How To Make Bath Bombs Harder (Fizz Longer)

If you’d like to make your own bath bombs at home and you don’t know how to make bath bombs harder or fizz longer, then I will explain to you the process of doing just …

How To Make Bath Bombs

If you’d like to make your own bath bombs at home and you don’t know how to make bath bombs harder or fizz longer, then I will explain to you the process of doing just that in this helpful guide!

Enjoying a good, long soak is something that more and more people are coming to appreciate. There are a ton of benefits to be had from soaking in the bathtub once in a while.

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From mental health benefits to muscle relaxation, it is becoming a must to soak from time to time. To enhance the experience, some people like to dabble in additives.

It may be essential oils with specific health benefits or ones that simply provide a fresh, vibrant aroma to add to the overall experience. For others, there is the implementation of bath bombs.

Bath bombs are these round balls that dissolve when dropped into the bathtub. They come in different scents and some even have different benefits when it comes to aiding relaxation and stress relief.

Some of them can fizz and dissolve far faster than we like, though. So, if you are looking to make your bath bombs harder or fizz for longer, there are a few things that you can do.

How to Make Bath Bombs Harder

How To Make Bath Bombs Harder (Fizz Longer)
Bath balls and candle

One of the keys to making your bath bombs last longer is to make them harder. There are a few keys to achieving this.

For one, keeping the moisture out helps them last longer. For two, there are ingredients that you can add that reduce the amount of moisture within your bath bomb.

There are three ways in particular that you can not only limit the amount of moisture trapped in the bath bomb but prolong them. The harder they are, the more time you get to spend with that wonderful bath bomb doing its thing.

  1. Reduce Liquid Ingredients

This is for those who like to make their own bath bombs. The first thing that you should do is limit the ingredients that harbor more liquid.

The less moisture that gets trapped within your bath bomb, the harder it is. The harder it is, the longer it lasts. For the most part, there are standard ingredients to constructing your own bath bomb.

They include citric acid, baking soda, water clay (kaolin clay) or cornstarch, vegetable oil, food coloring, mixing and measuring spoons, four bowls, an ice cube or muffin tray, medicine dropped, warm water for testing it out, and any optional ingredients such as Epsom salts or fragrances.

When you are trying to harden your bath bomb, the key is to add in the right amount of each. When you go too much in one direction, you don’t get the optimal results.

Also, try to stay out of humid spaces and limit your wet ingredients. That said, if you go too far in the direction of dry ingredients, your bath bomb may be brittle and dry.

Cream of tartar mixed in with the ingredients has been shown to make bath bombs harden. Also, keep in mind that if you add things such as Epsom salts, they pull moisture in, so try to avoid them if possible.

If you are going to use wet ingredients, it is a good idea to use the ones that are fast evaporating because they prevent premature fizzing. Add your wet to dry, not the other way around. You can know how hard the mixture is this way.

  1. Proper Storage

How you store your bath bombs plays a key role in how long they last. Make sure that you keep them sealed so that moisture cannot get into the container.

The less moisture they suck in, the harder they will be and the longer they will last. The best way to do this is to store them in a plastic bag or another airtight container.

With a proper airtight seal, make sure to keep them in a dry, cool place that maintains a normal room temperature (something in the 73 degree Fahrenheit area). Garages, cabinets, and basements usually fit this bill.

You can also use silica gel to keep your bath bombs stored. You may notice that medicines, bags, and some other things have little bags that are full of small crystals.

Those are silica gel. The idea is that the silica gel absorbs the moisture that would otherwise go into the product. Throw a bag with silica gel into your container so that, should any moisture get in, the gel will suck it up.

Just make sure that you don’t drop that silica gel into the water with you. It is not a good thing to have on your skin. You can also blow dry your bath bombs to get rid of any moisture that would have otherwise permeated the bath bomb.

Just be careful because you can make your bath bomb too dry. When there is not enough moisture within, it can become brittle and will more often than not crumble. Just a few minutes should be more than enough.

Finally, you can also use a dehumidifier. They work to pull the excess moisture from the air in that given room. So, if the area you live in is a humid one, you can keep a dehumidifier in the room where you store your bath bombs.

Just make sure that you don’t turn it to the highest setting because it can make the air too dry and cause you irritation.

  1. Use Before Expiration

When you properly store bath bombs, you can get long-term usage out of them. In optimal storage conditions, you can use a bath bomb up to six months after you made or purchased them.

That means enjoying them whenever you want. That said, if you keep them in storage longer than six months, they can start to lose that fizziness and freshness even if they are kept in the right storage conditions.

The ingredients within the bath bomb will eventually start to deteriorate and some of the natural ingredients will even go bad.

