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Everyone loves baths. And few things make them better than bath bombs, those delightful chunks of good-smelling stuff that explode into colorful fizz in your tub. You can find them at discount stores, beauty shops, and drugstores, but crafting your own is way more fun.
Buying the necessary ingredients in bulk and learning how to make bath bombs will get you a lot more bang for your buck, and add a personal touch to your bath blasts. Plus, you can customize color, scent, and shape to perfectly suit any holiday or a lucky recipient’s preferences. Also, no one will know if you save a couple dozen for yourself.
This bath bomb recipe makes about 12 orbs of colorful fun, but the exact count will depend on the size of the silicone bath bomb molds you use.
- Time: 10 minutes of work, and at least 4 hours of drying time
- Cost: about $2 per bomb if you make a dozen
- Difficulty: easy
- 8 ounces of baking soda
- 4 ounces of Epsom salt
- 4 ounces of cornstarch
- 4 ounces of citric acid
- 2.5 tablespoons of vegetable oil
- About 1 tablespoon of water
- (Optional) about 2 teaspoons of essential oil
- (Optional) 4 to 6 drops of food coloring
- (Optional) biodegradable glitter
- (Optional) dried flower petals
How to make bath bombs
1. Mix the dry ingredients. Pour the baking soda, Epsom salt, cornstarch, and citric acid into a large bowl and whisk them to ensure there are no clumps.
Baking soda, also known as sodium bicarbonate, is what will make your homemade bath bombs explode: When the high pH powder reacts with a low pH acid, it produces carbon dioxide bubbles. Remember those baking soda and vinegar volcanoes you made in elementary school? The citric acid in this recipe takes the place of vinegar in this chemical equation, but it doesn’t react with sodium bicarbonate until it gets wet.
[Related: Make your own seed bombs to garden on the go]
2. Add dry decorations. At this stage, you can add decorations like biodegradable glitter or dried flower petals, or herbs into the mix. Just don’t use regular-old craft glitter, because it’s no good for our friends in the ocean.
- Note: More decorations can make for more fun and interesting bath bombs, but more ingredients will elevate the cost per fizzy orb.
3. Pour the oil and water into a jar. You can use any vegetable oil you like, but one rich in fatty acids and vitamins (you may have one in your kitchen) will add extra moisturizing powers to your bath bombs.
4. Add scent to the jar of wet ingredients. This is a critical step, because a bath bomb that smells bad is basically a wet stink bomb. You can tweak the proportions to suit your taste, but you should only use about 2 teaspoons of essential oil or perfume in total. You can try cinnamon, cocoa, peppermint, or coffee scents for the winter holidays (or a combination of all four to make mocha-licious bath bombs). You could also go with something classic, like a spa-like eucalyptus and lavender mix or a straight-up sugary hit of vanilla extract. The possibilities are truly endless.
5. Choose your bath bombs’ color. Feel free to mix up different hues, but stick to 4 to 6 drops of food coloring total, or else you’ll risk muddying the bath waters.
When you’ve decided on a color and fragrance combination you like, add the food coloring and essential oil to the jar of wet ingredients. Put the lid on and close it tightly, then shake the jar to ensure all the ingredients mix well.
6. Slowly combine the liquid and dry ingredients. Add the contents from the jar into the bowl really slowly—like a teaspoon at a time. You don’t want your DIY bath bombs to explode prematurely. Whisk as you go, and slow down if things start to look fizzy. You should end up with a mixture that just barely clumps together, like damp sand.
7. Stuff that stuff into your silicone bath bomb molds. Do this ASAP. Press the mixture down firmly into your molds to make sure there are no air pockets. Be especially careful if your mold has an intricate design, as filling all the nooks and crannies can be tricky.
- Pro tip: It’s important to have enough molds to make a dozen or more bath bombs at once, so err on the side of having too many. If you find yourself with leftover mix and no molds to put it into, it’ll dry out and you’ll need to start troubleshooting. You can try slowly rehydrating the mix by spritzing it with witch hazel.
8. Let your bath bombs dry. Make sure you let the molds sit in a dry place for at least four hours, as excess moisture can result in crumbly bombs that won’t hold their shape. Molds with many details might take longer to dry, so you may just want to let them sit for a whole day to be safe.
9. Pop your bath bombs out of their molds. Make sure your bath bombs are dry, and carefully extract them.
10. Gift and enjoy. Throw one into the tub and enjoy the explosive fruits of your labor. Bag the rest of your DIY bath bombs in cellophane and make your friends and family love you forever.
This story has been updated. It was originally published on December 16, 2016.