Bath bombs are compact little balls that bubble and fizz when they’re tossed into a tub full of water. As they bubble, they release the contents of the bath bomb into the tub, filling it with the vegetable oils, butters, salts and essential oils contained inside. They look like they’re difficult to make, but once you get the hang of it, bath bombs are actually fairly easy to put together. That doesn’t stop manufacturers from charging a premium for them, as they can cost a small fortune in the store, with some companies charging as much as $10 to $15 per bath bomb. When you make them at home, you can get the cost down to a buck or two per bath bomb. There are only 6 ingredients that go into making a basic bath bomb:   Baking soda. Citric acid.  Corn starch. Epsom salts. Vegetable oil. Water or witch hazel.   Of those 6 ingredients, the 2 key ingredients are the baking soda and the citric acid because they’re the ingredients that make the magic happen. Combine them when they’re dry and nothing happens. Add water to the equation and a chemical reaction occurs that creates carbon dioxide. The effect you get when you throw a bath bomb in the tub is similar to that of carbonation in a soda, as the carbon dioxide bubbles pour out of the bath bomb and into the water. The corn starch is added to provide buoyancy, as most people prefer their bath bombs to float at the top of the tub. When the corn starch is left out, a bath bomb will still create bubbles; it’ll just do so from the bottom of the tub. Epsom salts are added to provide volume and because they’re good for the skin and for the body. A bath with Epsom salts in it is relaxing and can help relieve stress. Other natural salts like Himalayan pink sea salt can be substituted for the Epsom salt to good effect. Vegetable oils are used as carrier oils to disperse the essential oils and other bath bomb ingredients into the tub. These carrier oils carry essential oils deep within the skin, where they can be absorbed into the blood stream and carried throughout the body. Certain butters can also be added to bath bombs to ensure they moisturize the skin and leave it feeling supple and smooth. The last ingredient required to make bath bombs is either water or witch hazel. This ingredient is added to the bath bomb mixture to make sure it’s damp enough to where it can be pressed into the mold and will retain its shape until it’s had a chance to dry. When adding water or witch hazel to a recipe, it’s important to only add a little bit at a time or you could set off the reaction between the baking soda and the citric acid. If this happens and you start to see bubbles, you can usually stop the reaction by quickly stirring the area that’s bubbling. All other ingredients are optional, and are added to create a certain effect. Dyes, clays and other colorants can be added to fill the tub with color; essential oils and fragrance oils can be added for scent; and dried herbs and flowers can be added as garnish. We’ll discuss a number of these ingredients as we use them in the recipes.