How to Make Cannabutter in a Slow Cooker (Crock Pot Recipe and Dosage)

Updated 4 November 2026Dosing based on Health Canada guidanceFor adults where cannabis is legal

Can you make cannabutter in a slow cooker?

Yes. A slow cooker, or crock pot, is popular for cannabutter because it holds a low, steady heat for hours with little attention. You can leave it on low without the risk of a stovetop pan boiling dry or scorching.

There is one catch. Raw cannabis contains mostly THCA, which is not intoxicating. Heat turns THCA into THC in a process called decarboxylation. A slow cooker on low runs at or below the boiling point of water, which is too cool to do this efficiently.

In a 2016 study published in Cannabis and Cannabinoid Research, THCA in cannabis extract dropped to near zero after 30 minutes at 110°C (230°F). That is why most cooks decarboxylate in the oven first, then use the slow cooker only to infuse.

What you need

• Cannabis: 7 to 10 grams of dried flower per cup of butter is a common starting ratio. Less makes milder butter.
• Butter: 1 cup (2 sticks, 227 g) of unsalted butter. Ghee or coconut oil also work.
• Water: 1 cup. It protects the butter from scorching.
• Equipment: a slow cooker, baking sheet, parchment paper, cheesecloth or a fine strainer, and a glass container.

A small 1.5- to 3-quart slow cooker suits a single batch best. In a large cooker, a cup of butter and water spreads thin and can cook down faster.

How to make cannabutter in a slow cooker

Step 1: Decarboxylate the cannabis

1. Heat the oven to 230 to 240°F (110 to 115°C). Use an oven thermometer if your oven runs hot.
2. Break up the flower into small pieces, about the size of rice grains. Do not grind it to powder, which makes the butter taste grassy and harder to strain.
3. Spread it out on a parchment-lined baking sheet in one layer.
4. Bake for 30 to 40 minutes, stirring once halfway. It should turn light golden-brown and dry, not dark.

Step 2: Infuse in the slow cooker

1. Add the butter and water to the slow cooker and set it to low until the butter melts.
2. Stir in the decarboxylated cannabis. Make sure it is fully covered by the liquid.
3. Cover and cook on low for 4 to 8 hours. Stir every hour or two. Add a little hot water if the level drops a lot.
4. Do not use high. The mix should barely simmer, never boil hard.

Step 3: Strain, chill and separate

1. Strain the warm mix through two layers of cheesecloth into a glass bowl or jar. Press gently. Squeezing hard pushes more plant taste into the butter.
2. Chill in the refrigerator for a few hours or overnight. The butter rises and sets on top.
3. Lift off the butter and pour away the water underneath. Pat the butter dry with a paper towel.
4. Label it clearly with the date and the estimated strength.

Mason jar method in a slow cooker

This works like a double boiler and keeps the smell down. The butter infuses inside a sealed jar while the slow cooker heats the water around it.

1. Fill a jar. Put the decarboxylated cannabis and butter in a heat-safe mason jar, leaving about an inch of space at the top. Close the lid finger-tight.
2. Protect the jar. Put a folded towel or a small rack in the bottom of the slow cooker, so the glass does not sit directly on the hot base.
3. Add warm water. Stand the jar in the cooker and add warm, not cold, water up to the jar’s shoulder. Sudden temperature changes can crack glass.
4. Cook on low for 4 to 8 hours. Lift and gently swirl the jar every couple of hours using a jar lifter or oven mitt.
5. Strain through cheesecloth while warm. No water separation is needed with this method.

How strong is homemade cannabutter?

You can estimate the maximum strength from the THC percentage on your cannabis. Multiply grams by the THC percentage to get the THCA, then multiply by 0.877. That factor accounts for the weight lost when THCA becomes THC.

Real butter will be weaker than this maximum, because decarboxylation and infusion are never complete. Treat the numbers below as an upper limit, not a guarantee. One cup of butter holds 48 teaspoons.

For example, 7 grams at 15% THC contains 1,050 mg of THCA. Multiplied by 0.877, that is about 920 mg of THC at most, or about 19 mg per teaspoon. A 2.5 mg starting serving could be as little as ⅛ teaspoon.

Dosing and safety

Health Canada advises people new to edibles to look for products with 2.5 mg of THC or less. It says effects are felt within 30 minutes to 2 hours, and can take up to 4 hours to peak. Wait before eating more.

• Mix it evenly. Stir cannabutter thoroughly into batter so every piece has a similar amount.
• Cut small portions and know how many servings the whole recipe makes.
• Do not mix with alcohol, and do not drive after eating edibles.
• Store it locked away from children and pets, in a labeled container that does not look like ordinary butter or snacks.
• If a child eats some, call Poison Help at 1-800-222-1222 in the US, or 911 if symptoms are severe.

How to store cannabutter

Keep cannabutter covered in the refrigerator and use it within a couple of weeks. For longer storage, freeze it in small labeled portions, such as an ice cube tray, then move the cubes to a freezer bag.

Removing all the water after chilling helps it keep longer, because water left in the butter encourages spoilage. Throw it away if it smells sour or shows mold.

Troubleshooting

Frequently asked questions

The bottom line

To make cannabutter in a slow cooker, decarboxylate the cannabis in the oven, infuse it with equal parts butter and water on low for 4 to 8 hours, then strain, chill and separate.

Estimate the strength before you bake with it, start with a tiny serving, and label and lock it away. For other ideas on what your cooker can do, see our guide to melting chocolate in a slow cooker.