Stop Sinking Bath Bombs with These Top Tips

Overcoming one of the most frustrating challenges for bath bomb makers

You’ve spent time perfecting your mix, shaping your bath bombs and adding vibrant colours, only to watch them sink to the bottom of the tub. So, what’s going wrong? 

With the following adjustments, you can prevent your bath bombs from sinking and ensure they float and fizz beautifully every time. 

Get the Right Consistency

One of the most common causes of sinking bath bombs is the wrong consistency of your mixture. If your mix is too wet, it can cause your bath bombs to become too heavy, resulting in them sinking. 

So, always ensure that your mixture holds its shape but isn’t overly damp. The key is to achieve the perfect balance of moisture, just enough for the mix to clump together when squeezed, but not too much that it starts fizzing prematurely.

Check Your Pressing Technique

How you press your bath bombs into their moulds is just as important as the mixture itself. For example, pressing too hard can cause your bombs to become compacted and dense, leading to sinking when placed in water. 

Try pressing your bath bombs lightly into the moulds, ensuring they’re firm enough to hold their shape but not so dense that they weigh themselves down. A gentle, even pressure helps maintain the right texture.

Consider Your Ingredients

The ingredients in your bath bomb mix can also play a big role in whether or not it will float. 

Too much bicarbonate of soda or a lack of cornstarch can make your bath bombs too heavy. On the other hand, using a small amount of Epsom salts or other heavy salts could make them denser. You may need to adjust your recipe by reducing or replacing certain ingredients to achieve a lighter, float-worthy bomb.

Allow Adequate Drying Time

If your bath bombs aren’t dry enough, they can be more prone to sinking, so make sure your bombs are fully set and dry before use. 

This is especially important if you live in a humid environment. Allow your bath bombs to cure for at least 24-48 hours in a cool, dry area to ensure they are solid and dry enough to float when placed in water.

Use Less Water in the Mixture

Adding too much water to your bath bomb mix can lead to excessive fizzing, which disrupts the integrity of your bomb. Additionally, it can make your bath bomb heavier, causing it to sink. 

Always measure your water carefully and aim for the minimal amount needed to activate the mixture without compromising its texture. Keep your water-to-dye ratio low, especially when using water-soluble dyes.