Always Decarb or yer in for alot of wasted material: Put an Oz of good bud not ground, but only partially broken up, or three Oz of trim in a quart mason jar and screw lid on tight, but don't crank it. Preheat oven to 250 F. Put jar or jars in the oven for 30-40 min if yer oven holds a decent temp, 20-30 min if it fluctuates and gets hot.
Cannabutter: Bring two quarts (or more) water to a boil, and reduce heat. Add four sticks of butter to the simmer, and wait till it fully melts. Add the ounce of cannabis from one mason jar (don't grind it, leave it in chunklets) to the super low simmer. Keep the simmer super low. Stir once in a while. It's important to keep at least 3 inches or so of water under the cannabis chunklets... it's important to keep them off the bottom and direct heat. Let simmer for 45 min.
Filtering/separation: Place two layers of cheese cloth in a 4 qt pyrex bowl. Gently pour the hot water/butter/cannabis mix on top of the cheesecloth in the bowl. Gather the edges of the cloth up and pull it out of the bowl and suspend it above the bowl to drip. Once it's cool enough squeeze the last water/butter outta the plant material in the cheesecloth. Place bowl of water/butter mix into the fridge and leave it be for a few hours to overnight. The water and butter will seperate and the butter (now green) will harden. Cut a small wedge into each side of the butter and pour off and discard the water layer under the butter. Some times I remove and pat dry the underside of the butter disc, sometimes I don't bother. Bring a sauce pan of water to a gentle boil. Place the bowl with the cannabutter ontop as a doubleboiler. Once the butter is melted, pour it into a butter mold or mason jar and freeze. If left in the fridge it can go bad in as soon as a week.
Use responsibly.