Learn How to Make Charcoal Soap (and how much to use for shades of gray to black)

Charcoal soap…. are you wondering how much charcoal do you add for a black bar of soap? It’s one of the most frequently asked questions in soap making, but unfortunately, the answer is “it depends”. There are many variables that affect how much charcoal you need in your soap, and the amount you ultimately use will depend on those variables and what kind of look and feel you want in your finished soap.

What is Activated Charcoal

Charcoal has been used for centuries to help purify the body and skin, and it’s become a popular ingredient in soap. But what is it?

Activated charcoal is a dark black powder produced by processing bamboo, coal, or coconut shells at high temperatures (they are all carbon-rich and result in a very fine powder). This powder acts like a giant sponge which provides the adsorbing power of charcoal. That adsorbing power is why charcoal is added to soaps. We’ll, that, and the lovely colors it can make!

In the US, activated charcoal is a Generally Recognized As Safe (GRAS) product that is accepted for internal and topical use.

Uses for Activated Charcoal

In skincare, activated charcoal is touted as being beneficial for oily or acne-prone skin while still being suitable for most skin types. Although, those with very dry skin can find it to be a bit too drying. Activated charcoal is also said to help remove impurities from the skin’s surface by trapping bacteria and other substances on its super absorbent surface.

Internally it can be used to adsorb toxins, before absorption, and flush them from your system. It’s even used in treatments for poisoning, as a deodorizer, a digestive aid, and to filter water! It’s pretty cool stuff 😊

Oh, one thing to keep in mind too: Activated charcoal is NOT the same kind of charcoal you use for a BBQ. Those charcoal briquettes are not suitable for ingestion or for soaping!

But what we’re here to talk about is using activated charcoal to color our handmade soaps!

Hardwood vs. Coconut Charcoal Soap

As the names imply, hardwood charcoal is made from hard woods (like oak and maple) while coconut charcoal is made from coconut shells.

The material is super heated and the resulting charcoal is exposed to high temperatures to oxidize. It then gets “activated” through the use of steam or air which causes the charcoal to develop very tiny pores. These pores are the key to it’s super absorptive and adsorption properties (the binding or trapping of molecules and chemicals).

Coconut (and bamboo) Activated Charcoal is has both internal and external uses. They are also harder to clean or scrub off because they both create a very fine fluffy powder.
Coconut Activated Charcoal:

• Aids Digestion and can help with detoxification as it adsorbs harmful toxins in our bodies (some people even take it as a hangover cure!)
• Can strengthen weak hair (by adding some to your shampoo)
• Great for odor control (micro pours all the charcoal to absorb odors fast!)
• For skin treatments it can be used in soaps, as part of a poultice, or alone by wrapping a charcoal soaked cloth over the skin.

Hardwood charcoal is great for external use, and it’s easier to clean up vs. the fluffier coconut charcoal. The really cool thing about it is is absorbs other color molecules, so it can whiten things like your teeth. It’s does a decent job of easing bug bites when made into a basic poultice. And, it’s can control oiliness and breakouts of acne as it penetrates through the pores and does a great job at removing dirt and makeup from the skin.

Coconut vs. Hardwood activated charcoal soap:

• Coconut charcoal is harder to clean up than hardwood charcoal.
• Hardwood charcoal can be considered “scratchier” then coconut charcoal.
• Coconut charcoal is blacker than hardwood charcoal.
• Hardwood charcoal makes lovely grays and is easier to work with than coconut charcoal if you want gray vs. black soap.

How to Add Activated Charcoal to Your Soap

When adding activated charcoal to your soap, you have a few options. And, there’s no need to infuse charcoal with oils. It’s one of those awesome colorants that we can add without any preparation!

• Make a water slurry with hardwood charcoal as the water helps is disperse better. Although oil can work too.
• Make an oil slurry with any type of charcoal. This helps keep the fluffy coconut powder under control, and helps prevent clumps in your batter if you’re concerned about that.
• You can also add it directly to the batter (which is what I do with coconut charcoal).

Cold process soap charcoal soap

In cold process soap, add your charcoal to your formula at anytime. If you’re splitting your batter for multiple colors, you can easily make one portion black by adding the charcoal after emulsion.

