How to Make Cannabis Bath Bombs at Home

Making cannabis bath bombs takes four steps: decarb the flower, infuse it into oil, mix the dry ingredients, then bind with the oil and a small amount of liquid. A standard batch uses 1 cup baking soda, 1/2 cup citric acid, 1/2 cup cornstarch, 1/2 cup Epsom salt, and 2 tablespoons of infused oil. That fills about 12 molds.

thc bath bombs vs cbd bath bombs

What you need

• 7 to 14 grams of dried cannabis flower
• 1 cup coconut oil
• 1 cup baking soda
• 1/2 cup citric acid
• 1/2 cup cornstarch
• 1/2 cup Epsom salt
• 1 to 2 teaspoons polysorbate 80
• Witch hazel in a spray bottle
• Bath bomb molds
• Sheet pan lined with parchment
• Kitchen scale

Step 1: Decarboxylate the flower

Raw cannabis holds THCA and CBDA. Heat converts them to THC and CBD. Spread ground flower on a parchment-lined sheet pan in a single layer. Bake at 240°F for 30 to 40 minutes. Stir at the 15-minute mark. The flower should look dry and smell toasted. More heat or more time breaks THC down into CBN, which is less potent.

Cannabis Bath Bombs Review: The Ultimate Guide for Relaxation and Immersion

Step 2: Infuse the oil

Combine the decarbed flower with 1 cup of coconut oil in a double boiler or a mason jar set in a water bath. Hold the temperature between 160°F and 200°F for 2 to 3 hours. Stir every 30 minutes. Strain through cheesecloth and squeeze the cloth to recover the oil trapped in the plant matter. Coconut oil is solid below 76°F, so it keeps the finished bomb firm.

thc bath bombs vs cbd bath bombs

Step 3: Mix the dry ingredients

Whisk the baking soda, citric acid, cornstarch, and Epsom salt in a bowl. Break up clumps with a fork. Citric acid pulls moisture from the air, so work in a dry room and keep the bowl covered between steps.

Step 4: Add the oil and bind

Pour in 2 tablespoons of infused oil and 1 to 2 teaspoons of polysorbate 80. Mix with a fork until the texture looks like damp sand. Polysorbate 80 is an emulsifier. It disperses the oil through the bath water instead of letting it float on the surface as a slick. Spritz witch hazel over the mixture and press a handful in your fist. It holds shape when the mix is ready. Do not pour water straight into the bowl. Water starts the fizzing reaction too soon.

Step 5: Mold and dry

Pack the mixture into molds and press hard. Tap each bomb out onto parchment. Let them cure at room temperature for 24 to 48 hours, away from steam and humidity. Store in an airtight jar.

Dose per bath bomb

Potency depends on the flower and the recipe. One example: 7 grams of flower at 15% THC holds about 1,050 mg of THC. That infuses into 1 cup of oil, or 48 teaspoons. A batch uses 2 tablespoons (6 teaspoons) of that oil and makes 12 bombs. Each bomb then carries 0.5 teaspoon of oil, or about 1/96 of the cup. The dose lands near 11 mg of THC per bomb. Test one bomb before using a second.

Absorption and limits

Cannabinoids are fat-soluble and poorly water-soluble. Skin absorbs them at a slow rate compared with inhalation or edibles. A bath bomb is a topical product, and for most users the effect stays local. Hot water opens pores and raises blood flow, which can increase absorption. Some users report no psychoactive effect at all. Keep the water out of your eyes and rinse the tub after use to remove oil residue.

Cannabis is a Schedule I controlled substance under US federal law. State rules on homemade cannabis products differ, and some states cap potency or ban home infusion. Check your state law before you buy flower or share the finished product.