Cannabutter Method #1
Crumble (or crush) some cannabis tops, enough to fill a pot or a double boiler roughly 1/3 full. Using a mixture of 1-part butter and 4-parts water, fill the pot until it is about 3/4 full. Bring the mixture to a boil and cook for 30 minutes. Stir frequently.
After 30 minutes, remove debris from the bottom of the pot. Strain with cheesecloth or a fine mesh strainer.Cool at room temp and then transfer to a refrigerator. The butter will form on the top and, once it has been thoroughly cooled, will harden so it can be removed from the pot. After removing the butter, discard the remaining water.
Cannabutter Method #2
Using a saucepan or a double boiler, melt butter. Sift the marijuana and add it to the melted butter. Allow the mixture to simmer until the butter becomes green in color. Pour the mixture through cheesecloth or a fine mesh strainer and press that saturated cannabis to squeeze out as much butter as possible. Repeat this if extra potency is required (be sure to use the same butter for best results).
The cannabutter can be effectively frozen if it needs to be stored. It can also be stored in the refrigerator by pouring cold water over the top of the butter (the water keeps oxygen from reaching the butter and also stops the butter from floating to the top).