Other Additives

Once you've begun soapmaking, you will look at an amazing number of things in a new way. In addition to herbs, there are many things that you can add to your soaps to make them unique. Standing in the kitchen while making breakfast, you'll see all kinds of things you want to try in soap. Oatmeal, honey, coffee, cocoa powder … the list goes on and on. Use your imagination and try out a few of these other additives — honey, glycerin, silk, grains, seeds, other exfoliants, and cosmetic clays. You may be pleasantly surprised by what you find.


Honey can be added to soap in small amounts. It is thought to be healing and moisturizing. Be very careful when you are making lye soap with honey as it will significantly increase the temperature of the curing soap.

In cold-process applications, forgo heavy insulation if you've used honey in your formula. Soap buds have reported over and over the “honey volcano” effect, where the soap overheats and gets a big, oozing crack down the center. Soap made with honey has even “climbed” right out of the mold. Start with 1 tablespoon (.5 ounce) of honey per pound of oils.


Glycerin is a thick, sweet, clear liquid. It is a humectant moisturizer, meaning that it attracts water from the air. It is derived from plant or animal sources. The primary source of glycerin is commercial soapmaking. Saponification produces molecules of soap and molecules of glycerin, and the glycerin is removed to make the soap harder.

The word “glycerin” is often used as an adjective to describe transparent soap. Although it is a misnomer, as all soap is glycerin soap, it has come fully into the language. You can often find soap suitable for soap-casting projects labeled as glycerin soap.

In commercial soap, the glycerin is removed to make it longer lasting. You can add extra glycerin to your lye soap formula to create a more humectant bar. Start with 1 tablespoon (.5 ounce) of glycerin per pound of oils. You can include palm kernel oil in your formula to boost the glycerin content in lye soap.


Silk is an easy-to-add protein that contributes, of course, a silky feel to your soaps. Silk is produced by silkworms that are fed on mulberry leaves. It has long been prized as a fiber for creating tough and elegant textiles. You add silk to lye soap by dissolving silk fibers into the lye solution.

You can purchase silk fibers, silk powder, and liquefied silk to add to your soap. You can even cut up silk fabric and dissolve it in the lye solution. Add silk powder and liquid silk to casting soap, liquid soap, and hand-milling projects. Follow the usage rate recommended by the supplier.


You can add various forms of grain to your soap for texture. Cornmeal makes a rough scrub. Tapioca on the surface of a bar of casting soap makes a smooth, bumpy massager. And the most famous grain used in soap, oatmeal, is as popular as ever. Finely grind the oatmeal to release the skin-soothing properties for which oatmeal is so famous. If you want the look of the whole rolled-oat grain, use it sparingly since it can have sharp edges. Many soapers use baby oatmeal because it has a softer feel.

You can make “oat milk” by making an infusion of oatmeal and hot water. Strain the resulting cloudy liquid and use it in place of the water in lye soap formulas. You can also use oat milk as the liquid you use to melt soap for hand milling.


Small seeds of all kinds have been gaining popularity as soap additives. The two most readily available are coffee beans and poppy seeds. Others include cocoa powder (which comes from seeds) and berry seeds. Don't stop, though, at what you already have in your kitchen. Explore the growing possibilities.

Adding extremely finely ground coffee to the water with the lye makes a dark brown infusion and leaves tiny specks of brown in the finished bars. More coarsely ground coffee makes a good exfoliator. To release color in an infusion to use as the liquid in a lye soap recipe, the easiest thing to do is use cold strong brewed coffee. You can also use instant coffee.

Poppy seeds are great for a visual accent and because they are relatively round they're not too hard on skin. Cocoa powder comes from seeds as well. You can use it to enhance a recipe that contains cocoa butter and chocolate fragrance oil. You can also just use it as a finely textured colorant.

Berry seeds are a fairly new entrant into the exfoliant lineup. You can buy raspberry and strawberry seeds at soap supply companies.

Resins are used mainly in essential oil or liquid form. They act as scent fixatives and hardeners. Powdered benzoin resin acts as a binder for fleeting citrus oils. Use it with caution, as it can cause a reaction in some people. Rosin, like the kind used by ballet dancers, can be dissolved into the essential oils to add hardness and attractive speckles. Try ¼ teaspoon benzoin powder per pound of oils.

Other Exfoliants

Other exfoliants include sand, pumice, vanilla bean powder, and bamboo powder. If you really want to exfoliate, sand and pumice are the way to go. Always remember that rough exfoliants like these are to be used on feet and very dirty hands only. Be sure to clean any sand you collect yourself. Only buy pumice that is intended for cosmetic use.

Bamboo powder is growing in popularity as a gentle and thorough exfoliator. You can use it in much the same way you do clays in your soap recipes (as the next section describes). As with any exfoliator, less is usually more. Start with ¼ teaspoon bamboo powder per pound of oils.

Cosmetic Clays

Kaolin, bentonite, rhassoul, and other kinds of cosmetic clays are put to good use in soapmaking. Clays are known in cosmetic applications as a drying agent for oily skin. In soap, you can also use them as a coloring agent.

Adding a cosmetic clay to a soap formula can help create a good bar for oily skin. You can add clay at a light trace in cold- and hot-process soap recipes. Blend the clay into a little bit of soap batter, then return the mixture to the rest of the mass, and blend in well. In hand milling, add the clay to the melting soap mass. For casting soap, add it when the soap is quite cool, as it will sink.

While the following table is not a comprehensive look at cosmetic clays, it will give you an idea of what is available.

Kinds of Cosmetic Clay





Fine, grayish-white powder


Green clay

Fine, green powder



Medium-fine, whitish gray powder



Powder or lumps you have to grind yourself


Rose clay

Medium-fine, light red powder


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