Hot process soap charcoal soap

In hot process soaps, I like to add the charcoal to the oils before the cook. It helps me ensure that I’ll get an even disbursement of color throughout the batch. Here’s a video for your reference too =)

Activated Charcoal Soap Color Guide for Soapmakers

Activated charcoal usage rate: The standard recommendation for activated charcoal is to use 1/8 up to 1tsp of charcoal per pound of oil (PPO). This means that for every pound (454g) of oil in your formula, add anywhere from 1/8 to 1tsp of charcoal to obtain a range of grays to blacks. Any more than 1tsp PPO and you risk ending up with gray lather.

For those that know me well, you know that I much prefer to use a ratio of oil weight in grams vs. the PPO method. Why? Because a tablespoon is different each time you use it (not to mention that different parts of the world have different sizes of teaspoons!). However, I do gracefully try to embrace the PPO when it comes to charcoal and small batches. Since charcoal is so very light, those measuring spoons are sometimes the best method.

In my top selling charcoal bar, I use a ratio of 1:310. That means 1g of charcoal for every 310g of oils to get a rich dark black. If I wanted to make a pound of gray soap, well, I would be attempting to measure in fractions of grams which most scales don’t to very well. So, I add a “little bit” at a time with a very small spoon.

How to get jet black charcoal soap with activated charcoal

This has got to be the most common activated charcoal question I see in my Facebook group – how to get a BLACK black from activated charcoal (without staining your wash cloths).

• First, use coconut charcoal. It’s blacker than hardwood.
• Next, blend your colors! As I explain in my book, there are many shades of black. And, black is a mix of all colors. In fact, you can have oodles of fun creating different shades and tints of black by adding different colors to darken your black! My favorite jet black comes from adding coconut activated charcoal to an otherwise blue or purple soap.
• To ensure a midnight jet black, make sure you gel your CP soap. HP soaps always gel (love that hot processing!) and will always result in a richer black than a cold process equivalent.

And finally, here’s a sampling of the black charcoal soaps from my book along with other charcoal soaps I’ve made over the years. I’ll continue to update this section, so be sure to check back as I make more charcoal soaps for your reference!

Pro Tip: How to Clean Up Activated Charcoal Spills

Let’s face it, working with activated charcoal is messy! And spills are bound to happen even to the best soap makers out there. Here are my tips for cleaning up (and avoiding spills) when working with activated charcoal.

Don’t use activated charcoal out of a bag. Every time you open that bag, a poof of black powder will emit out and cover your work space. Transfer your activated charcoal to a jar or other container with a screw top lid.

If you’re extra messy (like I tend to be) you can keep your jar in a bag!. This helps contain any bits of powder that poof out when you scoop.

Speaking of scooping, scoop, don’t pour, out of your jar. Use a large of a utensil as you can to scoop so you only have to scoop once. Wipe the scoop off on a cloth before setting it down. The charcoal will spread from the scoop to everywhere!

To clean up any spills that do happen, I like to moisten the surface before I wipe. If you wipe dry activated charcoal, you’re just going to smudge it around your surface. I use a fine mist spray bottle and gently cover the area with soapy water. I then slowly wipe the moistened surface with a clean rag, changing rags between each wipe – again, to avoid just spreading the charcoal around.

If your surface is porous, a few things will happen:

If there was a stain (like the turmeric you spilled last week🤣) you’ll notice that the charcoal might have cleaned that up for you!

You might also notice charcoal “stains” on your surface. These will eventually fade and can be cleaned up after many scrubbings. You can even try spreading a little coconut oil on the surface, and then washing with soap and water.

If you’re soaping on your beautiful quarts or granite counter tops, stop. Stop right here and now and put some freezer paper down! You will spill your charcoal. You will have black smudgy spots all over your counter top. Your spouse will consider banning you from soaping in your kitchen!

To get charcoal off of your hands, slather on some coconut oil, massage, and then wash with soap and water.

How to Fix a Failed Activated Charcoal Soap

If your charcoal soap is a “fail” because it should be black, but came out gray. Or, it’s a great black but leaves black mess every time you use it, consider rebatching it! The Rebatching Tutorial includes formulas and recipes for both basic rebatches and partial rebatches. And it includes the recipe for my Christmas Coal Soaps! Those failed charcoal soaps will make some great holiday treats for both the naughty and the nice on your holidays list!