Lay a clean tea towel in the bottom of your crockpot to buffer the glass jar against the bottom of the crock. Add enough water to the crockpot to come at least 3/4 of the way to the top of your jar(s).
Stick a digital thermometer in your water bath and turn the crockpot on high. Allow the water bath to come up to 185°F and then turn to low.
While the crockpot is heating up, decarb your cannabis if you haven’t already. Add the oil and decarboxylated cannabis to a clean mason jar and screw on the lid finger tight.
Place your sealed jar in the crock and cook on low for four hours, maintaining a temperature of 185°F.
After four hours strain your oil and weed through a fine-mesh strainer/cheesecloth into a clean container or jar. See our straining notes.