Though they come in a rainbow of colors, shapes, and sizes, all bath bombs share the same base elements. A combination of acids and bases provide the fizzing action, while powdered ingredients, such as milk powder, salt, or starch, provide filler. Finally, a binding agent works to keep everything packed tightly together. Aromatics, colorants, and other additives are often included as well, but really, you could create a basic bomb from just three ingredients: Baking Soda, Citric Acid, and water.
While plenty fizzy, such a simple bath bomb would be a little lack luster, especially compared to the amazingly creative bombs being made by artisans and crafters nowadays. By tweaking each component of a bath bomb, you can create truly uniqe recipes. We’ll go into detail on each element to show you how.
Acid & Base Combo
Theoretically, you could use any skin safe acid and base combination to create the fizzy bubbles that bath bombs are known for, but the classic pairing of Baking Soda and Citric Acid is tried and true. Start with a ratio of two parts Baking Soda to one part Citric Acid, and you are guaranteed to pack your bomb with fizzy action. The acid and base combo should make up between 60% and 90% of your total bath bomb recipe.
Powdered Ingredients
While not strictly necessary, powdered ingredients help to improve the benefits and texture of bath bombs. so I highly recommend including them in your recipe. Almost any skin safe powder can be used to amp up a bath bomb, but the most commonly used are Milk Powders, Salts, Starches, Clays, Honey Powder, Grain Powders, and Herb Powders. Choose your ingredients according to your imagination. Powdered ingredients can fill up to 40% of your total bath bomb recipe.
Colorants
Bath bombs are quite versatile when it comes to color. You can use both water based and oil dispersible colorants, but they must be used in different ways. Water Based Dyes, which are usually liquid, can be added to water based binding agents, or they can be added to the powdered ingredients using salt. Dye the binding agents or salts before adding them to the recipe. Liquid or powdered, oil dispersible colorants, such as Oxides, Micas, or Oil Dispersible D&C Dyes can be added to oil based binding agents, or they can be mixed in with almost any powdered ingredients. The amount of colorant that you add to the recipe can be adjusted to yield different shades of color. Just remember that using too much colorant could dye skin and bath fixtures. When in doubt, use less.
Something to keep in mind when choosing your colorants is the nature of each type of colorant. D&C and FD&C Dyes provide bright, bold color, but they can fade and bleed over time. Micas and Oxides are less likely to bleed.
You can also incorporate color into your bath bombs by working with naturally colored powdered ingredients. Many Clays and Herbs yield beautiful colors when included in bath bomb recipes.
Aromatics
Scenting bath bombs is equally versatile. The ingredients most commonly used to scent bath bombs are Fragrance Oils and Essential Oils, but bath bombs can also be scented with Absolutes, Attars, or CO2 Extracts. Light scents can even be added by using an aromatic binding agent such as Hydrosol or Floral Water. Finally, aromatic oils and butters can also help lend natural scents. Ingredients like Cocoa Butter or Organic Virgin Coconut Oil can add a subtle touch of scent to bath bombs.
When scenting your bath bombs, keep skin safety in mind. You should never use more Essential Oil or Fragrance Oil than is safe for one bath. Try to keep your aromatics at a ratio of 1 – 5% of your total recipe.
Additives
Visual elements, such as flower petals, sugar decorations, or whole herbs should be included with the powdered ingredients when calculating your formula. These ingredients can be added in with the other powders, or they can be embedded during shaping or molding.
Binding Agents
Pulling this all together are your binding agents. There are two types of binding agents commonly used in bath bombs, oil and water. Whichever agent is used, it should make up between 10% and 20% of your total recipe.
Oil Based Binding Agents
Hard Butters and Oils, such as Cocoa Butter, Shea Butter, or Coconut Oil, can be used to bind bath bomb ingredients without setting off their chemical reaction. They also add moisturising benefits to the bombs. Because these kinds of bombs will only harden when the oils cool and set, they are best molded individually. With a little practice, these types of bath bombs can be shaped with ballers or scoops, but it can be a little tricky. When using these binding agents, your bombs are likely to be softer and more fragile than when using water based binding agents.
