Hi Amelia,
These are some good questions.
As you mention, there are different methods to preparing oil infusions and the method a person chooses is based on time constraints, volatile oils and other phytochemicals, whether the plant is fresh and personal preferences.
For the hot method extraction a person may want to use this method to shorten the duration of the maceration, but also if they are using fresh plant material. Other reasons a person may want to use the warm oil extraction is to save shelf space (this way there aren’t jars of oil macerating that need space for weeks), it thins the oil for straining or if someone want to use coconut oil, shea butter, lard, or fat of any kind.
A couple of downsides for the warm maceration is that the oil can burn if not careful (I have ruined batches in my early days), and you have to keep an eye on it throughout the process to make sure of water levels.
Personally I am a hot water method extractor all the way, 🙂 but that is mainly because of my time and space constraints along with using fresh plant material often. ‘Cold’ extractions are just as good!
I hope you have fun oil extracting ahead!
Warmly,
Benna