Making Soap Without Synthetic Fragrance Oils: Is It Possible?

Synthetic fragrance oils are often used to scent handmade soap. However, it is possible to make soap without synthetic fragrance oils by using essential oils, which are natural extracts of herbs, flowers, plants, and trees. Essential oils are created through physical extraction processes such as steam distillation, which involves heating the components until a gas is released and then condensing the gas back into a liquid. This gentle process ensures that sensitive compounds don't break down. Popular essential oils for soap-making include lavender, patchouli, litsea cubeba, and orange.

One advantage of using essential oils is that they are all-natural, so if you're aiming to make soap with all-natural ingredients, essential oils are the best choice. Additionally, essential oils are extensively tested for purity, and it's easy to recreate or intensify the aroma of fresh ingredients by using the essential oil derived from that specific plant.

However, some essential oils may be too costly for use in large volumes, and not every desired scent is available as an essential oil. For example, there is no essential oil option for vanilla due to the need for a solvent to release its aromatic compounds. In such cases, fragrance oils are often used as an alternative.

Ultimately, the choice between using essential oils, fragrance oils, or a combination of both depends on the desired outcome and personal preferences.

Natural vs synthetic scents

Natural Scents

Derived from herbs, flowers, and plants, essential oils are the most common choice for natural scents in soap making. Steam distillation is a popular extraction method, where components are heated to release a gas, which is then condensed back into a liquid, ensuring sensitive compounds don't break down.

The benefits of essential oils are extensive. For example, lavender essential oil has calming and relaxing properties and can help soothe irritated and dry skin. However, there are limitations to their use. Firstly, not everything in nature produces an essential oil, so options are limited. You won't find strawberry or vanilla essential oils, for instance. Secondly, they can be quite expensive, and their scents may not withstand the harsh environment during the initial soap-making process. Additionally, some essential oils can be skin irritants, cause photosensitivity, or be unsafe during pregnancy.

Synthetic Scents

Fragrance oils, on the other hand, are synthetic and created with a mix of aroma chemicals and natural ingredients like essential oils, extracts, and resins. Just one fragrance oil can be made up of 40-80 materials, and the possibilities for unique scents are endless.

Fragrance oils are significantly cheaper than essential oils, and their use allows for very specific, layered, and complex scents that may be challenging or impossible to achieve with essential oils alone. For example, creating a rose scent with rose essential oil would require a large volume, making it pricey, and its delicate aroma may fade during the soap-making process. With a rose fragrance oil, the scent is more likely to be potent and linger on the skin.

The choice between natural and synthetic scents ultimately depends on the soap maker's preferences, requirements, and budget. While natural scents offer therapeutic benefits and a direct connection to nature, synthetic scents provide more creative freedom and are more cost-effective. Soap makers may even choose to use a combination of both, experimenting with various options to find the perfect balance for their products.

Essential oils and their extraction process

Essential oils are natural extracts of herbs, flowers, plants, and trees. They are highly concentrated and often require large amounts of plant material to produce. The benefit of using essential oils is that we know exactly what ingredients are in the final product.

There are several methods used to extract essential oils from plants. Each method has its advantages and determines the biological and physicochemical properties of the extracted oils.

Steam Distillation

Steam distillation is the most common technique for extracting essential oils. It involves passing pressurized steam through the plant material in a closed chamber, causing the volatile compounds to evaporate. The resulting liquid is then condensed, and the essential oil naturally separates from the water.

Cold Pressing (Expression)

Cold pressing is a traditional method used for oils that degrade when exposed to heat, such as citrus fruits. This technique involves scraping or pricking the fruit peels, then pressing and rinsing the oils away with water. The water and oil are then separated. Cold-pressed oils retain natural flavors, colours, sterols, and vitamins.

Solvent Extraction

Solvent extraction uses a chemical solvent, such as ethanol or methanol, to dissolve the aromatic molecules from the plant material. The mixture then undergoes a process to separate the absolute from the solvent, leaving a solid extract at room temperature. Solvent extraction is often used for delicate plants, like Jasmine flowers, that are not suitable for steam distillation.

