The Complete DIY Guide to Making Activated Charcoal

Activated charcoal, sometimes called activated carbon, is useful for purifying contaminated water or polluted air. In emergency situations, activated charcoal can be used to remove dangerous toxins and poisons from your body. First, we’ll show you how to make homemade charcoal by burning wood or fibrous plant material. Then, we’ll walk you through how to activate the charcoal with chemicals like calcium chloride or lemon juice, which will make the charcoal more porous. Let’s get started!

How to Activate Charcoal: Quick Steps

Place hardwood or coconut shells in a metal container with holes in the lid.
Burn the wood for several hours, until it turns to charcoal. Let it cool.
Rinse the charcoal with distilled water, then let it dry.
Grind the charcoal into a coarse powder.
Mix the charcoal with a solution of 1 part calcium chloride and 3 parts water.
Drain the solution after 24 hours and rinse the charcoal well.
Allow the activated charcoal to dry fully, then store in an air-tight container.

Section 1 of 5:

Making the Charcoal

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1
Pack a metal pot with small pieces of hardwood. Use dry pieces of wood that are no more than 3 in (7.6 cm) in diameter to ensure they burn all the way through. Put the wood into a metal container with a lid, like a camp kettle, non-coated paint can, garbage bin, or oil drum. Drill 5–6 small airholes into the lid if there aren’t any.^{[1]
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- If hardwood is not available, you can substitute almost any dense, fibrous plant material, like coconut shells or palm fronds.
- Do not use treated or painted wood. Also, avoid softer woods like pine, since they’ll likely just turn to ash.
- Do not use storebought charcoal—it usually contains chemical additives that would make the activated charcoal unsafe for filtering.
2
Place the pot in a well-ventilated, fire-safe area. You’ll need a big fire that burns for a while, so it’s probably best to do this in an outdoor fire pit. But if your container is small enough, you could do it in a fireplace or wood-burning stove, if you need to.
- Take safety precautions when lighting a fire—wear long sleeves and pants to protect yourself from popping embers, and always keep a fire extinguisher nearby.
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3
Cook the pot on an open fire for 3 to 5 hours to make charcoal. Pile limbs, brush, or firewood on top of the container of firewood, then start a fire. Let it burn for several hours, adding more material as needed to keep it going. The hardwood will catch on fire inside the pot. This will burn away everything from the material except the carbon (charcoal) in it. As the material cooks, you should see smoke and possibly flames escape from the vent holes in the lid. When no more smoke or gas seems to be coming from your pot, it’s likely finished cooking.
- The exact amount of time you need to keep the fire burning will depend on the size of the wood you’re using—bigger pieces of wood will need more time to burn all the way through the center. Try to use pieces of wood that are roughly the same size so they’ll burn at about the same speed.
- If you’re not experienced with burning wood, it might take a few tries to get the timing right. If you don’t burn the fire long enough, the wood might not carbonize all the way through, but if it burns too long, the wood will turn to ash.
- If you’re using a large drum, you can make a self-contained fire. Prop up the drum on stones or bricks, then ignite the fire through holes drilled into the bottom. Once the material inside starts burning, carefully seal the container, then let the it smoulder for 2–3 hours or until everything inside is carbonized.^{[2]
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Let the charcoal cool, then sort through it to remove unburned pieces. The charcoal in your pot will stay hot for a while. Give it plenty of time to cool down—at least 2–3 hours, but up to overnight if you can. Once the container is cool to the touch, transfer the charcoal to a clean container, then sort through it. Discard anything that didn’t burn all the way through (or return it to your burn pile for the next fire).
- Wood or plant matter that has fully carbonized will be lightweight, easy to break, and black all the way through to the center. If it didn’t burn well enough, it might be hard to break, and the center might be white or brown.^{[3]
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Rinse the charcoal with distilled water. Rinse it with cool water to remove ash, chemicals, or debris. Drain the water, then rinse the charcoal one more time and drain it again.^{[4]
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- If you only have access to tap water, run it through a water filter to remove any chemicals or impurities.
Let the charcoal sit out for about 24 hours or until it’s completely dry. If you’re in a hurry, spread the powder on a baking sheet and put it on low heat for about 2 hours in an oven, or high heat for around 5 hours in a dehydrator. The charcoal needs to be completely dry before you can move on.^{[5]
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Break up the charcoal into a coarse powder. Transfer the cleaned charcoal to a mortar and pestle and grind it up into a chunky powder.^{[6]
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- You could also use a blender or spice grinder, if you prefer.
- Avoid breathing in the dust created from this step. For the best protection, wear a respirator.
- Transfer the charcoal powder to a glass or steel container when you’re finished.

