In this tutorial I’ll show you how to make bath bombs using moon cake molds! Have you seen them yet? Moon cake molds are little presses with detailed imprints for cakes. B&B formulators have been using them to make bath bombs with stunning results! So I had to give it a try.

You can order the presses on Amazon. Here is the set that I ordered. But there are tons! Do a search for moon cake molds and you’ll find all sorts of sizes and designs.

Easy Bath Bombs (Bath Fizzies) Using a Moon Cake Mold Press

This bath bomb recipe is super basic. It is great for beginners, or for someone who wants a no-fuss recipe to test out these awesome cake presses.

This recipe doesn’t contain hardeners (we’ll have a recipe soon that works better in humidity), so don’t make this recipe when it is humid. 🙂 If the humidity if over 60% where you live, you might have some issues.

If you still want to try them, here are a couple of tips for drying them quickly so they aren’t affected by the humidity as much.

  1. Line a baking sheet with sea salt. Place your bath bombs on the salt; this will help dry them quickly.
  2. Place your bath bombs in a warm oven to dry them quickly. This has been hit or miss with me; but give it a try.

Lovin’ Soap’s Easy Bath Bomb Recipe

  • Baking Soda – 1 cup
  • Citric Acid – 1/2 cup
  • Avocado Oil – 1/2 teaspoon (or any liquid oil of your choice)
  • Fragrance – 1 teaspoon (I used lavender essential oil)
  • A spray bottle with alcohol. Some people use witch hazel; I just think alcohol makes a harder bomb.

This recipe makes about 12 bath bombs (depending on how much you pack them) using the moon cake mold press. Each bath bomb weighs about 1 oz. – 1.5 oz.

So here is how it went! I’ve heard of some people having a hard time with the presses using their recipe. This recipe worked perfectly and kept the detail from the press!

In a mixing bowl, measure out the baking soda, citric acid, avocado oil and fragrance.


Mix until completely blended using a whisk. Then mix some more.

Test your mixture. The mixture should feel a bit like damp sand (not wet sand!). Pick up some of the mixture and squeeze REALLY hard. Does it stay together or fall apart?

If it stays together, great! If it falls apart, spray with alcohol.


Mine fell apart in the picture above. I sprayed with alcohol while mixing, testing every five or so sprays. I ended up using about 15 sprays. Since all spray bottles are different…test often.


Let’s test it again.

Now it is perfect! Not too wet that it is mushy and not too dry that it crumbles. This really is the most important part of making bath bombs. You have to get the moisture right.

Time to mold using the press!

Put your mold together using the imprint that you want. Pack the mold with your mixture. You’ll have to turn the press downward, so if you don’t pack it enough it will just fall out.

Pack it until the mixture stays.


Press onto a cutting board or other hard and flat surface.


Press firmly and steadily! Press some more!

I’ve found that with this press the bomb doesn’t just drop out. You’ll have to pull the base up while pressing. (That might not make sense, but you’ll see what I mean once you try it. It happens naturally.)

Move quickly since we used alcohol in this base. You don’t want it to evaporate before you can get all of the bombs molded. If you double or triple the recipe, use a blend of 50/50 alcohol/water so that it doesn’t evaporate as quickly.


Soon you’ll have a whole army of bath bombs with beautiful designs! The press is easy enough to swap out the designs as you go.


The next bath bomb tutorial will be a bit more advanced. I want those new to making bath bombs to start simple and then move toward advanced tutorials and additives. We’ll add color next time and create a two-toned bath bomb.

Check out that detail!


Bath bombs can be finicky, so let’s talk troubleshooting.

Bath bombs expand and mushroom out. This is due to either too much moisture in your mix or too much humidity in the air.

Bath bombs get warts. Same as above.

Bath bombs crumble or crack after molding. You probably didn’t have enough liquid in your mixture.

If you’re having trouble making bath bombs in humid areas you can add cream of tarter to help harden them quickly. We’ll have a tutorial soon on adding that to your recipe.

Happy Bath Bomb Making!

-Amanda Gail