Fragrance Testing in CP Soap
Hello everyone! Do you have any questions about what happens when we test our fragrances? Specifically with fragrance testing in CP soap? Well, we actually go through this process with all of our fragrances and there are quite a few specific things we look for throughout.
To start off, when making a normal soap recipe, we recommend soaping at room temperature (72 degrees Fahrenheit). However, for fragrance testing, we soap at 100 degrees Fahrenheit. Using this temperature will give you less time to “play” with the soap, and will basically force the fragrance to show any problems it may have more quickly.
For fragrance testing, we use our free recipe for our Shea Butter Soap; a recipe that includes Olive Oil, Shea Butter, Coconut Oil, and Palm Oil.
Step 1: Determining if a fragrance sample designed by our perfumist smells good enough for us to soap test. We call this stage “Test Stripping”. We start by putting a little bit of each fragrance onto a test strip (blotter paper) and smell them. The initial smell of scent on a test strip allows us to see how strong the “top notes” of a fragrance is. Then we let the test strips sit for about half an hour, then check to see if the scent has stayed, lessened, or gotten stronger. During this stage of smelling, we are able to notice more of the middle notes and base notes of the scent. You see, at Natures Garden, we typically reject hundreds of scents each year during the test stripping alone. For scents that do make the cut, we move on to step number 2.
Step 2: Testing the fragrance in soap. Once we have made our recipe and have added the correct amount of fragrance (typically 5% fragrance per batch unless IFRA is less), there are quite a few things we look for. We look for and record if there is any acceleration. Acceleration is when a fragrance oil causes the soap to trace at a faster rate than soap without fragrance would. When a fragrance oil causes accelerated trace, a soap maker must move faster when working with the soap. This can also make it more difficult to create colored swirls in your soap.
We also look for ricing, (soap batter that looks like rice pellets). Typically soap that rices can be beat into submission with a stick blender. We look for separation (fragrance will not mix with the soap, oils keep separating from the soap).
Sometimes fragrance oil will separate out of the soap batter. Usually fragrance oil will absorb back into the soap during cure, but if the oil separation is full-blown, it may cause even cured soap to be oily.
We also look for seizing (fragrance causes the soap to set up as soon as it as added). Soapers refer to this as “Soap on a stick”. Sometimes soapers are able to beat the batter back into submission with a stick blender, and other times it is impossible. Seized soap is not ruined soap, it is just soap that is no longer pliable. If allowed to cure, seized soap can be used just like soap that you had no problems making.
While cold process soap normally should cure for about 6 weeks, we oven-process soap for our fragrance testing. Oven-processing the soap in molds for about 2 1/2 hours on a temperature of about 170 degrees Fahrenheit will help the soap to cure faster, and you will only need to let it cure for about 4 weeks. When oven-processing the soap, you may see some separation. The fragrance may rise to the top of the soap and separate, but most of the time, the soap will reabsorb the oil. Oven processing also allows us to see some discoloration (if the soap is going to discolor). Typically, if a soap shows discoloration after oven processing, it will continue to discolor more during the cure phase.
After the soaps have finished their oven-process time, they can be unmolded 24 hours later. If any of the fragrances have separated during this process, wait until they reabsorb to unmold the soap. If they never reabsorb, you will know that that fragrance has a separation problem.
There are a few other things that we look for once we have taken them from the oven. We check for if the scent of each fragrance has changed or morphed throughout the saponification process. However, always remember not to judge the scent right away. Even if it has changed throughout the saponification process, wait to judge until after it has had enough time to fully cure, as it may change back.
We also look to see if there is any fragrance burn off that occurs during saponification, meaning that the fragrance may not smell as strong anymore or the notes you noticed in the beginning no longer exist. Usually, fragrance oils will not have a major burn off problem as they contain fixatives that help to anchor the scent. However, lower flash point scents have a higher chance of some burn-off than higher flash point scents. Some soapers add clay to their soap batter to help anchor their scents. Essential oils do not contain fixatives, so if you are testing essential oils, you will have more of a chance of burn-off than you would with fragrance oils.
Another thing we check for after unmolding is for discoloration. Fragrances that contain vanillin can cause discoloration, but it is mainly with fragrances that have a content of above .5%.
Soaps for fragrance testing should sit and cure for about 4 weeks. Throughout that time period, we check to see if the scent of each fragrance sticks and stays strong throughout the whole time. Once in a while, a fragrance may come along that will not work in cold process soap and never will. Make sure to remember that if you come across a fragrance like this, it will work in hot process soaps! Once the 4 weeks has passed, we check again to see if any final discoloration or separation has happened and how well the fragrance has stuck. Make sure to check out our free class for our Fragrances Tested in Cold Process Soap. This class gives a full list of all of our fragrances that we have tested, as well as the recipe for our Shea Butter Soap that we use for testing.
Make sure to check out all the rest of our free classes and recipes as well! Keep watching for more Enlightened by Layla!