Here is the recipe for the bath bombs Ike made the other day. I first tried this recipe about 5 years ago and gave these to friends and relatives for Christmas. It is really easy and is a project that kids can do with supervision. It can take a bit of trial and error to get the amount of water right, and it is always best to error on the side of too little rather than too much.
(makes 6 muffin tin sized bath bombs)
1 1/2 cups Baking Soda (sodium bicarbonate)
1/2 cup citric acid
30 drops fragrance oil or essential oils
food colouring (optional)
water (in a fine misting spray bottle)
Combine baking soda, and citric acid in a bowl and mix well. Add food colouring (if using) start with 6-8 drops and work in with gloved hands. You can do this in a large ziploc bag squeezing and working the colouring through the powder just as you would when colouring sugar. Do the same when adding the fragrance or essential oils. Once the mixture is homogeneous begin to spray water with a fine mist sprayer onto the surface of the powder. Stir the mixture with your hands to bring dry powder to the surface and spray some more. You will have sprayed enough when you can squeeze a small amount of the mixture in your hand and the powder stays together in a clump. Once this happens, DO NOT spray any more. Pack the mixture into molds and press in very hard. The more firmly they are packed, the better! They will be stronger the more firmly packed they are, and will be less likely to prematurely crumble. Release from molds onto waxed paper lined cookie sheets and let dry for 8 hours.
In my batch I used these ingredients, but you can use what ever you like.
10 drops red food colouring
15 drops patchouli essential oil
8 drops tangerine oil
10 drops lemon grass
the contents of one camomile tea bag
This combination smells like something you would find at lush and has a bright citrus and floral smell. The most time consuming part or the entire process is working the food colouring evenly through. You could likely do this in a blender, but I would NOT add the fragrance oils or essential oils in a blender unless that blender is solely used for craft purposed and not used for food preparation. You can make individual balls by hand (like making snow balls) but you must pack them very tight. You can buy actual bath bomb molds (ball type) at some hobby stores and I have seen them at times in Walmart. But muffin pans works very well, especially the cute seasonal pans Wilton makes. I have used the snowman muffin pans from Wilton which are very cute for Christmas time. They have cute heart pans for Valentines as well. The baking soda is very inexpensive when purchased at the bulk food section of the grocery store and they should also have citric acid available in the pharmacy section. If the citric acid is not available there most health food stores would have some, although I think the pharmacy might be less expensive. Essential oils are available at health food stores and sometimes in the pharmacy section of the grocery store in the homeopathic section. If you decide you really love making bath bombs and want to buy large quantities of essential oils you are better off looking on line.
As I eluded to earlier if you add too much water to the mix, it will become sticky and more difficult to work with. Also and most importantly it will probably stick in the molds. If this happens you can pack them into cookie cutters and you will more easily be able to push them through after packing them in hard. So err on the dry side, as long as it will clump when you squeeze it together, you are good to go. If you pack them in and they won't stay together, you can always dump it back into the bowl and spray more water.