Written by Elizabeth Mika
Founder and Maker, Bramble & Bear™ Soap Co.
What gives handmade soap its scent, how fragrance use levels are determined, and how fragrance is evaluated as part of the complete soap formula.
Scent is often one of the first things we notice about a bar of soap.
In cold process soap, that scent usually comes from fragrance oils, essential oils, or a combination of aromatic materials. But choosing a scent is only the beginning.
A soapmaker also has to consider how much of that fragrance is appropriate for the product, what the supplier’s technical documentation allows, and how the fragrance behaves during soapmaking and cure.
So before we get to IFRA and fragrance limits, it helps to start with the most basic question: what actually scents the soap?
What Actually Scents Cold Process Soap?
Cold process soap is commonly scented with fragrance oils, essential oils, or a combination of aromatic materials.
The visual below compares two common sources of scent used in soap: fragrance oils and essential oils. A complete text version follows the image.
Two Sources of Scent - Text Version
Fragrance Oils — The visual shows vanilla, ocean mist, and grapefruit as examples of fragrance oils.
Essential Oils — The visual shows lavender, peppermint, and eucalyptus as examples of essential oils.
Fragrance Oils
A fragrance oil is a formulated blend of aromatic materials. Those materials may be naturally derived, manufactured, or a combination of both.
A fragrance can recreate something familiar—such as lavender, citrus, rose, or woods—or create a more complex scent that does not exist as a single plant or flower.
Essential Oils
Essential oils are aromatic materials obtained from plants, often through processes such as distillation or expression.
Lavender, peppermint, eucalyptus, cedarwood, and citrus oils are familiar examples.
Like other aromatic materials, essential oils contain naturally occurring constituents that may be subject to IFRA Standards and usage limits depending on the material and finished-product category.¹
How Fragrance Use Levels Are Determined
The International Fragrance Association, or IFRA, develops industry Standards for the safe use of fragrance materials in consumer products. Those Standards establish conditions of use and, where applicable, maximum use levels for fragrance materials.
Applicable use levels depend on the fragrance material and the type of finished product. Bar soap falls under IFRA Category 9, which includes primarily rinse-off products with body and hand exposure.²
That means the same fragrance may have a different allowable concentration in bar soap than it does in products such as body lotion, perfume, or candles, because the way people are exposed to each type of product is different.
The visual below illustrates how IFRA fragrance categories differ by product type and exposure. Bar soap is shown as Category 9. A complete text version follows the image.
How IFRA Fragrance Limits Work - Text Version
Fine Fragrance — Category 4. Leave-on product with higher exposure.
Body Lotion — Category 5A. Leave-on product with moderate exposure.
Bar Soap — Category 9. Rinse-off product with body and hand exposure.
Candles — Category 12. Home fragrance with lower exposure.
Home Fragrance — Category 10. Ambient fragrance with indirect exposure.
Main point: The same fragrance can have different allowable levels depending on the product and how it is used.
The Maximum Is Not the Recipe
The applicable IFRA maximum is a ceiling, not a target.
A soapmaker may use less depending on the fragrance, the desired scent strength, the soap formula, and how the fragrance behaves during production and cure.
Different fragrance formulations contain different aromatic materials, so their applicable use levels can differ.
In practice, a soapmaker checks the supplier’s documentation for the specific fragrance and the appropriate product category.
That preserves the important educational point without adding unnecessary negative language.
What Is an IFRA Certificate?
Fragrance suppliers commonly provide a Certificate of Conformity to the IFRA Standards for a fragrance mixture.
For bar soap, the relevant category is Category 9.
The certificate indicates that the fragrance mixture conforms to the applicable IFRA Standards for its intended use.³
For finished soap, the more precise wording is that the fragrance is used in accordance with the applicable IFRA Standards and supplier documentation.
IFRA Standards are industry standards rather than government regulations and operate alongside the laws and regulations that apply where a product is sold.
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What Happens to Fragrance During Soapmaking?
Cold process soapmaking involves saponification, followed by several weeks of cure.
Fragrance is part of that process, and different fragrance formulations can behave differently in soap. A fragrance can influence how quickly the batter thickens, how much working time the soapmaker has, the color of the finished bar, and how the scent develops during cure.
Because of this, soapmakers often test a new fragrance in a small test batch or mold before using it in full production. This helps them observe how the fragrance behaves in the formula and how the scent and appearance develop through cure.
These differences are part of why fragrance selection involves more than how a scent smells from the bottle. The fragrance also has to work well with the soap formula and the soapmaking process.
How Fragrance Can Influence Soap Color
Certain fragrance materials—especially vanillin—can cause cold process soap to deepen in color as it cures, ranging from cream and tan to brown or deeper brown tones.
Before using a fragrance in production, soapmakers can review the supplier’s product information for vanillin content, discoloration notes, and any available cold-process test results. These details can help predict how the fragrance may affect the finished bar.
