Every Christmas we always end up watching at least one, if not two or three versions of the Grinch story. With the new Grinch movie in theatres, the excitement has been even higher. So for our latest bath bomb project we decided to tackle fun Grinch Christmas Bath Bombs that include special little soap hearts we made. It was fairly easy with fantastic results that are great for gifting.
GRINCH BATH BOMB RECIPE
Disclaimer: This article may contain commission or affiliate links. As an Amazon Associate I earn from qualifying purchases.
Not seeing our videos? Turn off any adblockers to ensure our video feed can be seen. Or visit our YouTube channel to see if the video has been uploaded there. We are slowly uploading our archives. Thanks!
This bath bomb recipe is one of our top picks for Christmas Bath Bombs. Check out the whole list here.
Once you start making bath bombs it becomes such a fun obsession! The kids love playing with different ingredients, recipes and techniques. And boy have we created some fun bath bombs! The latest one is inspired by using the combination of bath bombs and soap making together. We did this with the Monster Eye Bath Bombs with great success so we decided to try it again with a new twist.
The first step was to make homemade soap hearts. We over made our soap mix, so we also made some kitty soaps. These are great little soaps that can be used as guest soaps or bundled up in little gifts. Then we made the bath bombs. And they worked! YEAH!
A NOTE ABOUT DRY WINTERS AND BATH BOMB MAKING
Our temperatures are changing and winter is definitely here. Which also means it is very dry. Like cracked lips, skin dehydrated crazy dry. So we ended up having to add a bit of extra coconut oil than our recipe usually calls for. If you run into the same issue, just remember, a little goes a LONG way. So add just a teaspoon extra at a time if you find your mix is too dry.
Another funny thing happened during the making of these bath bombs. Half way through the bath bomb mixing and packing process I took a break to wash my hands (and deal with some crazy kittens). Thing is, I didn’t completely dry my hands. There was some drops of water left on my hands and it caused some of the mixture to react creating bits of white on a couple of our bath bombs. Oops!
Remember bath bombs are triggered by water. So water during the making process is the enemy and will cause premature reactions. This includes water in the air. If you live in a humid place, you will need to take extra precautions to keep moisture away as much as possible.
THE SCIENCE OF BATH BOMBS
So what exactly is going on with bath bombs? They are a simple base – acid reaction. However since the ingredients are dry when packed into the mold, they do not react. They require the addition of water to trigger the reaction. It’s some fascinating chemistry and one of our favourite parts is adding water to the left overs in our mixing bowl and watching the eruption!
You can learn more about the science of bath bombs in our Bath Bomb Science Fair Project.
GRINCH INSPIRED CHRISTMAS BATH BOMBS INGREDIENTS & SUPPLIES
2 cups baking soda (sodium bicarbonate)
1 cup citric acid
1/2 cup cornstarch
1/4 cup cream of tartar
1/4 cup fine Epsom salts
1/3 cup coconut oil
1 tablespoon polysorbate 80
20 drops peppermint essential oil
Green mica powder
Bath bomb molds
3-4 cubes of clear melt and pour soap base
Red soap color
Silicone heart mold
Spray bottle filled with rubbing alcohol
Large mixing bowl
Small mixing bowl
Microwave safe bowl or measuring cup
2 mixing spoons
Parchment paper (optional, but helps with clean up especially when kids are helping)
CHRISTMAS BATH BOMBS WITH GRINCH HEART SOAP DIRECTIONS
Cover the work area with parchment paper if desired. This helps with clean up. This entire creation process took about 2 hours, plus overnight to set. It made about 6 bath bombs with standard sized molds. Depending on the size of your molds your results may vary slightly.
STEP 1 – Making Soap Hearts
The first step is to make the soap hearts. Begin by cutting about 3 or 4 cubes from your soap based. Place them in a microwave safe measuring cup or bowl. Microwave in 30 second intervals, stirring in between until completely melted. Ours was completely melted after only one 30 second interval.
Add a few drops of peppermint essential oil and 2 drops of red soap colouring. Mix well. If desired add more soap colouring, but remember a little goes a long way, so one drop at a time.
Carefully fill your heart molds approximately halfway. We don’t want to fill them completely because we want the final soaps to be pliable.
Spray the top of the soap with rubbing alcohol to prevent bubbles forming.
Let set for 45 minutes to 1 hour.
Once set remove from the molds. It is now time to make the bath bombs!
STEP 2 – Making the Bath Bombs
In the large mixing bowl, add baking soda, citric acid, cornstarch, cream of tartar and Epsom salts. Do this in a well ventilated space if kids are helping. The powders like to become airborne with excited kids are helping!
