Infusing in butter is a waste
Why would you infuse in butter? It's only 5% fat and is extremely low in medium-chain-triglycerides - you are not getting all those goodies out of your material and into a bio-available form.
On the other hand, coconut oil is 100% fat and 66% of that is in the form of medium-chain-triglycerides....it is FAR SUPERIOR.
At any rate, just using coconut oil is not even the half of it....there are a lot of factors in play when infusing THC into ingestible formats. Go to grasscity.com and search the forum section for the thread "incredible edibles". I found it a couple of weeks ago and it has literally changed my life.
The thread will blow you away, and I can attest that BadKittySmiles' Canna Oil recipe (on page 22 of the thread) works so well you won't even be putting butter on your morning toast - you will have forgotten what butter is! :D