Why does my bath bomb have lumps, warts or bumps on the surface?

A bumpy texture on your bath bomb is usually a result of clumps in the dry ingredients or not fully mixing the fragrance oil. Baking soda in particular tends to clump together. Before adding oil, color, fragrance or other additives, break up large clumps with your hands. To remove and break up smaller clumps, pour the dry ingredients through a fine mesh sifter. This extra step gives a smooth texture. Bath bomb warts can also occur when the fizzy contains too much moisture. Usually the culprit is fragrance or essential oil so mix extra well to ensure the wet is fully incorporated into the dry.

Why is my bath bomb not fizzing very much?

I love cupcake bath bomb.If your bath bomb is not fizzing in the tub as much as you’d like, you may try increasing the amount of citric acid in your recipe. You can start with a mix of 2 parts baking soda to 1.5 parts citric acid. In addition, if you use cornstarch in your recipe, you may try decreasing the amount or eliminating it all together. Fizzing can also decrease if a large amount of oil is used. If your bath bomb comes in contact with moisture from the air or from a damp environment, the fizzing reaction can decrease. To protect it from moisture, wrap it tightly with plastic wrap.

In the video below, several special bath bomb recipes were tested without citric acid, including cornstarch, cream of tartar and lemon juice. See how they performed once added to the tub (spoiler alert – not great).

Why is my bath bomb expanding out of the mold?

If your bath bombs are expanding in the mold, this means the mixture is too wet and the fizzing reaction is happening prematurely. If you use a colorant or fragrance that contains water, this can cause the bath bomb mixture to fizz. If this happens, the bath bombs may still may fizz in the tub, although the amount of fizz may be decreased. In addition, bath bomb mixtures can fizz prematurely due to moisture in the air. For example, if you make bath fizzies on a moist and rainy day, this can cause the bath fizzies to expand in the mold.