In this book, the focus is on coloring soap bases with purely natural colorants, specifically botanical powders and clays that come from the earth, along with herbal infusions, which are highlighted in the next section. Although micas and oxides are popular soap colorants enjoyed by many crafters, because of their synthetic components, they won’t be covered here.
When working with natural colorants, I’ve found that a gentle infusing time, usually for around 30 minutes after the soap starts melting, followed by straining the soap with a fine-mesh sieve, helps to bring out their colors while reducing the amount of speckling that is sometimes associated with them. Although you can melt soap base in a microwave, and I sometimes do that myself, I find the results are more rewarding when time is taken to gently heat the soap using the double-boiler method so the colors have time to truly develop. As a bonus, you don’t have to worry about overheated soap, which can cause texture and lathering problems.
Another excellent way to avoid speckling is to dilute natural colorants with two to three times as much alcohol before stirring them into melted soap base. You may discover that a few colorants, such as jagua powder, won’t dissolve well in alcohol. In that case, you can use glycerin instead.
If you’ve made a batch of soap where a colorant’s speckling is especially noticeable and it doesn’t appeal to you, a trick to fix that is to use a vegetable peeler to shave off the speckled layer and discard it. Chop up the remaining soap, melt it down and pour it into the molds again. After unmolding the second time, you should find it now has a much smoother look.
The photos on the following pages showcase natural colorants and the usage rates used to create the colors shown. Colorants added to clear base will be strong and vivid, so you don’t need very much. However, white soap base contains titanium dioxide as a whitener, which causes botanicals and clays to turn shades of pastels, even when a higher amount of colorant is used.
Because they’re sourced from nature, natural colorants can vary somewhat in strength and color depending on how they’re grown, harvested and processed. For this reason, keep in mind that the photos shown will give a reasonable idea of what color you should expect when using a colorant, but you may find slight differences in practice. Feel free to adjust the colorant amount up or down (if needed) to better suit your product.
Blue & Purple Colorants
Alkanet Root Powder (Alkanna tinctoria)–A natural dye plant; speckles easily. For a clear deep purple, use around 1⁄4 teaspoon per 16 ounces (454 g) of clear soap base. For a medium purple gray, use 1⁄4 to 1⁄2 teaspoon per 16 ounces (454 g) of white soap base.
Cambrian Blue Clay–Rich in nutrients and algae, gentle for all skin types. Often used in higher amounts than most other clays, to better see the color. For a muted sky blue, use around 1⁄2 teaspoon per 16 ounces (454 g) of clear soap base. For a soft blue-gray, use 2 to 3 teaspoons per 16 ounces (454 g) of white soap base.
Gromwell Root Powder (Lithospermum officinal)–Similar to alkanet root; speckles easily. For a dark purple, use around 1⁄4 teaspoon per 16 ounces (454 g) of clear soap base. For a medium purple with brown undertones, use 1⁄4 to 1⁄2 teaspoon per 16 ounces (454 g) of white soap base.
Indigo Root Powder (Indigofera tinctoria)–A treasured dye plant used for generations to turn fabric beautiful shades of blue; make sure you have a truly blue indigo powder (not green). For a clear light blue, use around 1⁄8 teaspoon per 16 ounces (454 g) of clear soap base. For a soft blue with a slight blue jean color tone, use 1⁄2 to 1 teaspoon per 16 ounces (454 g) of white soap base.
Jagua Powder (Genipa americana extract)–Sourced from the juice of jagua fruit. Traditionally used similarly to henna for nonpermanent body art. It’s expensive, but a tiny amount of jagua powder will go a long way and make many batches of beautiful blue soap. For a deep blue, use 1⁄8 to 1⁄4 teaspoon per 16 ounces (454 g) of clear soap base. For a gorgeous true blue, use 1⁄8 to 1⁄4 teaspoon per 16 ounces (454 g) of white soap base.
Purple Brazilian Clay–A gentle clay that absorbs dirt and toxins; it has a beautiful natural purple tone. For an earthy dark purple, use 1⁄4 to 1⁄2 teaspoon per 16 ounces (454 g) of clear soap base. For a soft pastel purple, use 1⁄2 to 1 teaspoon per 16 ounces (454 g) of white soap base.
Woad–Acts similarly to indigo in soap; can be difficult to source, but the true blue color is worth it. For a clear light blue, use around 1⁄8 teaspoon per 16 ounces (454 g) of clear soap base. For a soft to medium blue, use 1⁄2 to 1 teaspoon per 16 ounces (454 g) of white soap base.
More from Easy Homemade Melt & Pour Soaps:
Reprinted with permission from Easy Homemade Melt & Pour Soaps by Jan Berry, Page Street Publishing Co. 2019. Photo credit: Jan Berry