often helps a scent to cling to the soap. Some soapers add arrowroot powder or even cornstarch to produce similar effects.
What Are Essential Oil Blends?
Essential oil blends are simply combinations of two or more essential oils.
You can purchase them premade, such as a thieves blend, or you can create your own combination by pairing your favorites like eucalyptus and peppermint together.
Before mixing two or more oils, it’s a good idea to ensure that you actually like their combined scent.
To do this, grab a cotton ball or perfume test strip, add one drop of each oil, and sniff. Some pairings work extremely well together, but others may not, so be sure to test first!
How Much Should I Use?
For most essential oils, you’ll want to add between 0.4 and 0.8 ounces per pound of soap once your batter has achieved a light trace.
Of course, you can cater your recipe to suit your needs, using more or less than these recommendations.
Just keep in mind that essential oils are powerful, and using too much may irritate your skin.
One tip is to use a fragrance calculator.
All you do is type in which oil you’re planning on using, answer a few questions about the product you’re making and your recipe, and you’ll be given a suggested amount of essential oil to use to achieve a light, medium, or strong fragrance.
Things to Consider
Part of the fun of soap making is customizing each batch for personal use.
Dumping in an essential oil just because you happen to have it isn’t likely to give produce desired results. Rather, think about what you hope to gain by adding an oil or a blend.
Essential oils have many beneficial properties such as being antifungal, antibacterial, calming, energizing, etc. When selecting which essential oils to add, consider what your goal is.
If you’re wanting to bring relaxing qualities, you may choose lavender, but if you’re more concerned about antimicrobial properties, you may opt to use peppermint or tea tree.
You get the idea.
The top notes of an essential oil are the scent firsts detected when you take a whiff.
They tend to be flighty and evaporate quickly. Light, refreshing, uplifting, and flowery are words used often to describe the aroma.
Popular top note essential oils include bergamot, eucalyptus, spearmint, and citrus oils, such as orange, grapefruit, lemon, and lime.
Middle notes are deeper than top notes and take longer to evaporate. In a blend, once the top note has faded, the middle note is the next scent your nose will pick up on.
They are usually described as warm, spicy, harmonizing, and relaxing and are often referred to as the heart of an aroma blend.
Chamomile, cinnamon, geranium, honeysuckle, jasmine, lavender, rosemary, rosewood, and tea tree essential oils are commonly used middle note oils in soap making.
Base notes are the slowest to evaporate, and as such, they are usually the last scent your nose detects in a blend after the other, lighter aromas have faded away.
They have an intense, deep, usually earthy scent and a grounding quality. In blends, base notes help to “fix” scents and provide staying power for the lighter notes.
Examples of base notes used in blends for soap making are cedarwood, frankincense, ginger, myrrh, patchouli, peppermint, sandalwood, and ylang-ylang.
You should know that notes don’t just apply to blends. An individual essential oil can contain features of all three notes and be quite complex in fragrance.