In a small mixing bowl combine the coconut oil (we had to melt ours in the microwave for 10 seconds because it was very solid), 20 to 40 drops of peppermint essential oil (depending how strong you want the final scent), and polysorbate 80.
Coconut oil binds all the ingredients together, so your bath bombs don’t crumble when you touch them. Polysorbate is an emulsifier that helps mix the oil with the water. Something oil and water don’t naturally do. If you don’t use Polysorbate 80 the oils will float on the top of your bath water and stick to the sides of the tub rather than mixing in nicely. And no one wants a scum layer in their bath!
Add the oil mixture to the dry mix in the large bowl.
Mix the ingredients together. I use my hands to break down any lumps and make sure everything is really mixed in there. The mixture is perfect when it holds together when you press it into your hands and feels like wet sand.
Now add your green mica powder and mix it in well until the colour is evenly dispersed.
It’s time to pack your bath bombs!
Start by placing a heart soap in the end of the mold and press it in so it curves. Now pack the bath bomb mold with the green mixture. Fill the other side with more of the green mixture. Now place the two halves together, twist and grind them together to get the two sides to adhere to each other and remove any excess mix.
Tap the end of the mold with your finger a couple of times, then carefully pop the bath bomb out of the mold. Set out somewhere dry and warm to harden overnight.
Check out this quick video on how to pack bath bombs
With a bit of practice using bath bomb molds is easy, but it does take a few tries! I didn’t get a video of us making this specific bath bomb but you can see the technique from when we made our Pumpkin Bath Bombs.
USING YOUR CHRISTMAS BATH BOMBS
To use, run a warm bath and add your bath bomb! Your little heart soap will float up from the bath bomb after a few moments so you can clean yourself with it! The little soap heart is the perfect size for one time use.
These make wonderful gifts and stocking stuffers. Wrap them in plastic to help keep moisture out or store in an airtight container. These are best used within 2 to 4 weeks (ours never last a full week!). The older the bath bombs get, the less fizzy the reaction. So keep that in mind if you are planning on gifting these. We are planning on making a big batch of Christmas Bath Bombs in those last few days before Christmas when excitement is high, but most of the busyness hasn’t started yet.
All the best for a wonderful holiday season with those you love!
MORE BATH BOMB RECIPES FOR KIDS
Grinch Bath Bomb with Soap Heart
A wonderful Grinch activity creating Grinch inspired bath bombs with a soap heart
- 2 cups baking soda (sodium bicarbonate)
- 1 cup citric acid
- 1/2 cup cornstarch
- 1/4 cup cream of tartar
- 1/4 cup Epsom salts
- 1/3 cup coconut oil
- 1 tbsp polysorbate 80
- 20 drops peppermint essential oil
- 1 tsp green mica powder
- 4 oz clear melt and pour soap 1 cube equals one ounce
- 2 drops red soap colourant
Cover the work area with parchment paper if desired.
Making the Soap Hearts
Cut 3 or 4 cubes from your soap based. Place them in a microwave safe measuring cup or bowl. Microwave in 30 second intervals, stirring in between until completely melted.
Add a few drops of peppermint essential oil and 2 drops of red soap colouring. Mix well.
Spray your mold with rubbing alcohol. Carefully fill your heart molds approximately halfway. Then spray the top of the soap again with rubbing alcohol.
Let set for 45 minutes to 1 hour. Carefully pop the soaps out of the mold.
Making the Grinch Bath Bombs
In the large mixing bowl, add baking soda, citric acid, cornstarch, cream of tartar and Epsom salts. Mix.
In a small mixing bowl combine the coconut oil (melt in the microwave if it is solid), 20 peppermint essential oil and polysorbate 80.
Add the oil mixture to the dry mix in the large bowl. Mix well using your hands to really combine it. The mixture is perfect when it holds together when you press it into your hands and feels like wet sand.
Now add your green mica powder and mix it in well until the colour is evenly dispersed.
Packing the Grinch Bath Bombs
Place a heart soap in the end of the mold and press it in so it curves.
Now pack half of the bath bomb mold with the green mixture until it is loosely heaped. Fill the other side with more of the green mixture until it is also loosely heaped. Now place the two halves together, twist and grind them together to get the two sides to adhere to each other and remove any excess mix.
Tap the end of the mold with your finger a couple of times, then carefully pop the bath bomb out of the mold.
Let set somewhere warm and dry for at least 24 hours. I often leave them 48 hours just to be sure they are nice and hard.