What is “Activation”? Here’s How You Can Avoid It

How to keep your bath bombs in perfect condition and avoid accidental activation

If you’ve ever had your bath bombs expand, fizz or lose their shape during your creative process, you’ve experienced what’s known as activation. 

Activation happens when the ingredients in your bath bomb react prematurely, often due to the presence of excess moisture or unsuitable environmental conditions. While frustrating, activation can be controlled with the right techniques and preparation. Here’s how:

Precision Is Key 🗝️

One of the most common causes of activation is adding too much water. Guessing your water content can lead to disaster, so it’s crucial to weigh it accurately. 

For a standard recipe (like the one many makers use with around 1200g of bicarbonate of soda) aim for 16–18 grams of water. But keep in mind that every recipe and environment is different. Some makers use as little as 2g per 1kg of mix, while others find success with higher amounts.

Monitor Humidity Levels 👀

Environmental factors, particularly humidity, play a huge role in how your bath bombs behave. Ideally, the humidity in your workspace should be between 44% and 48%. 

Too much moisture in the air can trigger activation even before you’ve added any liquids, so always switch on a dehumidifier before starting and make a note of the humidity level on your log sheet for future reference.

Keep a Detailed Log 📝

Tracking your process will help you fine-tune your technique over time. Make a note of:

• How much water you used.
• The environmental conditions, including humidity.
• How your bath bombs reacted (e.g. no reaction, slight reaction, or full activation).

By doing this, you’ll build a clearer picture of what works in your specific environment and can adjust future batches accordingly.

Work in Small Batches 🤏🏼

If you’re just starting on your cosmetic journey, it’s a good idea to work in small batches until you have control over activation. 

This approach minimises waste and gives you a chance to test variables like water content and drying conditions without risking an entire batch.

Handle Drying Carefully 💨

Once you’ve shaped your bath bombs, cover them as soon as possible. Use cling film or store them in plastic boxes to keep external moisture at bay. 

Ensure they dry in a well-ventilated space, away from windows, kettles, or any source of heat or steam.

Repurpose Activated Bath Bombs 🛁

Don’t worry if you experience slight activation, it’s not the end of the world! Activated bombs can be turned into dust or blocks, so no materials are wasted.