Section 2 of 5:

Activating the Charcoal

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1
Carefully combine 1 part calcium chloride and 3 parts water in a glass or steel bowl. Add the calcium chloride to the bowl first, then carefully stir in the water. Don’t touch the mixture as you’re doing this—a chemical reaction will occur that causes the solution to get extremely hot.
- For instance, you might mix 100 g (3.5 oz) of calcium chloride with 1.3 cups (310 ml) of water.^{[8]
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- Improperly handling or using chemicals like calcium chloride can be hazardous. Always follow the safety procedures listed on the label of chemicals.
- If you can’t find calcium chloride, use a mixture of 1 part lemon juice and 3 parts distilled water instead.^{[9]
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Mix the calcium chloride solution and charcoal powder to make a paste. Carefully stir the calcium chloride solution into the container holding the charcoal powder. Keep adding the liquid until the mixture has the consistency of a thick paste.^{[10]
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- Cover the container and let the charcoal sit for 24 hours.^{[11]
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Drain the charcoal through a mesh strainer, then rinse well. After about 24 hours, pour the charcoal from a container through a filter, like a mesh strainer or coffee filter. Then, pour distilled water over the activated charcoal to rinse away any remaining ash or residue from the calcium chloride. Rinse the charcoal 2–3 times to be thorough.^{[12]
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- Some people strain the water they get from rinsing the activated charcoal, while others discard it.
4
Dry the activated charcoal powder thoroughly. Spread the charcoal powder onto a baking sheet lined with parchment paper. It will probably be a little crumbly—that’s okay.^{[13]
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Research source} Allow it to air dry for up to 24 hours.
- For faster drying, place the baking sheet in the oven on the lowest heat setting for about 2 hours or until it’s completely dried. You can also place it in a pot over low heat for about 3 hours, if you prefer.
5
Store the activated charcoal in an airtight container. Pour the powder into a jar and seal it tightly to keep out moisture. If you’d like, you can add a silica packet to help prevent moisture from clumping up the charcoal powder.
- If the activated charcoal powder is too clumpy, break it up more in a mortar and pestle, spice grinder, or blender.^{[14]
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Section 3 of 5:

What’s the difference between charcoal and activated charcoal?

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Activated charcoal is more porous than regular charcoal. Charcoal is the solid, dried-out carbon left behind after burning hardwood or other plant material. Activated charcoal is regular charcoal that has been treated with steam or a chemical like calcium chloride. This creates pores and fissures in the surface of the activated charcoal, significantly increasing its surface area.^{[15]
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- Charcoal and activated charcoal are both adsorbent (meaning things stick to their surfaces). The extra surface area of activated charcoal makes it more adsorbent, so it’s especially good at removing impurities from the air or water.

Section 4 of 5:

What is activated charcoal used for?

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Activated charcoal can remove allergens, bacteria, and more from air and water. It works by trapping odors, toxins, bacteria, pollutants, allergens, and chemicals into the numerous tiny pores within the charcoal. Here are some handy, concrete ways to use activated charcoal in your home:
- Purify the air in your home. Wrap some activated charcoal in a linen or cotton cloth, then place it in a ventilated area so it can absorb odors.
- Make a charcoal water filter by filling a clean sock with activated charcoal. Then, pour water through the sock to clean it.^{[16]
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- Detoxify your skin with a peel-off face mask. Mix activated charcoal and non-toxic school glue to make a paste about the texture of brownie batter. Spread it onto your face, wait for it to dry, then gently peel it off.^{[17]
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- Treat bloating and gas by drinking 500 milligrams (0.02 oz) of powdered activated charcoal mixed into 12 fluid ounces (350 ml) of water. You can also mix it into a non-acidic juice (like carrot) to make it taste better.^{[18]
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- Whiten your teeth. Add a little water to finely-ground activated charcoal to make a paste. Dip your toothbrush into the paste, then use it to gently scrub your teeth. Only do this occasionally, as it can wear down your tooth enamel if you use it too often.^{[19]
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Section 5 of 5:

Can you activate charcoal using steam?

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Steam is not a reliable method for making activated charcoal at home. Industrial producers often use steam to activate charcoal. However, this method requires managing steam at a sustained temperature of around 800–1,000 °C (1,470–1,830 °F). This isn’t something that can be easily or safely replicated at home.^{[20]
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- Some people do make a simple form of activated charcoal by applying water to the charcoal while it’s still burning. However, this doesn’t create a consistent product, and it’s difficult to gauge whether the charcoal is sufficiently activated afterward.
- Homemade steam-activated charcoal might be okay for things like DIY face masks, crafts, or gardening—but if you’re relying on it for purification, a more reliable method is recommended.

Expert Q&A

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Question

What are the benefits of charcoal masks?

Joanna Kula
Licensed Esthetician
Joanna Kula is a Licensed Esthetician, Owner and Founder of Skin Devotee Facial Studio in Philadelphia. With over 10 years of experience in skincare, Joanna specializes in transformative facial treatments to help clients achieve a lifetime of healthy, beautiful, and radiant skin. She is also a contributing author for the prestigious Les Nouvelles Esthetiques & Spa magazine and has been featured in a number of magazines including InStyle.

Joanna Kula

Licensed Esthetician

Expert Answer

Charcoal masks have become very popular. The idea behind them is that the addition of charcoal can help to purify and detoxify the skin, similar to how it’s used in medicine to absorb poisonous and toxic substances in the stomach. However, there isn’t much research or evidence to support this claim.

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