Water Based Binding Agents
Because water sets off the chemical reaction within bath bombs, it makes using a water based wetting agent more than a little tricky. However, when done right, it results in rock hard bath bombs that are virtually indestructable. The hardness can vary depending on technique, ingredients, and mold shapes.
As mentioned earlier, any water based ingredient can be used as this type of binding agent. Hydrosol, Floral Water, or plain water are the best to use. It can also be helpful to add a little alcohol to the agent to ensure that it dries quickly.
Assembly
Start off by preparing all of your components individually. Combine your powdered ingredients, and create your binding agent. Next, slowly add the binding agent to the powders, continually stirring to keep the ingredients moving. If you are using an oil based binding agent, simply drizzle the liquid in a little at a time. For a water based binding agent, using a spray bottle works best. Wet the mixture a little at a time until it reaches the consistency of snow. The mixture should pack and bind in your hands, but it should not be too wet. When you’ve reached the right consistency, pack the mixture into molds, or shape it with scoops or ballers. Allow the bombs to air dry for 3 to 6 hours, and then should be packaged in air tight containers.
Basic Recipe
Use this basic formula to create your own unique bath bomb recipes!
- 1 part Citric Acid
- 2 parts Baking Soda
- 1 part Powdered Ingredients
- 10 – 20% Binding Agent
- 5% Aromatics
- Color as desired
Natural Beauty Workshop Recipes
We’ve shared some wonderful bath bomb formulas over the years. Check out the following recipes for inspiration!
- Chocolate Peppermint Bath Bombs
- Milk & Honey Hearts
- Bath Tub Whoopie Pies
- Easy Bath Tub Fizzies
- Coco Lime Bath Cookies
- Rainbow Sprinkle Bath Tub Cookies
Usage
Using a bath bomb is the funnest, and easiest step. Simply drop the bomb into a warm tub of water and enjoy the bubbles and scent.
Bath Bomb Ingredient Kits
From Nature With Love carries two great ingredient kits to help you get started. Each kit comes with Citric Acid, Baking Soda, a copy of Elaine Stavert’s Bath Bomb Book, and a variety of additional ingredients.
Our All Natural Bath Bomb Kit comes with a variety of natural herbs, clays, and aromatics that you can use to create beautiful, eco-friendly bath bombs.
Our Classic Colors & Scents Bath Bombs Kit includes a selection of fun Colorants and Fragrance Oils. Use this kit to create bright colored, strong scented bath bombs.
Thank you for providing a “Ratio” recipe. I’m trying my hand at making Bath Bombs tomorrow for the first time. This is just the kind of guide I was looking for.
Hi Karen. Im glad that our Bath Bomb post has been helpful. A lot of bath and body recipes can be broken down into ratios, allowing you to get creative with your ingredients, and make something totally unique. Let us know what you come up with for your own bath bombs. Wed love to hear about your recipes, or better yet, see pictures!
I am new to bath bomb making but I want to use 100 percent natural ingredients. I made a few white ones with essential oils for fragrance and they turned out great. Next I’d like to add a natural colorant. Do you suggest clays for this and how to do incorporate them in the mix? Thanks!
Hi Beth. The best clays for adding natural color to bath bombs would be White Kaolin, Yellow Kaolin, Pink Kaolin, and French Green Clay. Keep in mind that clays will only impart very subtle colors and tones to bath bombs. Some other all-natural ingredients that can be used to give bath bombs color are Green Tea Powder, Cocoa Powder, and Cranberry Fruit Fiber. For bolder color, check out our collection of Ultramarines and Oxides. You can see some examples of colored bath bombs at the following blog post: https://naturalbeautyworkshop.com/my_weblog/2009/02/bombs-away-new-bath-bomb-kits-at-fromnaturewithlovecom.html
if you used a combination of oil and water as a binding agent what else is needed do I need any other ingredient to hold the oil and water together or would it be ok to mix the oil with dry ingredients the spritz the water on or have I got it all wrong thanks
Charles Halewood
It’s recommended to use either oil or water as a binding agent. Generally, you don’t see folks using a combination of both very often. If you did want to, I’d recommend drizzling the melted butter in first, and mixing it in well, (make sure it is something that will harden, like Cocoa Butter) then spritzing the water in to finish the job.