CO2 Extraction

CO2 extraction uses carbon dioxide as a solvent and is a highly "tunable" method. By adjusting the temperature and pressure, this process can effectively extract targeted compounds while leaving behind undesirable constituents. This technique is environmentally friendly, non-flammable, and non-hazardous.

These are just a few examples of the processes used to extract essential oils. The choice of method depends on various factors, including the type of plant, volume of biomass, intended use, and production scale.

Fragrance oils and their composition

Fragrance oils are a combination of natural ingredients and synthetic aroma chemicals. They can contain dozens of different ingredients to create complex and layered scents. They are primarily designed for their scent rather than therapeutic benefits.

Fragrance oils are made up of three types of scent notes: top, middle, and base. Top notes are the initial scents that are light and fresh, middle notes emerge after the top notes and are often floral, fruity, or spicy, and base notes are deep, long-lasting scents that give the fragrance its stability.

Fragrance oils can be natural, synthetic, or a combination of both. Natural fragrance molecules, derived from plants, fruits, and flowers, tend to have a more complex and multi-layered scent profile but can be difficult to harvest in large quantities. Synthetic molecules, on the other hand, allow for more consistency and creativity in fragrance development, and can be used to mimic natural scents or create entirely new ones.

The composition of fragrance oils can include:

• Aldehydes: Synthetic compounds known for their clean and sometimes soapy scents.
• Esters: Responsible for fruity and sweet scents, abundant in fruits like apples, strawberries, and bananas.
• Vanillin: A primary component of vanilla extract, found in the base notes of fragrances.
• Musk compounds: Create animalic and sensual scents, with synthetic musks being more commonly used due to ethical concerns.
• Terpenes: The largest group of natural fragrances, found in natural sources like citrus fruits, pine trees, and lavender.

Pros and cons of essential oils

Essential oils are highly concentrated oils extracted from plants, herbs, flowers, and trees. They are created with physical extraction processes such as steam distillation, solvent extraction, and expression. In soap making, they serve as natural alternatives to synthetic fragrance oils, offering various benefits and drawbacks.

Pros of Essential Oils:

• Natural and Plant-Based: Essential oils are derived from plants, making them a natural and vegan option for soap making.
• Customizable Scents: They allow for experimentation with different blends, enabling the creation of unique fragrances.
• Gentler on the Skin: Essential oils are softer and more gentle, reducing the likelihood of skin irritation compared to synthetic fragrance oils.
• Moisturizing: Soap bars containing essential oils are deeply moisturizing and nourishing for the skin.
• Eco-Friendly: Sustainable harvesting of essential oils helps keep soap eco-friendly and supports certain species favored by pollinators and wildlife.

Cons of Essential Oils:

• Limited Scent Options: Not all fragrances are available as essential oils, and some desired scents may require the use of fragrance oils.
• Fading Fragrance: Some essential oils may experience scent fading in soap, requiring the use of base notes to anchor the fragrance.
• Cost: Essential oils are more expensive than fragrance oils, and large quantities of plant matter are needed to create each drop.
• Discoloration: While less prone to discoloration than fragrance oils, some essential oils can still cause soap to change color or morph between colors during curing.
• Acceleration of Trace: While less likely to accelerate trace than fragrance oils, some essential oils may still cause this issue.

Pros and cons of fragrance oils

Fragrance oils are synthetically produced in a laboratory and can have numerous different components. While they are not natural, they are safe to use and, in some ways, are more sustainable than essential oils.

Pros of fragrance oils

• Available in a wide range of pre-mixed fragrances, so there is no need to know note blending.
• Available in impossible scents if you go down the essential oil route. For example, if you wanted to make strawberry-scented soaps, you would need to use fragrance oil.
• More sustainable and do not require vast quantities of plant materials to produce.
• Generally cheaper than essential oils.
• Have a broad range of scents.
• Easy to find.

Cons of fragrance oils

• May cause discolouration of your soap. Vanilla, for example, will generally turn brown.
• Can change colour or morph between colours during saponification and curing.
• Some fragrance oils accelerate trace or cause your soap batter to seize.
• Not natural, which may limit market appeal.
• Made from toxic chemicals.

Frequently asked questions