Have you ever molded the perfect bath bomb only to try and move it after drying to have it crumble through your fingertips? Grrrrrrrrrrr. This can be extremely frustrating!
Powdery bath bombs typically mean that you don’t have enough wet/binding ingredients in your formula. It can be especially common if you live in a dry climate with little to no humidity.
If you add clay, oatmeal or other ingredients that absorb moisture, you might need to use more binder or wetting ingredients than usual as the clay, oatmeal, etc., can absorb moisture.
You can try a few things.
Use More Wetting Spray
Whether you use alcohol, witch hazel or water to wet your mixture, spray your bath bomb mixture a bit more than you typically do. You might be wetting it just enough to mold and hold together temporarily, but not enough to bind it all together permanently.
One tip for testing your mixture before molding is to grab some mixture and press it together in your hand tightly. Hold your hand about 12″ above your mixing bowl. Drop your hand-pressed bomb. Does it hold together or break apart? This might help you determine if you need more wetting spray.
Use Water to Bind
If you are currently using alcohol or witch hazel to spray and bind your bombs, switch to water. Water usually creates a harder bath bomb that doesn’t crumble. Alcohol evaporates so quickly, without activating enough of the mixture. Water actually activates a tiny bit of the mixture, hardening it up quickly. You can switch to using water only, or you can use a combo of alcohol + water or witch hazel + water.
Obviously, if you use too much, you’ll get warts or too much activation in your bombs.
Include Oil in Your Formula
Do you include an oil in your mixture? If not, try adding some avocado, grapeseed or other light oil. Oil can help to bind and harden your bath bombs. The oil in combination with your wetting spray can help to create a hard bomb.
Too much oil can cause a bomb that doesn’t dry. I typically add 1-2 teaspoons (5-10 grams) per cup (or 250 grams) of baking soda.
Butters can help to harden your bath bombs by solidifying quickly after molding. It literally acts as a glue, holding your ingredients together. Pick a brittle oil such as cocoa butter or kokum butter for best results. Melt it before adding to your bombs and quickly mix it in.
There isn’t a perfect solution to powdery bath bombs, but if you try a couple of the suggestions above, you’ll be able to fix your powdery bath bomb issue. The first thing to try is to switch to using water to bind your bombs. That will usually fix the issue easily.
Have you had powdery bath bombs in the past? How did you fix the problem? Please leave a comment!