You might think of adding some kind of preservative into your mixture either during the making of your bath bomb or after you’ve purchased one.

Of all the preservatives, citric acid is probably the best to mix in and that is already in your mixture. If you add something such as Polysorbate 80, you may only wind up adding negative side effects that you don’t want.

How to Make Bath Bombs Fizz Longer

How To Make Bath Bombs Harder (Fizz Longer)
Bath bombs in water

The hardness is a major factor in the longevity of bath bombs. There is also the matter of how long they fizz. We all enjoy that light fizzing action as we soak, adding to the overall experience of soaking in the bathtub.

But how can you make your bath bombs fizz longer? There are a few factors that come into play. Despite what you have heard, you can ignore water temperature, at least for right now. There are a couple of factors that come into play.

First is the density of the mixture. You would also want to add cornstarch while leaving out salts and not using oil at all. You can change the citric acid/baking soda ratio, or even add SLSA.

Each element can impact between the baking soda and citric acid as it comes into contact with the water, which ultimately triggers the fizzing action.

  1. The Density

The density of the bath bomb is crucial to fizzing time. The more compacted that the mixture is when it is in the mold, as well as the harder that the finish is when it dries, the harder it will be for water to get in and break up the mix.

The harder it is for water to get in and break up the mix, the longer it will fizz. No more bombs breaking up after just a few minutes, adding to the overall experience. Remember that the longer your bath bomb fizzes, the longer you get that truly relaxing experience.

  1. Adding Cornstarch

Cornstarch is a bonding agent. It bonds to the baking soda and citric acid in a very valuable way. The mixture ensures that the water has a more difficult time combining together with the other reactionary agents.

When those reactionary agents are triggered, that is what leads to the fizzing of the bath bomb. The quicker they react, the shorter the time they have before they ultimately break apart and stop working.

There are a ton of DIY recipes out there where you can add cornstarch to your mix. Those will slow down the fizz of the bath bomb, allowing it to last for far longer.

  1. Avoid Epsom Salts

There are many benefits to using Epsom salts in your bath. But they are actually quite detrimental to the life of your bath bomb. That is why avoiding them is probably the best thing that you can do for a fizzier bath bomb experience.

You would want to avoid using salts in general. That’s not to say that it is the difference between a fizzy bath bomb and one that lasts a long time, but they do play a factor.

When you add salt into your mixture, that is just more sodium that gets added in. The good news is that the salt is still not nearly as reactive as baking soda.

If you must use Epsom salt, make sure to use it in small doses. Going with too much will impact the fizz and doesn’t add enough to counteract the lost fizz.

  1. Don’t Use Oils

Remember that moisture is the key to bath bombs. The less moisture that gets trapped in your mixture, the harder it will be and the longer it will fizz.

Oils are another binding agent that, in this case, can actually slow the reaction down, albeit slightly. The oil is really up to the user. Taking oils out entirely means that there will be no scent.

With the use of essential oils, you would have to use a secondary oil (a carrier oil) such as coconut oil to “carry” the essential oil into the mixture.

Too many oils can impact the dissolve time of the bath bombs. If the fragrance doesn’t matter much to you, skipping the oils may be the best step.

That would prolong the fizzing action, though you would miss out on the benefits that the essential oils have. Go conservative in the addition of your essential oils and you should do just fine.

  1. Changing the Ratio

For the most part, you will find bath bomb recipes that suggest the baking soda and citric acid be at a 2:1 ratio. If you want to experiment with getting a fizzier reaction out of your bath bombs, you may try switching up those ratios.

That is not to say going in a drastic direction – you wouldn’t want to go 20:1, for instance – but a slight change one way or another could lead to more prolonged results.

When you move the ratios up or down, you will notice that there is either more or less reaction between those two ingredients. When you make your own bath bombs, you should take the time to play around a bit.

Just because a certain ratio worked well for one person does not mean that it will work out well for you. When you try things out, you can perfect your bath bombs to fit your needs specifically.

  1. Add SLSA

Plenty of other people simply add sodium lauryl sulfoacetate (SLSA) to the mix. SLSA, helps to create more bubbles in the water. Given that this is the entire role of bath bombs, it only makes sense to give them more bubble-making power.

Just be careful not to add too much to the mix or the bubbles can wind up becoming a distraction more than a benefit. Remember it is all about finding that ratio that works best for our own individual needs. That can take time and some troubleshooting.


Now that you know how to make bath bombs harder or fizz longer, you can comfortably and cost effectively make your own bath bombs at home without worrying that they’ll fail on you!

And at the end of the day, it all depends on where you are getting your bath bombs. When purchasing, storage is key. When making your own, it comes down to the ingredients that you opt to use within your bath bombs.

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