Citric acid and baking soda (aka sodium bicarbonate) are the two main ingredients in bath bombs. That combination creates the fun fizzy reaction when the bath bomb is introduced to water. Additional ingredients can be added, such as oils, fragrance, color, glitter, and more. Then the mixture is molded into fun shapes.

But, at the core, bath bombs are baking soda and citric acid. The most common bath bomb recipe is 2 parts baking soda to 1 part citric acid. Citric acid is a mild preservative that’s often used in canning and other applications like candy making. It can be a little tricky to find in stores, which is why some recipes call for substitutions. So, can you make bath bombs without citric acid?

In the Soap Queen TV video above, three experiments are conducted to see how bath bombs fizz without citric acid. The ingredients tested are lemon juice, cream of tartar, and cornstarch. Do they create fizz in the tub? The combination of lemon juice and baking soda created very little fizz. Cream of tartar bath bombs created a little more fizz, but not much. Cornstarch bath bombs had no fizz, and created a gloppy texture in the water.

The combination of citric acid and baking soda produce the best, most fizzy bath bomb. Head over to the Bath Bomb Questions and Answers post for more tips and tricks. Can’t find your answer there? Be sure to search the comments; with more than 400 comments and counting, your question may have already been answered! 😉 The “recipes” for the bath bombs tested in the video are below, although we don’t really recommend them.

Lemon Juice Bath Bomb:
1 cup baking soda
Lemon juice (until moldable texture)

Cream of Tartar Bath Bomb:
1 cup baking soda
1/2 cup cream of tartar
Witch hazel (until moldable texture)

Cornstarch Bath Bomb:
1 cup baking soda
1/2 cup cornstarch
Witch hazel (until moldable texture)

If you’d like a variety of tried-and-true bath bomb recipes that include citric acid and have plenty of fizz, check out the Bath Bomb category page.