Testing Fragrances Part 2

In part 1, I discussed vanillin discolouration, but it is quite possible to have a fragrance with 0% vanillin that will still discolour your soap. Fragrances are comprised of many different components, some contain 100 or more ingredients to make up a unique scent. Any of these can affect the colour as well as other aspects of soap, which is why not all fragrances are suitable for soap making. Fragrances that are considered safe to use in soap making must be skin-safe, suitable for cosmetic use and have undergone strict testing to comply with international standards. Only source your fragrances from responsible distributors, such as Pure Nature, who can provide safety data and certification from their suppliers.

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Even if the fragrance doesn’t contain vanillin, they can still cause discolouration, as the different shades of white of these soaps show.

To create a fragrance, different essential oils, resins, as well as natural and synthetic aroma chemicals are mixed together to a unique blend. Unfortunately, in most countries, fragrances do not need to list their exact constituents, because it falls under ‘trade secret’, so we usually don’t know what exactly is in them. Certain components will change the colour of your soap, just like vanillin, but because we don’t know the exact make up of the fragrances, it is difficult to pinpoint which component causes discolouration or even to predict what a fragrance will do to the soap.

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The top soap was an early test for one of my tutorials and instead of remaining white, turned a rather bright yellow during the curing time. The fragrance contained no vanillin, yet still caused significant discolouration.

The most common discolouration from a non-vanillin component is off-white, ivory or a creamy colour, although there are other possible colours as well. Oakmoss and amber, from Candlescience, for example, can cause your soap to turn a shade of mauve.

Then, there are some fragrances or components of fragrances, which have a natural tint to them and can also discolour your soap. For example, orange essential oils range from yellow to bright orange in colour, which may cause soap to turn yellow. In general, my rule of thumb is if the fragrance is not clear, that’s a warning sign! But that doesn’t mean that all tinted fragrances discolour, just like not all clear fragrances won’t discolour. And to complicate matters further, your soap recipe, the oils you use, your soaping method and the temperature can all have an influence as well. This is why you often get conflicting reports of fragrance discolouration. The only fail-proof method is to test a fragrance using the exact recipe and method yourself, to be absolutely sure of no discolouration. However, in most cases, slight changes don’t matter that much, and for the extreme discolourations that vanillin causes, looking up the vanillin content, or reading the fragrance reviews are often a good help. Or you can go for one of the water white fragrances.

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Although not a water white fragrance, the discolouration is only subtle and doesn’t distract from the overall design.

Water white fragrances are fragrances that are clear liquids, have 0% vanillin content and cause no discolouration.  There is no standard that labels these fragrances as such, and the only way to know which fragrances are water white fragrances is usually from testing or from test results that other soapers have done for you.

Here are four Candlescience Skin-Safe fragrances that can be considered water white fragrances:

And lastly, another option is to add titanium dioxide to your soap. Titanium dioxide acts as a whitener in your soap, although it will only work on light discolourations. It won’t magically turn your brown soap into the pure white! The good thing is that you only need a tiny amount to counter the discolouration, I use a maximum of half a teaspoon in one kilo of soap. Don’t use too much or you’ll end up with the unsightly glycerin rivers. Incidentally, titanium dioxide added to micas can make the colours pop, stand out more!

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