It’s much easier to add the citric acid AFTER everything else has been blended together – that way, it’s not reacting before you’re ready to mold.
That’s a great tip, Susanna. We’ll have to try that during our next batch of bath bombs.
Hi, this all looks really exciting. I have just redecorated my bathroom in a French rustic style and am now looking for some luxurious way to indulge my self and enjoy my new space, and for my visitors to choose something that they might enjoy also.
I am in New Zealand, and am wondering where I can get the clays and colorants ?
Even if I have to buy them overseas, a little would probably go a long way ?
I thought perhaps even freeze dried powdered fruit – like raspberry, strawberry could work for colour and extra perfume.
thanks,
Tania
Congratulations on your newly decorated bathroom, Tania! It sounds beautiful!
From Nature With Love does ship to New Zealand, and has a vast selection of all sorts of ingredients to choose from (including clays, oils, essential oils, and other natural items). After you add items to your cart, choose the option to view your cart. You’ll see a section where shipping charges can be estimated based on shipping destination.
From Nature With Love also offers a selection of natural ingredients that impart color to products (including raspberry powder and cranberry fruit fiber), but these products typically don’t contribute much to the scent of the finished products. You can see the selection here: http://www.fromnaturewithlove.com/soap/ColorAdd.asp#NatTint
Keep us posted on what you come up with for your own personal bath bombs!
Hi, I was wondering if you know of anyone is Seattle, WA who do bath bomb workshops. I have been searching and searching and have no luck. If you have any idea please let me know.
There is a soap making workshop in Bellingham named Otion, which is about 1 hour from Seattle. (http://www.otionsoap.com/) They may offer classes on bath bombs as well. As far as classes in Seattle proper, I’m afraid I don’t know of any to recommend. You can check out of Instructor Directory for more options. I believe there are some other instructors in Washington listed there. https://www.fromnaturewithlove.com/instructordirectory/default.asp
I use beet powder for coloring. However, after some time has gone by the color fades out. Is there a binder for the beet powder that I can use so the don’t fade?
Unfortunately natural colorants aren’t known for their stability. They do have a tendency to morph or fade over time. How much so depends on a few factors – often pH level, exposure to heat and light, time, and moisture are the biggest contributors to changes in color. If you can look at your product and find a way to stabilize any of those factors, whether in packaging, process, or formula, you may be able to get the color to last longer. There is no special additive that can do that since the cause of the fading depends on so many things. I hope this helps!
Hiya , have you ever used cocoa husks ground up in your bath bombs.I have ground them up to almost powder and was wondering if they would have an irritant effect.
I have used a combination of coconut oil and rosewater effectively , again its not rock hard but it hardens enough to hold its shape.
I’ve never experimented with this myself, but it is worth a try! Another thought would be to use Coconut Flour as it has a very fine texture, one that wouldn’t irritate the skin or cause the texture of the bomb to be too course.
Interresting article. I was really looking for a complete description for the ratios of ingredients. Answered a lot of questions but still have one. Should the ingredients be measured according to weight (grams) or volume (ml)?
Hello Fred, measuring in weight is always best to ensure accuracy.
Hello!
I used a recipe based on your suggested percentages and my mixture was not holding half way through the molding process. I had success with he first 6 but the remaining pieces were a struggle to mold (not sticking).
I used 3.6 oz of coconut butter and 1 oz. combination of water/91% isopropyl alcohol. I combined them and added them to my dry mixture of 48.65 oz.
My recipe included milk, arrowroot powder, coconut flour, borax, lathanol (for bubbles) and a bit of dead sea salt.
Any suggestions would be greatly appreciated.
Adrienn