Soapmakers can then plan the color palette and design around that behavior, making the fragrance-induced color part of the intended appearance rather than an unexpected result.
Fragrance therefore influences more than scent; it can also play a role in the visual design of the soap.
Fragrance Oil vs. Essential Oil: Is One Better?
Fragrance oils and essential oils are different types of aromatic materials, and each can be used in cold process soap.
Essential oils are plant-derived, but “natural” does not automatically mean unrestricted or inherently safer. They contain naturally occurring aromatic constituents that may be subject to IFRA Standards and usage limits.
Fragrance oils are formulated blends that may combine naturally derived and manufactured aromatic materials and are used within applicable IFRA limits.
For either type, the practical question is whether the fragrance is appropriate for the product, used within the applicable limits, and compatible with the finished soap formula.
From Fragrance Bottle to Finished Soap
The visual below summarizes five factors a soapmaker may consider when using a fragrance in cold process soap. A complete text version follows the image.
From Fragrance Bottle to Finished Soap - Text Version
Supplier Information — Check the fragrance supplier's technical documents.
IFRA Category — Use the correct product category and applicable level.
Formula Needs — Use the amount appropriate for the particular formula.
Soapmaking — Watch for changes in behavior or discoloration during production.
After Cure — Check how well the scent holds after the soap has cured.
Main point: The same soap base can produce different results when different fragrances are used.
What a Soapmaker Actually Has to Consider
Before a fragrance reaches a finished bar, a soapmaker may need to consider:
- the fragrance supplier’s technical documentation
- the correct IFRA category and applicable use level
- how much fragrance the particular formula actually needs
- how the fragrance behaves or discolors during soapmaking
- how well the scent holds after cure
This is one reason two soaps made from the same base formula may not contain exactly the same percentage of fragrance.
The fragrance itself can change the calculation.
Finding the Right Fragrance Level
Fragrance level is part of the overall soap formulation.
The amount used depends on the fragrance itself, the desired scent strength, how it performs through soapmaking and cure, and the applicable IFRA limit.
A higher fragrance load does not necessarily produce a more refined or longer-lasting scent. The goal is to use the amount that works best for that particular fragrance and soap formula while remaining within the applicable IFRA Standards.
What Influences Fragrance in the Finished Soap
The type of fragrance is only one part of the finished scent. The soap formula, fragrance level, soapmaking temperature, gel phase, and cure can all influence how a fragrance develops in the finished bar.
Cold process soap naturally generates heat during saponification. Some soapmakers encourage the soap to enter gel phase by insulating the mold, while others keep the soap cooler to avoid gel. Because heat can affect some aromatic materials, particularly more volatile notes, the same fragrance may develop differently depending on how the batch is processed.
The oils and butters in the soap formula can also influence the finished scent. Some base ingredients have noticeable aromas of their own, while the overall formula can affect how a fragrance performs during soapmaking and cure.
For this reason, soapmakers commonly evaluate a fragrance in the actual soap formula—often in a small test batch—before using it in full production. Supplier cold-process test results are useful, but they are based on the supplier’s test formula and may not predict exactly how the fragrance will behave in a different recipe.
The Bigger Picture
Fragrance is an integral part of cold process soap formulation rather than simply a finishing touch.
Choosing a fragrance involves more than selecting a scent that smells appealing from the bottle. A soapmaker also has to consider the supplier’s technical documentation, the applicable IFRA Standards, the fragrance level, compatibility with the soap formula, behavior during soapmaking, and how the scent and appearance develop through cure.
Small test batches can help show how a fragrance performs before it is used in full production. Factors such as the oil formula, working temperature, gel phase, discoloration, and cure can all influence the finished result.
The goal is to choose a fragrance and use level that work well with the complete soap formula while remaining within the applicable IFRA Standards.
In that sense, fragrance is part of the formulation itself: it affects not only scent, but also the way the soap is designed, tested, and produced.
Explore Bramble & Bear Cold Process Soap
Discover our collection of handmade cold process soap, thoughtfully formulated with oils, butters, and other ingredients chosen to work together in the finished bar.
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Cold Process Soap Series
What different oils and butters contribute to a finished bar.
What honey, oatmeal, clay, milk, charcoal, and other soap additives actually do.
Part 3 — Fragrance & IFRA
What scents handmade soap, how fragrance limits are determined, and why more is not always better.
Sources
1. U.S. Food & Drug Administration, Aromatherapy and Fragrances in Cosmetics. FDA explains that plant-derived or “natural” ingredients are not automatically safer simply because of their source.
2. International Fragrance Association, Guidance for the Use of the IFRA Standards. Bar soap is classified as IFRA Category 9, which covers primarily rinse-off products with body and hand exposure.
3. International Fragrance Association, Certification of Conformity with the IFRA Standards and IFRA Code of Practice. Certificates of Conformity are prepared within the fragrance supply chain; IFRA does not certify individual finished consumer products. IFRA Standards operate as an industry risk-management system alongside applicable laws and regulations.
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