The major ingredient in bath bombs is sodium bicarbonate, sometimes known as baking soda. When mixed with water and citric acid, baking soda is classified as a “weak base,” resulting in an effervescent fizzing acid-base chemical reaction. Baking soda softens bath water and leaves skin feeling silky smooth and soft.
The second most important element in bath bombs is citric acid. When coupled with baking soda and water, it is a naturally occurring “weak acid” generated from citrus fruits that enhances the fizzing reaction.
Cornstarch is a typical “filler ingredient” used in bath bombs as a hardening agent and to increase volume. However, if you use too much cornstarch, it will limit the fizzing and overall effect of your bath bombs, so don’t use too much!
CREAM OF TARTAR AND/OR CLAYS
Bath bombs are typically hardened with clays and/or cream of tartar. We recommend white kaolin clay as an excellent hardening agent if you like to utilize clay.
SODIUM LAURYL SULFOACETATE (SLSA)
SLSA is a surfactant made from coconut and palm oil that produces sumptuous and rich foamy bubbles during the chemical reaction.
For their alleged health benefits, salts are widely used in bath bomb recipes. Epsom salt is the most often used salt, and it is said to relieve muscle pain and improve overall well-being. Because of its purifying effects, pink Himalayan salt and sea salt are frequently utilized in bath bomb recipes.
NOTE: Salts are known to attract water and can sometimes initiate the fizzing process early, thus they should only be used in limited amounts. The greatest results and smoothest surface on your finished bath bombs come from grinding coarse salts to a fine powder.
Oils are utilized to help bind the bath bomb mixture together and give moisture to the recipe. Oils have moisturizing properties that soothe and moisturise skin, and different types of oil provide additional advantages to the bath bombs, such as antioxidant and anti-aging effects. Coconut, sweet almond, avocado, grapeseed, and jojoba are the most often utilized oils.
Bath bombs containing oils should be avoided because they can make your bathtub slick!
Butters also give moisture to your bath bombs, making them feel silky and smooth on your skin. Additionally, some butters may aid in the hardening of bath bombs. Cocoa, shea, avocado, coffee, and mango butters are all popular. Bath bombs containing butters should be avoided because they can make your bathtub slick!
FRAGRANCE OILS AND ESSENTIAL OILS
Essential oils, which are sourced from plants, can add aroma as well as health benefits to your bath bombs. Fragrance oils are primarily synthetically made, and while they do not have the same amount of stated health advantages as essential oils, they are generally less expensive and come in a far wider range of aromas.
Cosmetic micas are my first option for bath bomb coloring. Micas have a terrible reputation for not being as brilliantly colored or pigmented as other forms of colorants, but finding the appropriate sources is all it takes! (Note: Mad Micas has some incredible and incredibly vivid neon hues!) Other colorant possibilities include FDA-approved lakes and bath bomb-approved colours, which must be “bloomed” into the baking soda before used. Food coloring should not be used in bath bombs since it can discolor your bathtub and skin.
If you use colorants in your bath bomb recipes, especially micas, a small bit of Polysorbate 80 will assist the color disperse evenly throughout the water and avoid any discoloration or rings from forming around the bathtub.
The most common liquid binder for bath bombs is witch hazel, but you can also use a mixture of water and isopropyl alcohol (note: depending on your environment, using alcohol as a binder may result in “dustier” and more crumbly bath bombs). To get the mixture to the right consistency and assist bind the elements together, a small amount is applied using a fine-misting spray bottle.