How to evaluate fragrance oils

Now that you’re familiar with the fragrance oil evaluation terms we'll use in this article, it’s time to go over various fragrance evaluation methods. 

Every maker has a different process, but it can be helpful to keep certain things in mind when evaluating new scents. Here are a few considerations as you hone your own fragrance oil evaluation method:

1. Notice the emotional experience of the scent. How does it make you feel? Does it remind you of anything? Is it more familiar, or exotic? Two people can smell the same note profile and have completely different emotional experiences, but that’s one of the things that makes scent such an interesting artistic medium!
2. Jot down a description of what you smell. Try to be as specific as possible, but don’t stress if you don’t have words for what you’re smelling at the moment—you can always come back and refine this later. If you smell something citrusy but can’t tell if it’s lemon or bergamot, then recording the word “citrusy” is perfectly fine, for example. 
3. Review the fragrance oil description and note profile from the supplier, then compare it with your notes. This practice helps train your nose to identify specific notes. It will also help you discern the note combinations you prefer, and those you aren’t a huge fan of. 

• Smelling a fragrance oil for the first time is undoubtedly exciting, but it can often also lead to surprise—and potential confusion—if you smell the fragrance OOB.
• Top notes evaporate the quickest, so they tend to dominate the scent profile during OOB impressions. The overwhelm of top notes tends to mute middle and base notes, which can leave you with a skewed perception of the actual scent profile.
• OOB impressions are the easiest and fastest introduction to a fragrance, but they’re not necessarily indicators of the full experience a fragrance has to offer. While OOB impressions are a valuable and important part of the fragrance evaluation process, they should never be your only step in evaluating new fragrance oils. 

• You can probably guess why blotter strips are important now that you know more about OOB impressions! When you dip a blotter strip into a fragrance oil and allow it to air out, the fragrance oil components evaporate in a more gradual manner—this allows for a more balanced impression of the scent profile.
• You get a more accurate impression of fragrance oils on blotter strips because they give top, middle, and base notes time to bloom.
• Blotter strips provide a neutral medium for smelling and evaluating fragrance oils. To use blotter strips, dip the blotter strips into the bottle then let the blotter strips dry for about 10 seconds before smelling. Hold the blotter about an inch from your nose and smell to evaluate the fragrance oil. For more detailed instructions on using blotter strips to evaluate fragrance oils, check out our How to Use Fragrance Blotter Strips video. If you don’t have blotter strips on hand, cotton swabs are a good alternative in a pinch—just make sure they are made of paper and cotton because fragrance oils can degrade certain plastics.
• While blotter strip evaluations are a fast way to get a more complete picture of a fragrance oil’s scent profile, they can’t completely predict what a fragrance will smell like once it’s in a candle, soap, or other final product. 

• The cold throw evaluation is the best way to experience a fragrance as your customers would. Evaluating the cold throw of your candle mimics the shopping experience of smelling unlit candles.
• Hot throw evaluations are a preview of the candle burning experience. A scent’s character can change as the candle burns, giving you the full experience of top, middle, and base notes. Take notes on what you're smelling during different stages of the burn cycle.
• You’ll notice differences when comparing the cold and hot throw of a candle made with the same fragrance. 
  Cure time affects the strength and character of a scent, so evaluate the cold and hot throw of your candles after allowing them to cure fully.
• Different waxes can yield different impressions of the same fragrance. Natural waxes like soy often have a more robust cold throw, while paraffin waxes are known for their intense hot throw. Always evaluate fragrance oils in the wax you intend to use them in.

• The scent and character of a fragrance oil blooms and develops nuances during different stages of the soap making process. You may not be able to detect any differences between a fragrance’s blotter strip impression and the way it smells in a freshly made bar of soap, only to be surprised by the way it smells after curing. Allow soap to fully cure before assessing fragrance strength and character. You only need to wait one day for melt and pour soap to cure.
• With cold process soap making, the character and strength of a fragrance oil can change more dramatically. Cold process soap can be a harsh environment for fragrance oils—there are many variables that can affect the performance of fragrance oils, and it’s generally recommended to cure cold process soap for at least four weeks. However, most fragrance oil suppliers test their soap-safe fragrances in cold process soap to give makers a preview of what they can expect. To learn more about our method for testing fragrance oils in cold process soap, take a look at our Cold Process Soap Fragrance Testing notes.
• Note any differences in the smell of your soap before and after lathering up. Water combines with soap as you lather, then releases scent compounds throughout the air when it vaporizes. To fully understand the character of a fragrance oil in soap, evaluate it during both dry and lathered phases.