How to Make a DIY Rainbow Bubble Bar (That Actually Bubbles!)

If you’re obsessed with all things colorful and fizzy, you’re going to love this DIY Rainbow Bubble Bar recipe. Inspired by those dreamy bath treats from LUSH, these bubble bars are just as vibrant, smell heavenly, and yes—they create real bubbles in the bath (not just foam that fizzles out in 10 seconds). And the best part? You can make a whole batch for the cost of one store-bought bar.

Whether you’re crafting for a gift, stocking up your bathroom stash, or just feeling a bit rainbow-obsessed (guilty!), this is a fun afternoon project that’ll bring a little colour therapy to your tub time.

Why You’ll Love This Lush Dupe DIY Bubble Bar Recipe

It actually bubbles, thanks to the magical SLSA (Sodium Lauryl Sulfoacetate—not to be confused with SLS)

Bright and swirly—think Lisa Frank meets bath therapy

Gentler ingredients than commercial bars

Customizable with essential oils or skin-safe fragrance blends

Way cheaper than buying from Lush or other high-end bath shops

Ingredients You’ll Need

1 cup baking soda

1/2 cup cream of tartar

1/2 cup cornstarch

1/4 cup SLSA (wear a mask for this—it’s a fine powder!)

2 tablespoons vegetable glycerin

1–2 tablespoons coconut oil or shea butter, melted

1 teaspoon polysorbate 80 (optional, but helps prevent color staining in the tub)

Skin-safe colorants (micas or gel dyes work best)

Essential oils or fragrance (lavender, citrus, or bubblegum are fab choices)

Plastic wrap or wax paper for rolling

Step-by-Step: Make Your Own Rainbow Bubble Bars

1. Mix the Dry Ingredients

In a large bowl, combine baking soda, cream of tartar, cornstarch, and SLSA. Mix gently so the powder doesn’t fly everywhere.

2. Add Wet Ingredients

Add melted coconut oil (or shea butter), glycerin, polysorbate 80 (if using), and your fragrance oil. Mix until the texture feels like soft dough—moist enough to hold together, but not sticky.

3. Divide & Colour

Split your dough into 5–6 bowls. Add a tiny amount of color to each batch and knead until the color is even. (Gloves help here!)

4. Roll & Layer

On a piece of wax paper, flatten each color into a rectangle. Stack them in rainbow order, then roll it all up like a cinnamon roll.

5. Slice

Cut your log into thick slices, and gently press the layers together if they start to separate.

6. Drying Time

Let your bubble bars air-dry for 48–72 hours until they’re firm and hard to the touch.

How to Use Your Bubble Bar

Break off a chunk (about a golf ball-sized piece) and crumble it under warm running water. The more pressure, the better the bubbles! For a bubble bonanza, agitate the water or use a sieve under the tap.

Tips for Success

Humidity matters – Make these on a dry day to avoid a sticky mess.

Storage – Keep in a cool, dry spot. A glass jar with a lid works beautifully (and looks cute on the counter).

Color Control – Use just a pinch of mica. Too much dye = stained tubs and sad towels.

Custom Scent Ideas

Unicorn Dreams: Lavender + Vanilla + Cotton Candy

Rainbow Citrus: Orange + Lemon + Lime

Zen Garden: Ylang Ylang + Patchouli + Peppermint

These rainbow bubble bars are one of my go-to DIY bath gifts. My daughter helped me roll the last batch (with rainbow sprinkles on top), and we wrapped them in cellophane with a little note that said “Keep Calm and Bubble On.” They were a hit at the school fundraiser!

Want to turn this into a fun activity with the grandkids? Just prep the dough ahead of time and let them do the rolling and layering.